diff --git a/.github/actions/prepare-build/action.yml b/.github/actions/prepare-build/action.yml
new file mode 100644
index 000000000000..a83f403c0ffc
--- /dev/null
+++ b/.github/actions/prepare-build/action.yml
@@ -0,0 +1,22 @@
+name: "Prepare: Build"
+description: "Prepares the repo for a job by running the build"
+# inputs:  - no inputs
+# outputs: - no outputs
+
+runs:
+  using: "composite"
+  steps:
+    - uses: actions/cache@v3
+      id: build-cache
+      with:
+        path: "**/dist/**"
+        key: ${{ runner.os }}-build-${{ github.ref }}
+        restore-keys: |
+          ${{ runner.os }}-build-
+
+    # if the cache was hit - this will run in <1s
+    - name: Build
+      shell: bash
+      # Website will be built by the Netlify GitHub App
+      run: |
+        yarn build --exclude website
diff --git a/.github/actions/prepare-install/action.yml b/.github/actions/prepare-install/action.yml
new file mode 100644
index 000000000000..73fc2191a0dc
--- /dev/null
+++ b/.github/actions/prepare-install/action.yml
@@ -0,0 +1,44 @@
+name: "Prepare: Checkout and Install"
+description: "Prepares the repo for a job by checking out and installing dependencies"
+inputs:
+  node-version:
+    description: "The node version to setup"
+    required: true
+  registry-url:
+    description: "Define registry-url"
+    required: false
+
+# outputs: - no outputs
+
+runs:
+  using: "composite"
+  steps:
+    - name: echo github.ref
+      shell: bash
+      run: echo ${{ github.ref }}
+
+    - name: Use Node.js ${{ inputs.node-version }}
+      uses: actions/setup-node@v3
+      with:
+        node-version: ${{ inputs.node-version }}
+        registry-url: ${{ inputs.registry-url }}
+
+    - name: Get yarn cache directory path
+      shell: bash
+      id: yarn-cache-dir-path
+      run: echo "::set-output name=dir::$(yarn cache dir)"
+
+    - uses: actions/cache@v3
+      id: yarn-cache
+      with:
+        path: ${{ steps.yarn-cache-dir-path.outputs.dir }}
+        key: ${{ runner.os }}-yarn-${{ hashFiles('**/yarn.lock') }}
+        restore-keys: |
+          ${{ runner.os }}-yarn-
+
+    # if the cache was hit - this will run in <1s
+    - name: Install dependencies
+      shell: bash
+      run: |
+        yarn --ignore-engines --frozen-lockfile --ignore-scripts
+        yarn check-clean-workspace-after-install
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 704793ed36f3..a2e01de99389 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -9,419 +9,189 @@ on:
       - '**'
 
 env:
-  PRIMARY_NODE_VERSION: 16
+  PRIMARY_NODE_VERSION: 18
   NX_BRANCH: ${{ github.event.number }}
   NX_RUN_GROUP: ${{ github.run_id }}
-  # Added the - at the end to function as a separator to improve readability in the PR comment from the Nx cloud app
-  NX_CLOUD_ENV_NAME: 'Node 12.x -'
 
-jobs:
-  typecheck:
-    name: Typecheck
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v3
-
-      - name: echo github.ref
-        run: echo ${{ github.ref }}
-
-      - name: Use Node.js ${{ env.PRIMARY_NODE_VERSION }}
-        uses: actions/setup-node@v3
-        with:
-          node-version: ${{ env.PRIMARY_NODE_VERSION }}
-
-      - name: Get yarn cache directory path
-        id: yarn-cache-dir-path
-        run: echo "::set-output name=dir::$(yarn cache dir)"
-
-      - uses: actions/cache@v3
-        id: yarn-cache # use this to check for `cache-hit` (`steps.yarn-cache.outputs.cache-hit != 'true'`)
-        with:
-          path: ${{ steps.yarn-cache-dir-path.outputs.dir }}
-          key: ${{ runner.os }}-yarn-${{ hashFiles('**/yarn.lock') }}
-          restore-keys: |
-            ${{ runner.os }}-yarn-
+defaults:
+  run:
+    shell: bash
 
-      - name: Install dependencies
-        run: |
-          yarn --ignore-engines --frozen-lockfile --ignore-scripts
-          yarn check-clean-workspace-after-install
+#
+# Workflow for how the CI spawns jobs:
+# 1) Run the install and cache the install artefacts
+# 2) Run the build and cache the output
+#    - In parallel we also any steps that don't need the build (like prettier)
+# 3) Run the steps that depend on the build
+#
 
-      - name: Build
-        run: |
-          # Website will be built by the Netlify GitHub App
-          yarn build --exclude website
-
-      # Note that this command *also* type checks tests/tools,
-      # whereas the build only checks src files
-      - name: Typecheck all packages
-        run: yarn typecheck
-
-  unit_test_on_primary_node_version:
-    name: Unit tests
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v3
-        with:
-          fetch-depth: 2
-
-      - name: echo github.ref
-        run: echo ${{ github.ref }}
-
-      - name: Use Node.js ${{ env.PRIMARY_NODE_VERSION }}
-        uses: actions/setup-node@v3
-        with:
-          node-version: ${{ env.PRIMARY_NODE_VERSION }}
-
-      - name: Get yarn cache directory path
-        id: yarn-cache-dir-path
-        run: echo "::set-output name=dir::$(yarn cache dir)"
-
-      - uses: actions/cache@v3
-        id: yarn-cache # use this to check for `cache-hit` (`steps.yarn-cache.outputs.cache-hit != 'true'`)
-        with:
-          path: ${{ steps.yarn-cache-dir-path.outputs.dir }}
-          key: ${{ runner.os }}-yarn-${{ hashFiles('**/yarn.lock') }}
-          restore-keys: |
-            ${{ runner.os }}-yarn-
-
-      - name: Install dependencies
-        run: |
-          yarn --ignore-engines --frozen-lockfile --ignore-scripts
-          yarn check-clean-workspace-after-install
-
-      - name: Build
-        run: |
-          # Website will be built by the Netlify GitHub App
-          yarn build --exclude website
-
-      - name: Run unit tests for ast-spec
-        run: yarn test
-        working-directory: packages/ast-spec
-        env:
-          CI: true
-
-      - name: Run unit tests for typescript-estree
-        run: npx nx test @typescript-eslint/typescript-estree
-        env:
-          CI: true
-
-      - name: Run unit tests for visitor-keys
-        run: npx nx test @typescript-eslint/visitor-keys
-        env:
-          CI: true
-
-      - name: Run unit tests for scope-manager
-        run: npx nx test @typescript-eslint/scope-manager --code-coverage
-        env:
-          CI: true
-
-      - name: Run unit tests for utils
-        run: npx nx test @typescript-eslint/utils
-        env:
-          CI: true
-
-      - name: Run unit tests for type-utils
-        run: npx nx test @typescript-eslint/type-utils
-        env:
-          CI: true
-
-      - name: Run unit tests for parser
-        run: npx nx test @typescript-eslint/parser
-        env:
-          CI: true
-
-      - name: Run unit tests for eslint-plugin
-        run: npx nx test @typescript-eslint/eslint-plugin
-        env:
-          CI: true
-
-      - name: Run unit tests for eslint-plugin-tslint
-        run: npx nx test @typescript-eslint/eslint-plugin-tslint
-        env:
-          CI: true
-
-      - name: Run unit tests for eslint-plugin-internal
-        run: npx nx test @typescript-eslint/eslint-plugin-internal
-        env:
-          CI: true
-
-      - name: Publish code coverage report
-        uses: codecov/codecov-action@v3
-        with:
-          token: ${{ secrets.CODECOV_TOKEN }}
-          files: packages/**/coverage/lcov.info
-          flags: unittest
-          name: codecov
-
-  spellcheck:
-    name: Spellcheck
+jobs:
+  install:
+    name: Checkout and Install
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
-      - name: Use Node.js ${{ env.PRIMARY_NODE_VERSION }}
-        uses: actions/setup-node@v3
+      - name: Checkout
+        uses: actions/checkout@v3
+      - name: Install
+        uses: ./.github/actions/prepare-install
         with:
           node-version: ${{ env.PRIMARY_NODE_VERSION }}
 
-      - name: Get yarn cache directory path
-        id: yarn-cache-dir-path
-        run: echo "::set-output name=dir::$(yarn cache dir)"
-
-      - uses: actions/cache@v3
-        id: yarn-cache # use this to check for `cache-hit` (`steps.yarn-cache.outputs.cache-hit != 'true'`)
-        with:
-          path: ${{ steps.yarn-cache-dir-path.outputs.dir }}
-          key: ${{ runner.os }}-yarn-${{ hashFiles('**/yarn.lock') }}
-          restore-keys: |
-            ${{ runner.os }}-yarn-
-
-      - name: Install dependencies
-        run: |
-          yarn --ignore-engines --frozen-lockfile --ignore-scripts
-          yarn check-clean-workspace-after-install
-
-      - name: Check spelling
-        run: yarn check-spelling
-
-  check_format:
-    name: Check Format
+  build:
+    name: Build All Packages
+    needs: [install]
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
-      - name: Use Node.js ${{ env.PRIMARY_NODE_VERSION }}
-        uses: actions/setup-node@v3
+      - name: Checkout
+        uses: actions/checkout@v3
+      - name: Install
+        uses: ./.github/actions/prepare-install
         with:
           node-version: ${{ env.PRIMARY_NODE_VERSION }}
+      - name: Build
+        uses: ./.github/actions/prepare-build
 
-      - name: Get yarn cache directory path
-        id: yarn-cache-dir-path
-        run: echo "::set-output name=dir::$(yarn cache dir)"
-
-      - uses: actions/cache@v3
-        id: yarn-cache # use this to check for `cache-hit` (`steps.yarn-cache.outputs.cache-hit != 'true'`)
-        with:
-          path: ${{ steps.yarn-cache-dir-path.outputs.dir }}
-          key: ${{ runner.os }}-yarn-${{ hashFiles('**/yarn.lock') }}
-          restore-keys: |
-            ${{ runner.os }}-yarn-
-
-      - name: Install dependencies
-        run: |
-          yarn --ignore-engines --frozen-lockfile --ignore-scripts
-          yarn check-clean-workspace-after-install
-
-      - name: Lint markdown
-        run: yarn lint-markdown
-
-  markdownlint:
-    name: Markdownlint
+  lint_without_build:
+    name: Lint
+    needs: [install]
     runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        lint-task: [
+          "check-spelling",
+          "check-format",
+          "lint-markdown",
+        ]
     steps:
-      - uses: actions/checkout@v3
-      - name: Use Node.js ${{ env.PRIMARY_NODE_VERSION }}
-        uses: actions/setup-node@v3
+      - name: Checkout
+        uses: actions/checkout@v3
+      - name: Install
+        uses: ./.github/actions/prepare-install
         with:
           node-version: ${{ env.PRIMARY_NODE_VERSION }}
 
-      - name: Get yarn cache directory path
-        id: yarn-cache-dir-path
-        run: echo "::set-output name=dir::$(yarn cache dir)"
-
-      - uses: actions/cache@v3
-        id: yarn-cache # use this to check for `cache-hit` (`steps.yarn-cache.outputs.cache-hit != 'true'`)
-        with:
-          path: ${{ steps.yarn-cache-dir-path.outputs.dir }}
-          key: ${{ runner.os }}-yarn-${{ hashFiles('**/yarn.lock') }}
-          restore-keys: |
-            ${{ runner.os }}-yarn-
-
-      - name: Install dependencies
-        run: |
-          yarn --ignore-engines --frozen-lockfile --ignore-scripts
-          yarn check-clean-workspace-after-install
+      - name: Run Check
+        run: yarn ${{ matrix.lint-task }}
 
-      - name: Check code formatting
-        run: yarn check-format
-
-  eslint:
-    name: ESLint
+  lint_with_build:
+    name: Lint
+    # because we lint with our own tooling, we need to build
+    needs: [build]
     runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        lint-task: [
+          "lint",
+          "typecheck",
+        ]
     steps:
-      - uses: actions/checkout@v3
-      - name: Use Node.js ${{ env.PRIMARY_NODE_VERSION }}
-        uses: actions/setup-node@v3
+      - name: Checkout
+        uses: actions/checkout@v3
+      - name: Install
+        uses: ./.github/actions/prepare-install
         with:
           node-version: ${{ env.PRIMARY_NODE_VERSION }}
-
-      - name: Get yarn cache directory path
-        id: yarn-cache-dir-path
-        run: echo "::set-output name=dir::$(yarn cache dir)"
-
-      - uses: actions/cache@v3
-        id: yarn-cache # use this to check for `cache-hit` (`steps.yarn-cache.outputs.cache-hit != 'true'`)
-        with:
-          path: ${{ steps.yarn-cache-dir-path.outputs.dir }}
-          key: ${{ runner.os }}-yarn-${{ hashFiles('**/yarn.lock') }}
-          restore-keys: |
-            ${{ runner.os }}-yarn-
-
-      - name: Install dependencies
-        run: |
-          yarn --ignore-engines --frozen-lockfile --ignore-scripts
-          yarn check-clean-workspace-after-install
-
       - name: Build
-        run: |
-          # Website will be built by the Netlify GitHub App
-          yarn build --exclude website
+        uses: ./.github/actions/prepare-build
 
-      - name: Lint code
-        run: yarn lint
+      - name: Run Check
+        run: yarn ${{ matrix.lint-task }}
 
   integration_tests:
     name: Run integration tests on primary Node.js version
+    needs: [build]
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
-      - name: Use Node.js ${{ env.PRIMARY_NODE_VERSION }}
-        uses: actions/setup-node@v3
+      - name: Checkout
+        uses: actions/checkout@v3
+      - name: Install
+        uses: ./.github/actions/prepare-install
         with:
           node-version: ${{ env.PRIMARY_NODE_VERSION }}
-
-      - name: Get yarn cache directory path
-        id: yarn-cache-dir-path
-        run: echo "::set-output name=dir::$(yarn cache dir)"
-
-      - uses: actions/cache@v3
-        id: yarn-cache # use this to check for `cache-hit` (`steps.yarn-cache.outputs.cache-hit != 'true'`)
-        with:
-          path: ${{ steps.yarn-cache-dir-path.outputs.dir }}
-          key: ${{ runner.os }}-yarn-${{ hashFiles('**/yarn.lock') }}
-          restore-keys: |
-            ${{ runner.os }}-yarn-
-
-      - name: Install dependencies
-        run: |
-          yarn --ignore-engines --frozen-lockfile --ignore-scripts
-          yarn check-clean-workspace-after-install
-
       - name: Build
-        run: |
-          # Website will be built by the Netlify GitHub App
-          yarn build --exclude website
+        uses: ./.github/actions/prepare-build
 
       - name: Run integrations tests
         run: yarn test-integration
         env:
           CI: true
 
-  unit_tests_on_other_node_versions:
-    name: Run unit tests on other Node.js versions
+  unit_tests:
+    name: Run Unit Tests
+    needs: [build]
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        node-version: [12.x, 14.x, 16.x]
+        # just run on the oldest and latest supported versions and assume the intermediate versions are good
+        node-version: [12, 18]
+        package: [
+          "ast-spec",
+          "eslint-plugin",
+          "eslint-plugin-internal",
+          "eslint-plugin-tslint",
+          "parser",
+          "scope-manager",
+          "type-utils",
+          "typescript-estree",
+          "utils",
+          "visitor-keys",
+        ]
     env:
       # Added the - at the end to function as a separator to improve readability in the PR comment from the Nx cloud app
       NX_CLOUD_ENV_NAME: 'Node ${{ matrix.node-version }} -'
+      COLLECT_COVERAGE: false
     steps:
-      - uses: actions/checkout@v3
-      - name: Use Node.js ${{ matrix.node-version }}
-        uses: actions/setup-node@v3
+      - name: Checkout
+        uses: actions/checkout@v3
         with:
-          node-version: ${{ matrix.node-version }}
-
-      - name: Get yarn cache directory path
-        id: yarn-cache-dir-path
-        run: echo "::set-output name=dir::$(yarn cache dir)"
-
-      - uses: actions/cache@v3
-        id: yarn-cache # use this to check for `cache-hit` (`steps.yarn-cache.outputs.cache-hit != 'true'`)
+          fetch-depth: 2
+      - name: Install
+        uses: ./.github/actions/prepare-install
         with:
-          path: ${{ steps.yarn-cache-dir-path.outputs.dir }}
-          key: ${{ runner.os }}-yarn-${{ hashFiles('**/yarn.lock') }}
-          restore-keys: |
-            ${{ runner.os }}-yarn-
-
-      - name: Install dependencies
-        run: |
-          yarn --ignore-engines --frozen-lockfile --ignore-scripts
-          yarn check-clean-workspace-after-install
-
+          node-version: ${{ env.PRIMARY_NODE_VERSION }}
       - name: Build
-        run: |
-          # Website will be built by the Netlify GitHub App
-          yarn build --exclude website
-
-      - name: Run unit tests for typescript-estree
-        run: npx nx test @typescript-eslint/typescript-estree
-        env:
-          CI: true
-
-      - name: Run unit tests for visitor-keys
-        run: npx nx test @typescript-eslint/visitor-keys
-        env:
-          CI: true
-
-      - name: Run unit tests for scope-manager
-        run: npx nx test @typescript-eslint/scope-manager
-        env:
-          CI: true
-
-      - name: Run unit tests for utils
-        run: npx nx test @typescript-eslint/utils
-        env:
-          CI: true
-
-      - name: Run unit tests for type-utils
-        run: npx nx test @typescript-eslint/type-utils
-        env:
-          CI: true
-
-      - name: Run unit tests for parser
-        run: npx nx test @typescript-eslint/parser
-        env:
-          CI: true
-
-      - name: Run unit tests for eslint-plugin
-        run: npx nx test @typescript-eslint/eslint-plugin
+        uses: ./.github/actions/prepare-build
+
+      # collect coverage on the primary node version
+      # we don't collect coverage on other node versions so they run faster
+      # note that we don't do this as a single `run` with a flag because some
+      # packages don't collect coverage on purpose, so forcing `--coverage=true`
+      # would override the config
+      - name: Run unit tests with coverage for ${{ matrix.package }}
+        if: env.PRIMARY_NODE_VERSION == matrix.node-version
+        run: npx nx test @typescript-eslint/${{ matrix.package }}
         env:
           CI: true
-
-      - name: Run unit tests for eslint-plugin-tslint
-        run: npx nx test @typescript-eslint/eslint-plugin-tslint
+      - name: Run unit tests for ${{ matrix.package }}
+        if: env.PRIMARY_NODE_VERSION != matrix.node-version
+        run: npx nx test @typescript-eslint/${{ matrix.package }} --coverage=false
         env:
           CI: true
 
-      # ast-spec is internal only - so don't care about compat on other versions
-      # eslint-plugin-internal is internal only - so don't care about compat on other versions
+      - name: Store coverage for uploading
+        if: env.PRIMARY_NODE_VERSION == matrix.node-version
+        uses: actions/upload-artifact@v3
+        with:
+          name: ${{ matrix.package }}-coverage
+          path: packages/${{ matrix.package }}/coverage/lcov.info
+          # Sadly 1 day is the minimum
+          retention-days: 1
 
   website_tests:
     name: Website tests
+    needs: [build]
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - name: Checkout
+        uses: actions/checkout@v3
         with:
           fetch-depth: 2
-
-      - name: echo github.ref
-        run: echo ${{ github.ref }}
-
-      - name: Get yarn cache directory path
-        id: yarn-cache-dir-path
-        run: echo "::set-output name=dir::$(yarn cache dir)"
-
-      - uses: actions/cache@v3
-        id: yarn-cache # use this to check for `cache-hit` (`steps.yarn-cache.outputs.cache-hit != 'true'`)
+      - name: Install
+        uses: ./.github/actions/prepare-install
         with:
-          path: ${{ steps.yarn-cache-dir-path.outputs.dir }}
-          key: ${{ runner.os }}-yarn-${{ hashFiles('**/yarn.lock') }}
-          restore-keys: |
-            ${{ runner.os }}-yarn-
-
-      - name: Install dependencies
-        run: yarn --ignore-engines --frozen-lockfile
+          node-version: ${{ env.PRIMARY_NODE_VERSION }}
+      - name: Build
+        uses: ./.github/actions/prepare-build
 
       - name: Cypress run
         uses: cypress-io/github-action@v2
@@ -430,62 +200,59 @@ jobs:
           start: yarn start
 
       - uses: actions/upload-artifact@v3
-        if: always()
         with:
           name: screenshots
           path: |
             packages/website/cypress/screenshots/
             packages/website/cypress/videos/
 
+  upload_coverage:
+    name: Upload Codecov Coverage
+    needs: [unit_tests]
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v3
+
+      - name: Download coverage reports
+        uses: actions/download-artifact@v3
+        with:
+          path: coverage
+
+      - name: Publish code coverage report
+        uses: codecov/codecov-action@v3
+        with:
+          token: ${{ secrets.CODECOV_TOKEN }}
+          files: coverage/**/lcov.info
+          flags: unittest
+          name: codecov
+
 
   publish_canary_version:
     name: Publish the latest code as a canary version
     runs-on: ubuntu-latest
     needs:
       [
-        typecheck,
-        unit_test_on_primary_node_version,
-        unit_tests_on_other_node_versions,
-        spellcheck,
-        check_format,
-        markdownlint,
-        eslint,
         integration_tests,
+        lint_with_build,
+        lint_without_build,
+        unit_tests,
       ]
     if: github.repository == 'typescript-eslint/typescript-eslint' && github.ref == 'refs/heads/main'
     steps:
-      - uses: actions/checkout@v3
-      # Fetch all history for all tags and branches in this job because lerna needs it
-      - run: |
-          git fetch --prune --unshallow
-
-      - name: Use Node.js ${{ env.PRIMARY_NODE_VERSION }}
-        uses: actions/setup-node@v3
+      - name: Checkout
+        uses: actions/checkout@v3
+      - name: Install
+        uses: ./.github/actions/prepare-install
         with:
           node-version: ${{ env.PRIMARY_NODE_VERSION }}
-          registry-url: https://registry.npmjs.org/
-
-      - name: Get yarn cache directory path
-        id: yarn-cache-dir-path
-        run: echo "::set-output name=dir::$(yarn cache dir)"
-
-      - uses: actions/cache@v3
-        id: yarn-cache # use this to check for `cache-hit` (`steps.yarn-cache.outputs.cache-hit != 'true'`)
-        with:
-          path: ${{ steps.yarn-cache-dir-path.outputs.dir }}
-          key: ${{ runner.os }}-yarn-${{ hashFiles('**/yarn.lock') }}
-          restore-keys: |
-            ${{ runner.os }}-yarn-
-
-      - name: Install dependencies
-        run: |
-          yarn --ignore-engines --frozen-lockfile --ignore-scripts
-          yarn check-clean-workspace-after-install
-
+          registry-url: "https://registry.npmjs.org"
       - name: Build
-        run: |
-          # Website will be built by the Netlify GitHub App
-          yarn build --exclude website
+        uses: ./.github/actions/prepare-build
+
+      # Fetch all history for all tags and branches in this job because lerna needs it
+      - run: |
+          git fetch --prune --unshallow
 
       - name: Publish all packages to npm
         run: npx lerna publish --loglevel=verbose --canary --exact --force-publish --yes
diff --git a/.github/workflows/lock.yml b/.github/workflows/lock.yml
index e088e1d85ad0..84152062b220 100644
--- a/.github/workflows/lock.yml
+++ b/.github/workflows/lock.yml
@@ -11,9 +11,9 @@ jobs:
       - uses: dessant/lock-threads@v3
         with:
           github-token: ${{ github.token }}
-          issue-lock-inactive-days: "30"
+          issue-inactive-days: "30"
           issue-lock-reason: "resolved"
-          issue-lock-comment: ""
-          pr-lock-inactive-days: "30"
+          issue-comment: ""
+          pr-inactive-days: "30"
           pr-lock-reason: "resolved"
-          pr-lock-comment: ""
+          pr-comment: ""
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 390589e4a2a5..6552077df3d7 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -3,6 +3,27 @@
 All notable changes to this project will be documented in this file.
 See [Conventional Commits](https://conventionalcommits.org) for commit guidelines.
 
+# [5.26.0](https://github.com/typescript-eslint/typescript-eslint/compare/v5.25.0...v5.26.0) (2022-05-23)
+
+
+### Bug Fixes
+
+* **ast-spec:** add `SpreadElement` to `ArrayExpression.elements` ([#5025](https://github.com/typescript-eslint/typescript-eslint/issues/5025)) ([9f3121b](https://github.com/typescript-eslint/typescript-eslint/commit/9f3121b228b9c066bff7a6011aecf269ac55f17c))
+* **eslint-plugin:** [member-delimiter-style] autofixer result is not as expected when comments after the delimiter with option `delimiter: 'none'` ([#5029](https://github.com/typescript-eslint/typescript-eslint/issues/5029)) ([ed7b5f6](https://github.com/typescript-eslint/typescript-eslint/commit/ed7b5f61d93799fec3e38a87935ab9caa3abe279))
+* **eslint-plugin:** [member-delimiter-style] autofixer result is not as expected with option `delimiter: 'none'` ([#5023](https://github.com/typescript-eslint/typescript-eslint/issues/5023)) ([9e97a11](https://github.com/typescript-eslint/typescript-eslint/commit/9e97a11ecd80be5c63c980bfe8d8e57400221cec))
+* **eslint-plugin:** [prefer-readonly] correct issue with anonymus functions ([#4974](https://github.com/typescript-eslint/typescript-eslint/issues/4974)) ([952e2f0](https://github.com/typescript-eslint/typescript-eslint/commit/952e2f068862dde089ec03d3eb5452d1ee3e9271)), closes [#2590](https://github.com/typescript-eslint/typescript-eslint/issues/2590)
+
+
+### Features
+
+* [4.7] support instantiation expressions ([#4938](https://github.com/typescript-eslint/typescript-eslint/issues/4938)) ([79fbc77](https://github.com/typescript-eslint/typescript-eslint/commit/79fbc7743ae5dce3190f8168776e0204755390ad))
+* [4.7] support optional variance annotation ([#4831](https://github.com/typescript-eslint/typescript-eslint/issues/4831)) ([7e7b24c](https://github.com/typescript-eslint/typescript-eslint/commit/7e7b24c196e6d968e48f97f46feae5e7027e22d2))
+* **typescript-estree:** `extends` constraints for `infer` ([#4830](https://github.com/typescript-eslint/typescript-eslint/issues/4830)) ([8cbbcc3](https://github.com/typescript-eslint/typescript-eslint/commit/8cbbcc3d317779e0dcba15d3835137f38383de34))
+
+
+
+
+
 # [5.25.0](https://github.com/typescript-eslint/typescript-eslint/compare/v5.24.0...v5.25.0) (2022-05-17)
 
 
diff --git a/jest.config.base.js b/jest.config.base.js
index 4470c1be07b9..b94573bf7196 100644
--- a/jest.config.base.js
+++ b/jest.config.base.js
@@ -3,17 +3,34 @@
 // @ts-check
 /** @type {import('@jest/types').Config.InitialOptions} */
 module.exports = {
-  collectCoverage: false,
+  collectCoverage: true,
   collectCoverageFrom: ['src/**/*.{js,jsx,ts,tsx}'],
-  coverageReporters: ['text-summary', 'lcov'],
-  moduleFileExtensions: ['ts', 'tsx', 'js', 'jsx', 'json', 'node'],
+  coverageReporters: ['lcov'],
+  moduleFileExtensions: [
+    'ts',
+    'tsx',
+    'mts',
+    'mtsx',
+    'js',
+    'jsx',
+    'mjs',
+    'mjsx',
+    'json',
+    'node',
+  ],
   resolver: '<rootDir>/../../tests/jest-resolver.js',
+  testRegex: ['./tests/.+\\.test\\.ts$', './tests/.+\\.spec\\.ts$'],
   transform: {
     '^.+\\.(t|j)sx?$': [
       '@swc/jest',
       {
         jsc: {
           target: 'es2019',
+          transform: {
+            react: {
+              runtime: 'automatic',
+            },
+          },
         },
       },
     ],
diff --git a/jest.preset.js b/jest.preset.js
deleted file mode 100644
index 3d08453c18d0..000000000000
--- a/jest.preset.js
+++ /dev/null
@@ -1,15 +0,0 @@
-// @ts-check
-
-/* eslint-disable import/no-extraneous-dependencies */
-/* eslint-disable @typescript-eslint/no-unsafe-assignment */
-
-'use strict';
-
-/** @type {import('@nrwl/jest/preset/jest-preset')} */
-const nxPreset = require('@nrwl/jest/preset');
-
-const { transform: _ignoredTsJestTransform, ...configToUse } = nxPreset;
-
-module.exports = {
-  ...configToUse,
-};
diff --git a/lerna.json b/lerna.json
index 92f35158ff3e..3ebfe1032e95 100644
--- a/lerna.json
+++ b/lerna.json
@@ -1,5 +1,5 @@
 {
-  "version": "5.25.0",
+  "version": "5.26.0",
   "npmClient": "yarn",
   "useWorkspaces": true,
   "stream": true
diff --git a/packages/ast-spec/CHANGELOG.md b/packages/ast-spec/CHANGELOG.md
index 56b71dfd61bd..7b5375ac92c8 100644
--- a/packages/ast-spec/CHANGELOG.md
+++ b/packages/ast-spec/CHANGELOG.md
@@ -3,6 +3,23 @@
 All notable changes to this project will be documented in this file.
 See [Conventional Commits](https://conventionalcommits.org) for commit guidelines.
 
+# [5.26.0](https://github.com/typescript-eslint/typescript-eslint/compare/v5.25.0...v5.26.0) (2022-05-23)
+
+
+### Bug Fixes
+
+* **ast-spec:** add `SpreadElement` to `ArrayExpression.elements` ([#5025](https://github.com/typescript-eslint/typescript-eslint/issues/5025)) ([9f3121b](https://github.com/typescript-eslint/typescript-eslint/commit/9f3121b228b9c066bff7a6011aecf269ac55f17c))
+
+
+### Features
+
+* [4.7] support instantiation expressions ([#4938](https://github.com/typescript-eslint/typescript-eslint/issues/4938)) ([79fbc77](https://github.com/typescript-eslint/typescript-eslint/commit/79fbc7743ae5dce3190f8168776e0204755390ad))
+* [4.7] support optional variance annotation ([#4831](https://github.com/typescript-eslint/typescript-eslint/issues/4831)) ([7e7b24c](https://github.com/typescript-eslint/typescript-eslint/commit/7e7b24c196e6d968e48f97f46feae5e7027e22d2))
+
+
+
+
+
 # [5.25.0](https://github.com/typescript-eslint/typescript-eslint/compare/v5.24.0...v5.25.0) (2022-05-17)
 
 **Note:** Version bump only for package @typescript-eslint/ast-spec
diff --git a/packages/ast-spec/jest.config.js b/packages/ast-spec/jest.config.js
index ac3b63608b7a..eeae64cb5dd4 100644
--- a/packages/ast-spec/jest.config.js
+++ b/packages/ast-spec/jest.config.js
@@ -4,10 +4,6 @@
 /** @type {import('@jest/types').Config.InitialOptions} */
 module.exports = {
   ...require('../../jest.config.base.js'),
-  testRegex: ['./tests/.+\\.test\\.ts$'],
   collectCoverage: false,
-  collectCoverageFrom: ['src/**/*.{js,jsx,ts,tsx}'],
-  moduleFileExtensions: ['ts', 'tsx', 'js', 'jsx', 'json', 'node'],
-  coverageReporters: ['text-summary', 'lcov'],
   setupFilesAfterEnv: ['./tests/util/setupJest.ts'],
 };
diff --git a/packages/ast-spec/package.json b/packages/ast-spec/package.json
index 1b605ffd02e8..cc762e151c85 100644
--- a/packages/ast-spec/package.json
+++ b/packages/ast-spec/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@typescript-eslint/ast-spec",
-  "version": "5.25.0",
+  "version": "5.26.0",
   "description": "TypeScript-ESTree AST spec",
   "private": true,
   "keywords": [
diff --git a/packages/ast-spec/src/ast-node-types.ts b/packages/ast-spec/src/ast-node-types.ts
index dec24662b22e..ff90dd1ee180 100644
--- a/packages/ast-spec/src/ast-node-types.ts
+++ b/packages/ast-spec/src/ast-node-types.ts
@@ -113,6 +113,7 @@ export enum AST_NODE_TYPES {
   TSExportKeyword = 'TSExportKeyword',
   TSExternalModuleReference = 'TSExternalModuleReference',
   TSFunctionType = 'TSFunctionType',
+  TSInstantiationExpression = 'TSInstantiationExpression',
   TSImportEqualsDeclaration = 'TSImportEqualsDeclaration',
   TSImportType = 'TSImportType',
   TSIndexedAccessType = 'TSIndexedAccessType',
diff --git a/packages/ast-spec/src/base/ClassBase.ts b/packages/ast-spec/src/base/ClassBase.ts
new file mode 100644
index 000000000000..4878cfc87b61
--- /dev/null
+++ b/packages/ast-spec/src/base/ClassBase.ts
@@ -0,0 +1,70 @@
+import type { Identifier } from '../expression/Identifier/spec';
+import type { ClassBody } from '../special/ClassBody/spec';
+import type { Decorator } from '../special/Decorator/spec';
+import type { TSClassImplements } from '../special/TSClassImplements/spec';
+import type { TSTypeParameterDeclaration } from '../special/TSTypeParameterDeclaration/spec';
+import type { TSTypeParameterInstantiation } from '../special/TSTypeParameterInstantiation/spec';
+import type { LeftHandSideExpression } from '../unions/LeftHandSideExpression';
+import type { BaseNode } from './BaseNode';
+
+export interface ClassBase extends BaseNode {
+  /**
+   * Whether the class is an abstract class.
+   * ```
+   * abstract class Foo {...}
+   * ```
+   * This is always `undefined` for `ClassExpression`.
+   */
+  // TODO(#5020) - make this `false` if it is not `abstract`
+  abstract?: boolean;
+  /**
+   * The class body.
+   */
+  body: ClassBody;
+  /**
+   * Whether the class has been `declare`d:
+   * ```
+   * declare class Foo {...}
+   * ```
+   * This is always `undefined` for `ClassExpression`.
+   */
+  // TODO(#5020) - make this `false` if it is not `declare`d
+  declare?: boolean;
+  /**
+   * The decorators declared for the class.
+   * This is `undefined` if there are no decorators.
+   * ```
+   * @deco
+   * class Foo {...}
+   * ```
+   * This is always `undefined` for `ClassExpression`.
+   */
+  // TODO(#5020) - make this an empty array if there are none declared
+  decorators?: Decorator[];
+  /**
+   * The class's name.
+   * - For a `ClassExpression` this may be `null` if the name is omitted.
+   * - For a `ClassDeclaration` this may be `null` if and only if the parent is
+   *   an `ExportDefaultDeclaration`.
+   */
+  id: Identifier | null;
+  /**
+   * The implemented interfaces for the class.
+   * This is `undefined` if there are no implemented interfaces.
+   */
+  implements?: TSClassImplements[];
+  /**
+   * The super class this class extends.
+   */
+  superClass: LeftHandSideExpression | null;
+  /**
+   * The generic type parameters passed to the superClass.
+   * This is `undefined` if there are no generic type parameters passed.
+   */
+  superTypeParameters?: TSTypeParameterInstantiation;
+  /**
+   * The generic type parameters declared for the class.
+   * This is `undefined` if there are no generic type parameters declared.
+   */
+  typeParameters?: TSTypeParameterDeclaration;
+}
diff --git a/packages/ast-spec/src/base/ClassDeclarationBase.ts b/packages/ast-spec/src/base/ClassDeclarationBase.ts
deleted file mode 100644
index f104b739b517..000000000000
--- a/packages/ast-spec/src/base/ClassDeclarationBase.ts
+++ /dev/null
@@ -1,20 +0,0 @@
-import type { Identifier } from '../expression/Identifier/spec';
-import type { ClassBody } from '../special/ClassBody/spec';
-import type { Decorator } from '../special/Decorator/spec';
-import type { TSClassImplements } from '../special/TSClassImplements/spec';
-import type { TSTypeParameterDeclaration } from '../special/TSTypeParameterDeclaration/spec';
-import type { TSTypeParameterInstantiation } from '../special/TSTypeParameterInstantiation/spec';
-import type { LeftHandSideExpression } from '../unions/LeftHandSideExpression';
-import type { BaseNode } from './BaseNode';
-
-export interface ClassDeclarationBase extends BaseNode {
-  typeParameters?: TSTypeParameterDeclaration;
-  superTypeParameters?: TSTypeParameterInstantiation;
-  id: Identifier | null;
-  body: ClassBody;
-  superClass: LeftHandSideExpression | null;
-  implements?: TSClassImplements[];
-  abstract?: boolean;
-  declare?: boolean;
-  decorators?: Decorator[];
-}
diff --git a/packages/ast-spec/src/base/FunctionBase.ts b/packages/ast-spec/src/base/FunctionBase.ts
new file mode 100644
index 000000000000..56446bc78ba9
--- /dev/null
+++ b/packages/ast-spec/src/base/FunctionBase.ts
@@ -0,0 +1,74 @@
+import type { Identifier } from '../expression/Identifier/spec';
+import type { TSTypeAnnotation } from '../special/TSTypeAnnotation/spec';
+import type { TSTypeParameterDeclaration } from '../special/TSTypeParameterDeclaration/spec';
+import type { BlockStatement } from '../statement/BlockStatement/spec';
+import type { Expression } from '../unions/Expression';
+import type { Parameter } from '../unions/Parameter';
+import type { BaseNode } from './BaseNode';
+
+export interface FunctionBase extends BaseNode {
+  /**
+   * Whether the function is async:
+   * ```
+   * async function foo(...) {...}
+   * const x = async function (...) {...}
+   * const x = async (...) => {...}
+   * ```
+   */
+  async: boolean;
+  /**
+   * The body of the function.
+   * - For an `ArrowFunctionExpression` this may be an `Expression` or `BlockStatement`.
+   * - For a `FunctionDeclaration` or `FunctionExpression` this is always a `BlockStatement.
+   * - For a `TSDeclareFunction` this is always `undefined`.
+   * - For a `TSEmptyBodyFunctionExpression` this is always `null`.
+   */
+  body?: BlockStatement | Expression | null;
+  /**
+   * This is only `true` if and only if the node is a `TSDeclareFunction` and it has `declare`:
+   * ```
+   * declare function foo(...) {...}
+   * ```
+   */
+  // TODO(#5020) - make this always `false` if it is not `declare`d instead of `undefined`
+  declare?: boolean;
+  /**
+   * This is only ever `true` if and only the node is an `ArrowFunctionExpression` and the body
+   * is an expression:
+   * ```
+   * (() => 1)
+   * ```
+   */
+  expression: boolean;
+  /**
+   * Whether the function is a generator function:
+   * ```
+   * function *foo(...) {...}
+   * const x = function *(...) {...}
+   * ```
+   * This is always `false` for arrow functions as they cannot be generators.
+   */
+  generator: boolean;
+  /**
+   * The function's name.
+   * - For an `ArrowFunctionExpression` this is always `null`.
+   * - For a `FunctionExpression` this may be `null` if the name is omitted.
+   * - For a `FunctionDeclaration` or `TSDeclareFunction` this may be `null` if
+   *   and only if the parent is an `ExportDefaultDeclaration`.
+   */
+  id: Identifier | null;
+  /**
+   * The list of parameters declared for the function.
+   */
+  params: Parameter[];
+  /**
+   * The return type annotation for the function.
+   * This is `undefined` if there is no return type declared.
+   */
+  returnType?: TSTypeAnnotation;
+  /**
+   * The generic type parameter declaration for the function.
+   * This is `undefined` if there are no generic type parameters declared.
+   */
+  typeParameters?: TSTypeParameterDeclaration;
+}
diff --git a/packages/ast-spec/src/base/FunctionDeclarationBase.ts b/packages/ast-spec/src/base/FunctionDeclarationBase.ts
deleted file mode 100644
index 50b7aa97bf2f..000000000000
--- a/packages/ast-spec/src/base/FunctionDeclarationBase.ts
+++ /dev/null
@@ -1,18 +0,0 @@
-import type { Identifier } from '../expression/Identifier/spec';
-import type { TSTypeAnnotation } from '../special/TSTypeAnnotation/spec';
-import type { TSTypeParameterDeclaration } from '../special/TSTypeParameterDeclaration/spec';
-import type { BlockStatement } from '../statement/BlockStatement/spec';
-import type { Parameter } from '../unions/Parameter';
-import type { BaseNode } from './BaseNode';
-
-export interface FunctionDeclarationBase extends BaseNode {
-  id: Identifier | null;
-  generator: boolean;
-  expression: boolean;
-  async: boolean;
-  params: Parameter[];
-  body?: BlockStatement | null;
-  returnType?: TSTypeAnnotation;
-  typeParameters?: TSTypeParameterDeclaration;
-  declare?: boolean;
-}
diff --git a/packages/ast-spec/src/base/TSHeritageBase.ts b/packages/ast-spec/src/base/TSHeritageBase.ts
index 5c20542e4f92..683600ec01d3 100644
--- a/packages/ast-spec/src/base/TSHeritageBase.ts
+++ b/packages/ast-spec/src/base/TSHeritageBase.ts
@@ -3,7 +3,7 @@ import type { Expression } from '../unions/Expression';
 import type { BaseNode } from './BaseNode';
 
 export interface TSHeritageBase extends BaseNode {
-  // TODO(error handling) - this should be restricted to MemberExpression | Identifier
+  // TODO(#1852) - this should be restricted to MemberExpression | Identifier
   expression: Expression;
   typeParameters?: TSTypeParameterInstantiation;
 }
diff --git a/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/_error_/no-body/fixture.ts b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/_error_/missing-body/fixture.ts
similarity index 100%
rename from packages/ast-spec/src/declaration/ClassDeclaration/fixtures/_error_/no-body/fixture.ts
rename to packages/ast-spec/src/declaration/ClassDeclaration/fixtures/_error_/missing-body/fixture.ts
diff --git a/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/_error_/missing-body/snapshots/1-TSESTree-Error.shot b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/_error_/missing-body/snapshots/1-TSESTree-Error.shot
new file mode 100644
index 000000000000..c17328b32e82
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/_error_/missing-body/snapshots/1-TSESTree-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ClassDeclaration _error_ missing-body TSESTree - Error 1`] = `[TSError: '{' expected.]`;
diff --git a/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/_error_/missing-body/snapshots/2-Babel-Error.shot b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/_error_/missing-body/snapshots/2-Babel-Error.shot
new file mode 100644
index 000000000000..4f8ef959d9ba
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/_error_/missing-body/snapshots/2-Babel-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ClassDeclaration _error_ missing-body Babel - Error 1`] = `[SyntaxError: Unexpected token, expected "{" (1:9)]`;
diff --git a/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/_error_/missing-body/snapshots/3-Alignment-Error.shot b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/_error_/missing-body/snapshots/3-Alignment-Error.shot
new file mode 100644
index 000000000000..18e4442401e0
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/_error_/missing-body/snapshots/3-Alignment-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ClassDeclaration _error_ missing-body Error Alignment 1`] = `"Both errored"`;
diff --git a/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/_error_/missing-extends-type-param/fixture.ts b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/_error_/missing-extends-type-param/fixture.ts
new file mode 100644
index 000000000000..83ffb99a72bd
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/_error_/missing-extends-type-param/fixture.ts
@@ -0,0 +1 @@
+class C extends D<> {}
diff --git a/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/_error_/missing-extends-type-param/snapshots/1-TSESTree-Error.shot b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/_error_/missing-extends-type-param/snapshots/1-TSESTree-Error.shot
new file mode 100644
index 000000000000..4f99d71eb953
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/_error_/missing-extends-type-param/snapshots/1-TSESTree-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ClassDeclaration _error_ missing-extends-type-param TSESTree - Error 1`] = `"NO ERROR"`;
diff --git a/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/_error_/missing-extends-type-param/snapshots/2-Babel-Error.shot b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/_error_/missing-extends-type-param/snapshots/2-Babel-Error.shot
new file mode 100644
index 000000000000..f84357321316
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/_error_/missing-extends-type-param/snapshots/2-Babel-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ClassDeclaration _error_ missing-extends-type-param Babel - Error 1`] = `[SyntaxError: Type argument list cannot be empty. (1:17)]`;
diff --git a/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/_error_/missing-extends-type-param/snapshots/3-Alignment-Error.shot b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/_error_/missing-extends-type-param/snapshots/3-Alignment-Error.shot
new file mode 100644
index 000000000000..35683b841219
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/_error_/missing-extends-type-param/snapshots/3-Alignment-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ClassDeclaration _error_ missing-extends-type-param Error Alignment 1`] = `"Babel errored but TSESTree didn't"`;
diff --git a/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/_error_/missing-type-param/fixture.ts b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/_error_/missing-type-param/fixture.ts
new file mode 100644
index 000000000000..4f3d75967f9b
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/_error_/missing-type-param/fixture.ts
@@ -0,0 +1 @@
+class C<> {}
diff --git a/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/_error_/missing-type-param/snapshots/1-TSESTree-Error.shot b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/_error_/missing-type-param/snapshots/1-TSESTree-Error.shot
new file mode 100644
index 000000000000..9682f9c4373e
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/_error_/missing-type-param/snapshots/1-TSESTree-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ClassDeclaration _error_ missing-type-param TSESTree - Error 1`] = `"NO ERROR"`;
diff --git a/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/_error_/missing-type-param/snapshots/2-Babel-Error.shot b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/_error_/missing-type-param/snapshots/2-Babel-Error.shot
new file mode 100644
index 000000000000..a14c3c54cac7
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/_error_/missing-type-param/snapshots/2-Babel-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ClassDeclaration _error_ missing-type-param Babel - Error 1`] = `[SyntaxError: Type parameter list cannot be empty. (1:7)]`;
diff --git a/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/_error_/missing-type-param/snapshots/3-Alignment-Error.shot b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/_error_/missing-type-param/snapshots/3-Alignment-Error.shot
new file mode 100644
index 000000000000..49567ea7a7b5
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/_error_/missing-type-param/snapshots/3-Alignment-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ClassDeclaration _error_ missing-type-param Error Alignment 1`] = `"Babel errored but TSESTree didn't"`;
diff --git a/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/_error_/no-body/snapshots/1-TSESTree-Error.shot b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/_error_/no-body/snapshots/1-TSESTree-Error.shot
deleted file mode 100644
index 305258435809..000000000000
--- a/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/_error_/no-body/snapshots/1-TSESTree-Error.shot
+++ /dev/null
@@ -1,3 +0,0 @@
-// Jest Snapshot v1, https://goo.gl/fbAQLP
-
-exports[`AST Fixtures declaration ClassDeclaration _error_ no-body TSESTree - Error 1`] = `[TSError: '{' expected.]`;
diff --git a/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/_error_/no-body/snapshots/2-Babel-Error.shot b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/_error_/no-body/snapshots/2-Babel-Error.shot
deleted file mode 100644
index e72c371e8425..000000000000
--- a/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/_error_/no-body/snapshots/2-Babel-Error.shot
+++ /dev/null
@@ -1,3 +0,0 @@
-// Jest Snapshot v1, https://goo.gl/fbAQLP
-
-exports[`AST Fixtures declaration ClassDeclaration _error_ no-body Babel - Error 1`] = `[SyntaxError: Unexpected token, expected "{" (1:9)]`;
diff --git a/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/_error_/no-body/snapshots/3-Alignment-Error.shot b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/_error_/no-body/snapshots/3-Alignment-Error.shot
deleted file mode 100644
index b69460232224..000000000000
--- a/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/_error_/no-body/snapshots/3-Alignment-Error.shot
+++ /dev/null
@@ -1,3 +0,0 @@
-// Jest Snapshot v1, https://goo.gl/fbAQLP
-
-exports[`AST Fixtures declaration ClassDeclaration _error_ no-body Error Alignment 1`] = `"Both errored"`;
diff --git a/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/_error_/non-identifier-type-param/fixture.ts b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/_error_/non-identifier-type-param/fixture.ts
new file mode 100644
index 000000000000..383479818e60
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/_error_/non-identifier-type-param/fixture.ts
@@ -0,0 +1 @@
+class C<1> {}
diff --git a/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/_error_/non-identifier-type-param/snapshots/1-TSESTree-Error.shot b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/_error_/non-identifier-type-param/snapshots/1-TSESTree-Error.shot
new file mode 100644
index 000000000000..0be64ad34736
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/_error_/non-identifier-type-param/snapshots/1-TSESTree-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ClassDeclaration _error_ non-identifier-type-param TSESTree - Error 1`] = `[TSError: Type parameter declaration expected.]`;
diff --git a/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/_error_/non-identifier-type-param/snapshots/2-Babel-Error.shot b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/_error_/non-identifier-type-param/snapshots/2-Babel-Error.shot
new file mode 100644
index 000000000000..6ef9a4c481a7
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/_error_/non-identifier-type-param/snapshots/2-Babel-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ClassDeclaration _error_ non-identifier-type-param Babel - Error 1`] = `[SyntaxError: Unexpected token (1:8)]`;
diff --git a/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/_error_/non-identifier-type-param/snapshots/3-Alignment-Error.shot b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/_error_/non-identifier-type-param/snapshots/3-Alignment-Error.shot
new file mode 100644
index 000000000000..98c58289073e
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/_error_/non-identifier-type-param/snapshots/3-Alignment-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ClassDeclaration _error_ non-identifier-type-param Error Alignment 1`] = `"Both errored"`;
diff --git a/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/decoratorMany/fixture.ts b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/decorator-many/fixture.ts
similarity index 100%
rename from packages/ast-spec/src/declaration/ClassDeclaration/fixtures/decoratorMany/fixture.ts
rename to packages/ast-spec/src/declaration/ClassDeclaration/fixtures/decorator-many/fixture.ts
diff --git a/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/decoratorMany/snapshots/1-TSESTree-AST.shot b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/decorator-many/snapshots/1-TSESTree-AST.shot
similarity index 95%
rename from packages/ast-spec/src/declaration/ClassDeclaration/fixtures/decoratorMany/snapshots/1-TSESTree-AST.shot
rename to packages/ast-spec/src/declaration/ClassDeclaration/fixtures/decorator-many/snapshots/1-TSESTree-AST.shot
index ab7726fcd526..7f37d13c4882 100644
--- a/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/decoratorMany/snapshots/1-TSESTree-AST.shot
+++ b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/decorator-many/snapshots/1-TSESTree-AST.shot
@@ -1,6 +1,6 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
-exports[`AST Fixtures declaration ClassDeclaration decoratorMany TSESTree - AST 1`] = `
+exports[`AST Fixtures declaration ClassDeclaration decorator-many TSESTree - AST 1`] = `
 Program {
   type: "Program",
   body: Array [
diff --git a/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/decoratorMany/snapshots/2-TSESTree-Tokens.shot b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/decorator-many/snapshots/2-TSESTree-Tokens.shot
similarity index 94%
rename from packages/ast-spec/src/declaration/ClassDeclaration/fixtures/decoratorMany/snapshots/2-TSESTree-Tokens.shot
rename to packages/ast-spec/src/declaration/ClassDeclaration/fixtures/decorator-many/snapshots/2-TSESTree-Tokens.shot
index f406c8123352..5f64c50c3bdc 100644
--- a/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/decoratorMany/snapshots/2-TSESTree-Tokens.shot
+++ b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/decorator-many/snapshots/2-TSESTree-Tokens.shot
@@ -1,6 +1,6 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
-exports[`AST Fixtures declaration ClassDeclaration decoratorMany TSESTree - Tokens 1`] = `
+exports[`AST Fixtures declaration ClassDeclaration decorator-many TSESTree - Tokens 1`] = `
 Array [
   Punctuator {
     type: "Punctuator",
diff --git a/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/decoratorMany/snapshots/3-Babel-AST.shot b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/decorator-many/snapshots/3-Babel-AST.shot
similarity index 95%
rename from packages/ast-spec/src/declaration/ClassDeclaration/fixtures/decoratorMany/snapshots/3-Babel-AST.shot
rename to packages/ast-spec/src/declaration/ClassDeclaration/fixtures/decorator-many/snapshots/3-Babel-AST.shot
index 60af58e326d3..3c94fd556d00 100644
--- a/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/decoratorMany/snapshots/3-Babel-AST.shot
+++ b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/decorator-many/snapshots/3-Babel-AST.shot
@@ -1,6 +1,6 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
-exports[`AST Fixtures declaration ClassDeclaration decoratorMany Babel - AST 1`] = `
+exports[`AST Fixtures declaration ClassDeclaration decorator-many Babel - AST 1`] = `
 Program {
   type: "Program",
   body: Array [
diff --git a/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/decoratorMany/snapshots/4-Babel-Tokens.shot b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/decorator-many/snapshots/4-Babel-Tokens.shot
similarity index 94%
rename from packages/ast-spec/src/declaration/ClassDeclaration/fixtures/decoratorMany/snapshots/4-Babel-Tokens.shot
rename to packages/ast-spec/src/declaration/ClassDeclaration/fixtures/decorator-many/snapshots/4-Babel-Tokens.shot
index 888d2f213d3f..e7d7dba3776b 100644
--- a/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/decoratorMany/snapshots/4-Babel-Tokens.shot
+++ b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/decorator-many/snapshots/4-Babel-Tokens.shot
@@ -1,6 +1,6 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
-exports[`AST Fixtures declaration ClassDeclaration decoratorMany Babel - Tokens 1`] = `
+exports[`AST Fixtures declaration ClassDeclaration decorator-many Babel - Tokens 1`] = `
 Array [
   Punctuator {
     type: "Punctuator",
diff --git a/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/decorator-many/snapshots/5-AST-Alignment-AST.shot b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/decorator-many/snapshots/5-AST-Alignment-AST.shot
new file mode 100644
index 000000000000..751a6cc951f0
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/decorator-many/snapshots/5-AST-Alignment-AST.shot
@@ -0,0 +1,6 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ClassDeclaration decorator-many AST Alignment - AST 1`] = `
+"Snapshot Diff:
+Compared values have no visual difference."
+`;
diff --git a/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/decorator-many/snapshots/6-AST-Alignment-Tokens.shot b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/decorator-many/snapshots/6-AST-Alignment-Tokens.shot
new file mode 100644
index 000000000000..338a8838194e
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/decorator-many/snapshots/6-AST-Alignment-Tokens.shot
@@ -0,0 +1,6 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ClassDeclaration decorator-many AST Alignment - Token 1`] = `
+"Snapshot Diff:
+Compared values have no visual difference."
+`;
diff --git a/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/decoratorOne/fixture.ts b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/decorator-one/fixture.ts
similarity index 100%
rename from packages/ast-spec/src/declaration/ClassDeclaration/fixtures/decoratorOne/fixture.ts
rename to packages/ast-spec/src/declaration/ClassDeclaration/fixtures/decorator-one/fixture.ts
diff --git a/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/decoratorOne/snapshots/1-TSESTree-AST.shot b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/decorator-one/snapshots/1-TSESTree-AST.shot
similarity index 93%
rename from packages/ast-spec/src/declaration/ClassDeclaration/fixtures/decoratorOne/snapshots/1-TSESTree-AST.shot
rename to packages/ast-spec/src/declaration/ClassDeclaration/fixtures/decorator-one/snapshots/1-TSESTree-AST.shot
index f0550dcabbe8..aba5fc9308df 100644
--- a/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/decoratorOne/snapshots/1-TSESTree-AST.shot
+++ b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/decorator-one/snapshots/1-TSESTree-AST.shot
@@ -1,6 +1,6 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
-exports[`AST Fixtures declaration ClassDeclaration decoratorOne TSESTree - AST 1`] = `
+exports[`AST Fixtures declaration ClassDeclaration decorator-one TSESTree - AST 1`] = `
 Program {
   type: "Program",
   body: Array [
diff --git a/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/decoratorOne/snapshots/2-TSESTree-Tokens.shot b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/decorator-one/snapshots/2-TSESTree-Tokens.shot
similarity index 92%
rename from packages/ast-spec/src/declaration/ClassDeclaration/fixtures/decoratorOne/snapshots/2-TSESTree-Tokens.shot
rename to packages/ast-spec/src/declaration/ClassDeclaration/fixtures/decorator-one/snapshots/2-TSESTree-Tokens.shot
index 7354a4e9bfed..7d75dd277906 100644
--- a/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/decoratorOne/snapshots/2-TSESTree-Tokens.shot
+++ b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/decorator-one/snapshots/2-TSESTree-Tokens.shot
@@ -1,6 +1,6 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
-exports[`AST Fixtures declaration ClassDeclaration decoratorOne TSESTree - Tokens 1`] = `
+exports[`AST Fixtures declaration ClassDeclaration decorator-one TSESTree - Tokens 1`] = `
 Array [
   Punctuator {
     type: "Punctuator",
diff --git a/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/decoratorOne/snapshots/3-Babel-AST.shot b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/decorator-one/snapshots/3-Babel-AST.shot
similarity index 94%
rename from packages/ast-spec/src/declaration/ClassDeclaration/fixtures/decoratorOne/snapshots/3-Babel-AST.shot
rename to packages/ast-spec/src/declaration/ClassDeclaration/fixtures/decorator-one/snapshots/3-Babel-AST.shot
index f2e4581ba588..9f91cb39e807 100644
--- a/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/decoratorOne/snapshots/3-Babel-AST.shot
+++ b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/decorator-one/snapshots/3-Babel-AST.shot
@@ -1,6 +1,6 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
-exports[`AST Fixtures declaration ClassDeclaration decoratorOne Babel - AST 1`] = `
+exports[`AST Fixtures declaration ClassDeclaration decorator-one Babel - AST 1`] = `
 Program {
   type: "Program",
   body: Array [
diff --git a/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/decoratorOne/snapshots/4-Babel-Tokens.shot b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/decorator-one/snapshots/4-Babel-Tokens.shot
similarity index 92%
rename from packages/ast-spec/src/declaration/ClassDeclaration/fixtures/decoratorOne/snapshots/4-Babel-Tokens.shot
rename to packages/ast-spec/src/declaration/ClassDeclaration/fixtures/decorator-one/snapshots/4-Babel-Tokens.shot
index eb1816cba73b..3b6aa60b33d6 100644
--- a/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/decoratorOne/snapshots/4-Babel-Tokens.shot
+++ b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/decorator-one/snapshots/4-Babel-Tokens.shot
@@ -1,6 +1,6 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
-exports[`AST Fixtures declaration ClassDeclaration decoratorOne Babel - Tokens 1`] = `
+exports[`AST Fixtures declaration ClassDeclaration decorator-one Babel - Tokens 1`] = `
 Array [
   Punctuator {
     type: "Punctuator",
diff --git a/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/decoratorMany/snapshots/5-AST-Alignment-AST.shot b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/decorator-one/snapshots/5-AST-Alignment-AST.shot
similarity index 68%
rename from packages/ast-spec/src/declaration/ClassDeclaration/fixtures/decoratorMany/snapshots/5-AST-Alignment-AST.shot
rename to packages/ast-spec/src/declaration/ClassDeclaration/fixtures/decorator-one/snapshots/5-AST-Alignment-AST.shot
index 97881c1404c3..503bd4f5ad82 100644
--- a/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/decoratorMany/snapshots/5-AST-Alignment-AST.shot
+++ b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/decorator-one/snapshots/5-AST-Alignment-AST.shot
@@ -1,6 +1,6 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
-exports[`AST Fixtures declaration ClassDeclaration decoratorMany AST Alignment - AST 1`] = `
+exports[`AST Fixtures declaration ClassDeclaration decorator-one AST Alignment - AST 1`] = `
 "Snapshot Diff:
 Compared values have no visual difference."
 `;
diff --git a/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/decoratorMany/snapshots/6-AST-Alignment-Tokens.shot b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/decorator-one/snapshots/6-AST-Alignment-Tokens.shot
similarity index 68%
rename from packages/ast-spec/src/declaration/ClassDeclaration/fixtures/decoratorMany/snapshots/6-AST-Alignment-Tokens.shot
rename to packages/ast-spec/src/declaration/ClassDeclaration/fixtures/decorator-one/snapshots/6-AST-Alignment-Tokens.shot
index e57e9fa7313b..1ab8923d733f 100644
--- a/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/decoratorMany/snapshots/6-AST-Alignment-Tokens.shot
+++ b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/decorator-one/snapshots/6-AST-Alignment-Tokens.shot
@@ -1,6 +1,6 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
-exports[`AST Fixtures declaration ClassDeclaration decoratorMany AST Alignment - Token 1`] = `
+exports[`AST Fixtures declaration ClassDeclaration decorator-one AST Alignment - Token 1`] = `
 "Snapshot Diff:
 Compared values have no visual difference."
 `;
diff --git a/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/extends-type-parameters/fixture.ts b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/extends-type-param/fixture.ts
similarity index 100%
rename from packages/ast-spec/src/declaration/ClassDeclaration/fixtures/extends-type-parameters/fixture.ts
rename to packages/ast-spec/src/declaration/ClassDeclaration/fixtures/extends-type-param/fixture.ts
diff --git a/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/extends-type-parameters/snapshots/1-TSESTree-AST.shot b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/extends-type-param/snapshots/1-TSESTree-AST.shot
similarity index 97%
rename from packages/ast-spec/src/declaration/ClassDeclaration/fixtures/extends-type-parameters/snapshots/1-TSESTree-AST.shot
rename to packages/ast-spec/src/declaration/ClassDeclaration/fixtures/extends-type-param/snapshots/1-TSESTree-AST.shot
index da9fc3ba5ca5..43fbb02d6c00 100644
--- a/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/extends-type-parameters/snapshots/1-TSESTree-AST.shot
+++ b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/extends-type-param/snapshots/1-TSESTree-AST.shot
@@ -1,6 +1,6 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
-exports[`AST Fixtures declaration ClassDeclaration extends-type-parameters TSESTree - AST 1`] = `
+exports[`AST Fixtures declaration ClassDeclaration extends-type-param TSESTree - AST 1`] = `
 Program {
   type: "Program",
   body: Array [
diff --git a/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/extends-type-parameters/snapshots/2-TSESTree-Tokens.shot b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/extends-type-param/snapshots/2-TSESTree-Tokens.shot
similarity index 97%
rename from packages/ast-spec/src/declaration/ClassDeclaration/fixtures/extends-type-parameters/snapshots/2-TSESTree-Tokens.shot
rename to packages/ast-spec/src/declaration/ClassDeclaration/fixtures/extends-type-param/snapshots/2-TSESTree-Tokens.shot
index 3eb2b515a24e..c0ea9a808468 100644
--- a/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/extends-type-parameters/snapshots/2-TSESTree-Tokens.shot
+++ b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/extends-type-param/snapshots/2-TSESTree-Tokens.shot
@@ -1,6 +1,6 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
-exports[`AST Fixtures declaration ClassDeclaration extends-type-parameters TSESTree - Tokens 1`] = `
+exports[`AST Fixtures declaration ClassDeclaration extends-type-param TSESTree - Tokens 1`] = `
 Array [
   Keyword {
     type: "Keyword",
diff --git a/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/extends-type-parameters/snapshots/3-Babel-AST.shot b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/extends-type-param/snapshots/3-Babel-AST.shot
similarity index 98%
rename from packages/ast-spec/src/declaration/ClassDeclaration/fixtures/extends-type-parameters/snapshots/3-Babel-AST.shot
rename to packages/ast-spec/src/declaration/ClassDeclaration/fixtures/extends-type-param/snapshots/3-Babel-AST.shot
index 8f9634b6629e..2071afa4c8e0 100644
--- a/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/extends-type-parameters/snapshots/3-Babel-AST.shot
+++ b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/extends-type-param/snapshots/3-Babel-AST.shot
@@ -1,6 +1,6 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
-exports[`AST Fixtures declaration ClassDeclaration extends-type-parameters Babel - AST 1`] = `
+exports[`AST Fixtures declaration ClassDeclaration extends-type-param Babel - AST 1`] = `
 Program {
   type: "Program",
   body: Array [
diff --git a/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/extends-type-parameters/snapshots/4-Babel-Tokens.shot b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/extends-type-param/snapshots/4-Babel-Tokens.shot
similarity index 98%
rename from packages/ast-spec/src/declaration/ClassDeclaration/fixtures/extends-type-parameters/snapshots/4-Babel-Tokens.shot
rename to packages/ast-spec/src/declaration/ClassDeclaration/fixtures/extends-type-param/snapshots/4-Babel-Tokens.shot
index db93259e13a5..a19207090a5f 100644
--- a/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/extends-type-parameters/snapshots/4-Babel-Tokens.shot
+++ b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/extends-type-param/snapshots/4-Babel-Tokens.shot
@@ -1,6 +1,6 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
-exports[`AST Fixtures declaration ClassDeclaration extends-type-parameters Babel - Tokens 1`] = `
+exports[`AST Fixtures declaration ClassDeclaration extends-type-param Babel - Tokens 1`] = `
 Array [
   Keyword {
     type: "Keyword",
diff --git a/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/extends-type-parameters/snapshots/5-AST-Alignment-AST.shot b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/extends-type-param/snapshots/5-AST-Alignment-AST.shot
similarity index 81%
rename from packages/ast-spec/src/declaration/ClassDeclaration/fixtures/extends-type-parameters/snapshots/5-AST-Alignment-AST.shot
rename to packages/ast-spec/src/declaration/ClassDeclaration/fixtures/extends-type-param/snapshots/5-AST-Alignment-AST.shot
index 17f60ddc36a5..d7a16a19520a 100644
--- a/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/extends-type-parameters/snapshots/5-AST-Alignment-AST.shot
+++ b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/extends-type-param/snapshots/5-AST-Alignment-AST.shot
@@ -1,6 +1,6 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
-exports[`AST Fixtures declaration ClassDeclaration extends-type-parameters AST Alignment - AST 1`] = `
+exports[`AST Fixtures declaration ClassDeclaration extends-type-param AST Alignment - AST 1`] = `
 "Snapshot Diff:
 Compared values have no visual difference."
 `;
diff --git a/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/extends-type-parameters/snapshots/6-AST-Alignment-Tokens.shot b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/extends-type-param/snapshots/6-AST-Alignment-Tokens.shot
similarity index 80%
rename from packages/ast-spec/src/declaration/ClassDeclaration/fixtures/extends-type-parameters/snapshots/6-AST-Alignment-Tokens.shot
rename to packages/ast-spec/src/declaration/ClassDeclaration/fixtures/extends-type-param/snapshots/6-AST-Alignment-Tokens.shot
index 8c6277e35df2..e231ba6210a9 100644
--- a/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/extends-type-parameters/snapshots/6-AST-Alignment-Tokens.shot
+++ b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/extends-type-param/snapshots/6-AST-Alignment-Tokens.shot
@@ -1,6 +1,6 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
-exports[`AST Fixtures declaration ClassDeclaration extends-type-parameters AST Alignment - Token 1`] = `
+exports[`AST Fixtures declaration ClassDeclaration extends-type-param AST Alignment - Token 1`] = `
 "Snapshot Diff:
 Compared values have no visual difference."
 `;
diff --git a/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/type-parameters/fixture.ts b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/type-param/fixture.ts
similarity index 100%
rename from packages/ast-spec/src/declaration/ClassDeclaration/fixtures/type-parameters/fixture.ts
rename to packages/ast-spec/src/declaration/ClassDeclaration/fixtures/type-param/fixture.ts
diff --git a/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/type-parameters/snapshots/1-TSESTree-AST.shot b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/type-param/snapshots/1-TSESTree-AST.shot
similarity index 92%
rename from packages/ast-spec/src/declaration/ClassDeclaration/fixtures/type-parameters/snapshots/1-TSESTree-AST.shot
rename to packages/ast-spec/src/declaration/ClassDeclaration/fixtures/type-param/snapshots/1-TSESTree-AST.shot
index 0b476f5584ed..13f2fe48ba0d 100644
--- a/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/type-parameters/snapshots/1-TSESTree-AST.shot
+++ b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/type-param/snapshots/1-TSESTree-AST.shot
@@ -1,6 +1,6 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
-exports[`AST Fixtures declaration ClassDeclaration type-parameters TSESTree - AST 1`] = `
+exports[`AST Fixtures declaration ClassDeclaration type-param TSESTree - AST 1`] = `
 Program {
   type: "Program",
   body: Array [
@@ -32,6 +32,7 @@ Program {
         params: Array [
           TSTypeParameter {
             type: "TSTypeParameter",
+            in: false,
             name: Identifier {
               type: "Identifier",
               name: "T",
@@ -42,6 +43,7 @@ Program {
                 end: { column: 11, line: 1 },
               },
             },
+            out: false,
 
             range: [10, 11],
             loc: {
diff --git a/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/type-parameters/snapshots/2-TSESTree-Tokens.shot b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/type-param/snapshots/2-TSESTree-Tokens.shot
similarity index 93%
rename from packages/ast-spec/src/declaration/ClassDeclaration/fixtures/type-parameters/snapshots/2-TSESTree-Tokens.shot
rename to packages/ast-spec/src/declaration/ClassDeclaration/fixtures/type-param/snapshots/2-TSESTree-Tokens.shot
index 7afa2b8839ba..4b814b828291 100644
--- a/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/type-parameters/snapshots/2-TSESTree-Tokens.shot
+++ b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/type-param/snapshots/2-TSESTree-Tokens.shot
@@ -1,6 +1,6 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
-exports[`AST Fixtures declaration ClassDeclaration type-parameters TSESTree - Tokens 1`] = `
+exports[`AST Fixtures declaration ClassDeclaration type-param TSESTree - Tokens 1`] = `
 Array [
   Keyword {
     type: "Keyword",
diff --git a/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/type-parameters/snapshots/3-Babel-AST.shot b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/type-param/snapshots/3-Babel-AST.shot
similarity index 94%
rename from packages/ast-spec/src/declaration/ClassDeclaration/fixtures/type-parameters/snapshots/3-Babel-AST.shot
rename to packages/ast-spec/src/declaration/ClassDeclaration/fixtures/type-param/snapshots/3-Babel-AST.shot
index de9ab22cc6b9..288661b13116 100644
--- a/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/type-parameters/snapshots/3-Babel-AST.shot
+++ b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/type-param/snapshots/3-Babel-AST.shot
@@ -1,6 +1,6 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
-exports[`AST Fixtures declaration ClassDeclaration type-parameters Babel - AST 1`] = `
+exports[`AST Fixtures declaration ClassDeclaration type-param Babel - AST 1`] = `
 Program {
   type: "Program",
   body: Array [
diff --git a/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/type-parameters/snapshots/4-Babel-Tokens.shot b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/type-param/snapshots/4-Babel-Tokens.shot
similarity index 93%
rename from packages/ast-spec/src/declaration/ClassDeclaration/fixtures/type-parameters/snapshots/4-Babel-Tokens.shot
rename to packages/ast-spec/src/declaration/ClassDeclaration/fixtures/type-param/snapshots/4-Babel-Tokens.shot
index 89bca663a6db..27db70bb89e0 100644
--- a/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/type-parameters/snapshots/4-Babel-Tokens.shot
+++ b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/type-param/snapshots/4-Babel-Tokens.shot
@@ -1,6 +1,6 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
-exports[`AST Fixtures declaration ClassDeclaration type-parameters Babel - Tokens 1`] = `
+exports[`AST Fixtures declaration ClassDeclaration type-param Babel - Tokens 1`] = `
 Array [
   Keyword {
     type: "Keyword",
diff --git a/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/type-parameters/snapshots/5-AST-Alignment-AST.shot b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/type-param/snapshots/5-AST-Alignment-AST.shot
similarity index 92%
rename from packages/ast-spec/src/declaration/ClassDeclaration/fixtures/type-parameters/snapshots/5-AST-Alignment-AST.shot
rename to packages/ast-spec/src/declaration/ClassDeclaration/fixtures/type-param/snapshots/5-AST-Alignment-AST.shot
index f3b75ecbb25a..0ee9dbba0359 100644
--- a/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/type-parameters/snapshots/5-AST-Alignment-AST.shot
+++ b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/type-param/snapshots/5-AST-Alignment-AST.shot
@@ -1,6 +1,6 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
-exports[`AST Fixtures declaration ClassDeclaration type-parameters AST Alignment - AST 1`] = `
+exports[`AST Fixtures declaration ClassDeclaration type-param AST Alignment - AST 1`] = `
 "Snapshot Diff:
 - TSESTree
 + Babel
@@ -36,6 +36,7 @@ exports[`AST Fixtures declaration ClassDeclaration type-parameters AST Alignment
           params: Array [
             TSTypeParameter {
               type: 'TSTypeParameter',
+-             in: false,
 -             name: Identifier {
 -               type: 'Identifier',
 -               name: 'T',
@@ -46,6 +47,7 @@ exports[`AST Fixtures declaration ClassDeclaration type-parameters AST Alignment
 -                 end: { column: 11, line: 1 },
 -               },
 -             },
+-             out: false,
 +             name: 'T',
 
               range: [10, 11],
diff --git a/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/type-param/snapshots/6-AST-Alignment-Tokens.shot b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/type-param/snapshots/6-AST-Alignment-Tokens.shot
new file mode 100644
index 000000000000..581d856705d2
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/type-param/snapshots/6-AST-Alignment-Tokens.shot
@@ -0,0 +1,6 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ClassDeclaration type-param AST Alignment - Token 1`] = `
+"Snapshot Diff:
+Compared values have no visual difference."
+`;
diff --git a/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/type-parameters-extends-type-parameters/fixture.ts b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/type-parameters-extends-type-param/fixture.ts
similarity index 100%
rename from packages/ast-spec/src/declaration/ClassDeclaration/fixtures/type-parameters-extends-type-parameters/fixture.ts
rename to packages/ast-spec/src/declaration/ClassDeclaration/fixtures/type-parameters-extends-type-param/fixture.ts
diff --git a/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/type-parameters-extends-type-parameters/snapshots/1-TSESTree-AST.shot b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/type-parameters-extends-type-param/snapshots/1-TSESTree-AST.shot
similarity index 96%
rename from packages/ast-spec/src/declaration/ClassDeclaration/fixtures/type-parameters-extends-type-parameters/snapshots/1-TSESTree-AST.shot
rename to packages/ast-spec/src/declaration/ClassDeclaration/fixtures/type-parameters-extends-type-param/snapshots/1-TSESTree-AST.shot
index 7fa282280172..aac248040d84 100644
--- a/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/type-parameters-extends-type-parameters/snapshots/1-TSESTree-AST.shot
+++ b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/type-parameters-extends-type-param/snapshots/1-TSESTree-AST.shot
@@ -1,6 +1,6 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
-exports[`AST Fixtures declaration ClassDeclaration type-parameters-extends-type-parameters TSESTree - AST 1`] = `
+exports[`AST Fixtures declaration ClassDeclaration type-parameters-extends-type-param TSESTree - AST 1`] = `
 Program {
   type: "Program",
   body: Array [
@@ -71,6 +71,7 @@ Program {
         params: Array [
           TSTypeParameter {
             type: "TSTypeParameter",
+            in: false,
             name: Identifier {
               type: "Identifier",
               name: "T",
@@ -81,6 +82,7 @@ Program {
                 end: { column: 11, line: 1 },
               },
             },
+            out: false,
 
             range: [10, 11],
             loc: {
diff --git a/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/type-parameters-extends-type-parameters/snapshots/2-TSESTree-Tokens.shot b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/type-parameters-extends-type-param/snapshots/2-TSESTree-Tokens.shot
similarity index 97%
rename from packages/ast-spec/src/declaration/ClassDeclaration/fixtures/type-parameters-extends-type-parameters/snapshots/2-TSESTree-Tokens.shot
rename to packages/ast-spec/src/declaration/ClassDeclaration/fixtures/type-parameters-extends-type-param/snapshots/2-TSESTree-Tokens.shot
index f73a167dba3e..f697768aad0d 100644
--- a/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/type-parameters-extends-type-parameters/snapshots/2-TSESTree-Tokens.shot
+++ b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/type-parameters-extends-type-param/snapshots/2-TSESTree-Tokens.shot
@@ -1,6 +1,6 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
-exports[`AST Fixtures declaration ClassDeclaration type-parameters-extends-type-parameters TSESTree - Tokens 1`] = `
+exports[`AST Fixtures declaration ClassDeclaration type-parameters-extends-type-param TSESTree - Tokens 1`] = `
 Array [
   Keyword {
     type: "Keyword",
diff --git a/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/type-parameters-extends-type-parameters/snapshots/3-Babel-AST.shot b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/type-parameters-extends-type-param/snapshots/3-Babel-AST.shot
similarity index 98%
rename from packages/ast-spec/src/declaration/ClassDeclaration/fixtures/type-parameters-extends-type-parameters/snapshots/3-Babel-AST.shot
rename to packages/ast-spec/src/declaration/ClassDeclaration/fixtures/type-parameters-extends-type-param/snapshots/3-Babel-AST.shot
index 7c5a5149bbed..e5856d26fbc8 100644
--- a/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/type-parameters-extends-type-parameters/snapshots/3-Babel-AST.shot
+++ b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/type-parameters-extends-type-param/snapshots/3-Babel-AST.shot
@@ -1,6 +1,6 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
-exports[`AST Fixtures declaration ClassDeclaration type-parameters-extends-type-parameters Babel - AST 1`] = `
+exports[`AST Fixtures declaration ClassDeclaration type-parameters-extends-type-param Babel - AST 1`] = `
 Program {
   type: "Program",
   body: Array [
diff --git a/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/type-parameters-extends-type-parameters/snapshots/4-Babel-Tokens.shot b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/type-parameters-extends-type-param/snapshots/4-Babel-Tokens.shot
similarity index 97%
rename from packages/ast-spec/src/declaration/ClassDeclaration/fixtures/type-parameters-extends-type-parameters/snapshots/4-Babel-Tokens.shot
rename to packages/ast-spec/src/declaration/ClassDeclaration/fixtures/type-parameters-extends-type-param/snapshots/4-Babel-Tokens.shot
index 17ca652dc4a9..97d16c68e189 100644
--- a/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/type-parameters-extends-type-parameters/snapshots/4-Babel-Tokens.shot
+++ b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/type-parameters-extends-type-param/snapshots/4-Babel-Tokens.shot
@@ -1,6 +1,6 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
-exports[`AST Fixtures declaration ClassDeclaration type-parameters-extends-type-parameters Babel - Tokens 1`] = `
+exports[`AST Fixtures declaration ClassDeclaration type-parameters-extends-type-param Babel - Tokens 1`] = `
 Array [
   Keyword {
     type: "Keyword",
diff --git a/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/type-parameters-extends-type-parameters/snapshots/5-AST-Alignment-AST.shot b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/type-parameters-extends-type-param/snapshots/5-AST-Alignment-AST.shot
similarity index 96%
rename from packages/ast-spec/src/declaration/ClassDeclaration/fixtures/type-parameters-extends-type-parameters/snapshots/5-AST-Alignment-AST.shot
rename to packages/ast-spec/src/declaration/ClassDeclaration/fixtures/type-parameters-extends-type-param/snapshots/5-AST-Alignment-AST.shot
index 70cae74b3003..f6d5a3c73b31 100644
--- a/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/type-parameters-extends-type-parameters/snapshots/5-AST-Alignment-AST.shot
+++ b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/type-parameters-extends-type-param/snapshots/5-AST-Alignment-AST.shot
@@ -1,6 +1,6 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
-exports[`AST Fixtures declaration ClassDeclaration type-parameters-extends-type-parameters AST Alignment - AST 1`] = `
+exports[`AST Fixtures declaration ClassDeclaration type-parameters-extends-type-param AST Alignment - AST 1`] = `
 "Snapshot Diff:
 - TSESTree
 + Babel
@@ -75,6 +75,7 @@ exports[`AST Fixtures declaration ClassDeclaration type-parameters-extends-type-
           params: Array [
             TSTypeParameter {
               type: 'TSTypeParameter',
+-             in: false,
 -             name: Identifier {
 -               type: 'Identifier',
 -               name: 'T',
@@ -85,6 +86,7 @@ exports[`AST Fixtures declaration ClassDeclaration type-parameters-extends-type-
 -                 end: { column: 11, line: 1 },
 -               },
 -             },
+-             out: false,
 +             name: 'T',
 
               range: [10, 11],
diff --git a/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/type-parameters/snapshots/6-AST-Alignment-Tokens.shot b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/type-parameters-extends-type-param/snapshots/6-AST-Alignment-Tokens.shot
similarity index 76%
rename from packages/ast-spec/src/declaration/ClassDeclaration/fixtures/type-parameters/snapshots/6-AST-Alignment-Tokens.shot
rename to packages/ast-spec/src/declaration/ClassDeclaration/fixtures/type-parameters-extends-type-param/snapshots/6-AST-Alignment-Tokens.shot
index a99d685df3d6..01862c4c7514 100644
--- a/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/type-parameters/snapshots/6-AST-Alignment-Tokens.shot
+++ b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/type-parameters-extends-type-param/snapshots/6-AST-Alignment-Tokens.shot
@@ -1,6 +1,6 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
-exports[`AST Fixtures declaration ClassDeclaration type-parameters AST Alignment - Token 1`] = `
+exports[`AST Fixtures declaration ClassDeclaration type-parameters-extends-type-param AST Alignment - Token 1`] = `
 "Snapshot Diff:
 Compared values have no visual difference."
 `;
diff --git a/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/type-parameters-extends-type-parameters/snapshots/6-AST-Alignment-Tokens.shot b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/type-parameters-extends-type-parameters/snapshots/6-AST-Alignment-Tokens.shot
deleted file mode 100644
index 4e5329e739f9..000000000000
--- a/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/type-parameters-extends-type-parameters/snapshots/6-AST-Alignment-Tokens.shot
+++ /dev/null
@@ -1,6 +0,0 @@
-// Jest Snapshot v1, https://goo.gl/fbAQLP
-
-exports[`AST Fixtures declaration ClassDeclaration type-parameters-extends-type-parameters AST Alignment - Token 1`] = `
-"Snapshot Diff:
-Compared values have no visual difference."
-`;
diff --git a/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/with-member-one/fixture.ts b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/with-member-one/fixture.ts
new file mode 100644
index 000000000000..b790f0b57f60
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/with-member-one/fixture.ts
@@ -0,0 +1,3 @@
+class Foo {
+  prop;
+}
diff --git a/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/with-member-one/snapshots/1-TSESTree-AST.shot b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/with-member-one/snapshots/1-TSESTree-AST.shot
new file mode 100644
index 000000000000..bdbfa5822bb2
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/with-member-one/snapshots/1-TSESTree-AST.shot
@@ -0,0 +1,71 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ClassDeclaration with-member-one TSESTree - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    ClassDeclaration {
+      type: "ClassDeclaration",
+      body: ClassBody {
+        type: "ClassBody",
+        body: Array [
+          PropertyDefinition {
+            type: "PropertyDefinition",
+            computed: false,
+            declare: false,
+            key: Identifier {
+              type: "Identifier",
+              name: "prop",
+
+              range: [14, 18],
+              loc: {
+                start: { column: 2, line: 2 },
+                end: { column: 6, line: 2 },
+              },
+            },
+            override: false,
+            static: false,
+            value: null,
+
+            range: [14, 19],
+            loc: {
+              start: { column: 2, line: 2 },
+              end: { column: 7, line: 2 },
+            },
+          },
+        ],
+
+        range: [10, 21],
+        loc: {
+          start: { column: 10, line: 1 },
+          end: { column: 1, line: 3 },
+        },
+      },
+      id: Identifier {
+        type: "Identifier",
+        name: "Foo",
+
+        range: [6, 9],
+        loc: {
+          start: { column: 6, line: 1 },
+          end: { column: 9, line: 1 },
+        },
+      },
+      superClass: null,
+
+      range: [0, 21],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 1, line: 3 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 22],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 4 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/with-member-one/snapshots/2-TSESTree-Tokens.shot b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/with-member-one/snapshots/2-TSESTree-Tokens.shot
new file mode 100644
index 000000000000..1184bd1ae083
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/with-member-one/snapshots/2-TSESTree-Tokens.shot
@@ -0,0 +1,66 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ClassDeclaration with-member-one TSESTree - Tokens 1`] = `
+Array [
+  Keyword {
+    type: "Keyword",
+    value: "class",
+
+    range: [0, 5],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 5, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "Foo",
+
+    range: [6, 9],
+    loc: {
+      start: { column: 6, line: 1 },
+      end: { column: 9, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "{",
+
+    range: [10, 11],
+    loc: {
+      start: { column: 10, line: 1 },
+      end: { column: 11, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "prop",
+
+    range: [14, 18],
+    loc: {
+      start: { column: 2, line: 2 },
+      end: { column: 6, line: 2 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ";",
+
+    range: [18, 19],
+    loc: {
+      start: { column: 6, line: 2 },
+      end: { column: 7, line: 2 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "}",
+
+    range: [20, 21],
+    loc: {
+      start: { column: 0, line: 3 },
+      end: { column: 1, line: 3 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/with-member-one/snapshots/3-Babel-AST.shot b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/with-member-one/snapshots/3-Babel-AST.shot
new file mode 100644
index 000000000000..df5b728f5588
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/with-member-one/snapshots/3-Babel-AST.shot
@@ -0,0 +1,69 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ClassDeclaration with-member-one Babel - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    ClassDeclaration {
+      type: "ClassDeclaration",
+      body: ClassBody {
+        type: "ClassBody",
+        body: Array [
+          PropertyDefinition {
+            type: "PropertyDefinition",
+            computed: false,
+            key: Identifier {
+              type: "Identifier",
+              name: "prop",
+
+              range: [14, 18],
+              loc: {
+                start: { column: 2, line: 2 },
+                end: { column: 6, line: 2 },
+              },
+            },
+            static: false,
+            value: null,
+
+            range: [14, 19],
+            loc: {
+              start: { column: 2, line: 2 },
+              end: { column: 7, line: 2 },
+            },
+          },
+        ],
+
+        range: [10, 21],
+        loc: {
+          start: { column: 10, line: 1 },
+          end: { column: 1, line: 3 },
+        },
+      },
+      id: Identifier {
+        type: "Identifier",
+        name: "Foo",
+
+        range: [6, 9],
+        loc: {
+          start: { column: 6, line: 1 },
+          end: { column: 9, line: 1 },
+        },
+      },
+      superClass: null,
+
+      range: [0, 21],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 1, line: 3 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 22],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 4 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/with-member-one/snapshots/4-Babel-Tokens.shot b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/with-member-one/snapshots/4-Babel-Tokens.shot
new file mode 100644
index 000000000000..3fe5916a116c
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/with-member-one/snapshots/4-Babel-Tokens.shot
@@ -0,0 +1,66 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ClassDeclaration with-member-one Babel - Tokens 1`] = `
+Array [
+  Keyword {
+    type: "Keyword",
+    value: "class",
+
+    range: [0, 5],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 5, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "Foo",
+
+    range: [6, 9],
+    loc: {
+      start: { column: 6, line: 1 },
+      end: { column: 9, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "{",
+
+    range: [10, 11],
+    loc: {
+      start: { column: 10, line: 1 },
+      end: { column: 11, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "prop",
+
+    range: [14, 18],
+    loc: {
+      start: { column: 2, line: 2 },
+      end: { column: 6, line: 2 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ";",
+
+    range: [18, 19],
+    loc: {
+      start: { column: 6, line: 2 },
+      end: { column: 7, line: 2 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "}",
+
+    range: [20, 21],
+    loc: {
+      start: { column: 0, line: 3 },
+      end: { column: 1, line: 3 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/with-member-one/snapshots/5-AST-Alignment-AST.shot b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/with-member-one/snapshots/5-AST-Alignment-AST.shot
new file mode 100644
index 000000000000..121e647439e9
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/with-member-one/snapshots/5-AST-Alignment-AST.shot
@@ -0,0 +1,75 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ClassDeclaration with-member-one AST Alignment - AST 1`] = `
+"Snapshot Diff:
+- TSESTree
++ Babel
+
+  Program {
+    type: 'Program',
+    body: Array [
+      ClassDeclaration {
+        type: 'ClassDeclaration',
+        body: ClassBody {
+          type: 'ClassBody',
+          body: Array [
+            PropertyDefinition {
+              type: 'PropertyDefinition',
+              computed: false,
+-             declare: false,
+              key: Identifier {
+                type: 'Identifier',
+                name: 'prop',
+
+                range: [14, 18],
+                loc: {
+                  start: { column: 2, line: 2 },
+                  end: { column: 6, line: 2 },
+                },
+              },
+-             override: false,
+              static: false,
+              value: null,
+
+              range: [14, 19],
+              loc: {
+                start: { column: 2, line: 2 },
+                end: { column: 7, line: 2 },
+              },
+            },
+          ],
+
+          range: [10, 21],
+          loc: {
+            start: { column: 10, line: 1 },
+            end: { column: 1, line: 3 },
+          },
+        },
+        id: Identifier {
+          type: 'Identifier',
+          name: 'Foo',
+
+          range: [6, 9],
+          loc: {
+            start: { column: 6, line: 1 },
+            end: { column: 9, line: 1 },
+          },
+        },
+        superClass: null,
+
+        range: [0, 21],
+        loc: {
+          start: { column: 0, line: 1 },
+          end: { column: 1, line: 3 },
+        },
+      },
+    ],
+    sourceType: 'script',
+
+    range: [0, 22],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 0, line: 4 },
+    },
+  }"
+`;
diff --git a/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/with-member-one/snapshots/6-AST-Alignment-Tokens.shot b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/with-member-one/snapshots/6-AST-Alignment-Tokens.shot
new file mode 100644
index 000000000000..89d6bb8a18ea
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/with-member-one/snapshots/6-AST-Alignment-Tokens.shot
@@ -0,0 +1,6 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ClassDeclaration with-member-one AST Alignment - Token 1`] = `
+"Snapshot Diff:
+Compared values have no visual difference."
+`;
diff --git a/packages/ast-spec/src/declaration/ClassDeclaration/spec.ts b/packages/ast-spec/src/declaration/ClassDeclaration/spec.ts
index 2154b8863a02..50112b70b5e1 100644
--- a/packages/ast-spec/src/declaration/ClassDeclaration/spec.ts
+++ b/packages/ast-spec/src/declaration/ClassDeclaration/spec.ts
@@ -1,6 +1,19 @@
 import type { AST_NODE_TYPES } from '../../ast-node-types';
-import type { ClassDeclarationBase } from '../../base/ClassDeclarationBase';
+import type { ClassBase } from '../../base/ClassBase';
+import type { Identifier } from '../../expression/Identifier/spec';
 
-export interface ClassDeclaration extends ClassDeclarationBase {
+interface ClassDeclarationBase extends ClassBase {
   type: AST_NODE_TYPES.ClassDeclaration;
 }
+
+export interface ClassDeclarationWithName extends ClassDeclarationBase {
+  id: Identifier;
+}
+
+export interface ClassDeclarationWithOptionalName extends ClassDeclarationBase {
+  id: Identifier | null;
+}
+
+export type ClassDeclaration =
+  | ClassDeclarationWithName
+  | ClassDeclarationWithOptionalName;
diff --git a/packages/ast-spec/src/declaration/ExportAllDeclaration/fixtures/_error_/kind-type/fixture.ts b/packages/ast-spec/src/declaration/ExportAllDeclaration/fixtures/_error_/kind-type/fixture.ts
new file mode 100644
index 000000000000..0a8ce4f553c8
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ExportAllDeclaration/fixtures/_error_/kind-type/fixture.ts
@@ -0,0 +1 @@
+export type * as x from 'a';
diff --git a/packages/ast-spec/src/declaration/ExportAllDeclaration/fixtures/_error_/kind-type/snapshots/1-TSESTree-AST.shot b/packages/ast-spec/src/declaration/ExportAllDeclaration/fixtures/_error_/kind-type/snapshots/1-TSESTree-AST.shot
new file mode 100644
index 000000000000..4e1ab2405d45
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ExportAllDeclaration/fixtures/_error_/kind-type/snapshots/1-TSESTree-AST.shot
@@ -0,0 +1,48 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ExportAllDeclaration kind-type TSESTree - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    ExportAllDeclaration {
+      type: "ExportAllDeclaration",
+      assertions: Array [],
+      exported: Identifier {
+        type: "Identifier",
+        name: "x",
+
+        range: [17, 18],
+        loc: {
+          start: { column: 17, line: 1 },
+          end: { column: 18, line: 1 },
+        },
+      },
+      exportKind: "type",
+      source: Literal {
+        type: "Literal",
+        raw: "'a'",
+        value: "a",
+
+        range: [24, 27],
+        loc: {
+          start: { column: 24, line: 1 },
+          end: { column: 27, line: 1 },
+        },
+      },
+
+      range: [0, 28],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 28, line: 1 },
+      },
+    },
+  ],
+  sourceType: "module",
+
+  range: [0, 29],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/ExportAllDeclaration/fixtures/_error_/kind-type/snapshots/1-TSESTree-Error.shot b/packages/ast-spec/src/declaration/ExportAllDeclaration/fixtures/_error_/kind-type/snapshots/1-TSESTree-Error.shot
new file mode 100644
index 000000000000..a28f9c4f9032
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ExportAllDeclaration/fixtures/_error_/kind-type/snapshots/1-TSESTree-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ExportAllDeclaration _error_ kind-type TSESTree - Error 1`] = `"NO ERROR"`;
diff --git a/packages/ast-spec/src/declaration/ExportAllDeclaration/fixtures/_error_/kind-type/snapshots/2-Babel-Error.shot b/packages/ast-spec/src/declaration/ExportAllDeclaration/fixtures/_error_/kind-type/snapshots/2-Babel-Error.shot
new file mode 100644
index 000000000000..18b68176cbec
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ExportAllDeclaration/fixtures/_error_/kind-type/snapshots/2-Babel-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ExportAllDeclaration _error_ kind-type Babel - Error 1`] = `[SyntaxError: Unexpected token (1:12)]`;
diff --git a/packages/ast-spec/src/declaration/ExportAllDeclaration/fixtures/_error_/kind-type/snapshots/2-TSESTree-Tokens.shot b/packages/ast-spec/src/declaration/ExportAllDeclaration/fixtures/_error_/kind-type/snapshots/2-TSESTree-Tokens.shot
new file mode 100644
index 000000000000..f5bfa8f5615e
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ExportAllDeclaration/fixtures/_error_/kind-type/snapshots/2-TSESTree-Tokens.shot
@@ -0,0 +1,86 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ExportAllDeclaration kind-type TSESTree - Tokens 1`] = `
+Array [
+  Keyword {
+    type: "Keyword",
+    value: "export",
+
+    range: [0, 6],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 6, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "type",
+
+    range: [7, 11],
+    loc: {
+      start: { column: 7, line: 1 },
+      end: { column: 11, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "*",
+
+    range: [12, 13],
+    loc: {
+      start: { column: 12, line: 1 },
+      end: { column: 13, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "as",
+
+    range: [14, 16],
+    loc: {
+      start: { column: 14, line: 1 },
+      end: { column: 16, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "x",
+
+    range: [17, 18],
+    loc: {
+      start: { column: 17, line: 1 },
+      end: { column: 18, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "from",
+
+    range: [19, 23],
+    loc: {
+      start: { column: 19, line: 1 },
+      end: { column: 23, line: 1 },
+    },
+  },
+  String {
+    type: "String",
+    value: "'a'",
+
+    range: [24, 27],
+    loc: {
+      start: { column: 24, line: 1 },
+      end: { column: 27, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ";",
+
+    range: [27, 28],
+    loc: {
+      start: { column: 27, line: 1 },
+      end: { column: 28, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/ExportAllDeclaration/fixtures/_error_/kind-type/snapshots/3-Alignment-Error.shot b/packages/ast-spec/src/declaration/ExportAllDeclaration/fixtures/_error_/kind-type/snapshots/3-Alignment-Error.shot
new file mode 100644
index 000000000000..f9e05e0f6ea8
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ExportAllDeclaration/fixtures/_error_/kind-type/snapshots/3-Alignment-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ExportAllDeclaration _error_ kind-type Error Alignment 1`] = `"Babel errored but TSESTree didn't"`;
diff --git a/packages/ast-spec/src/declaration/ExportAllDeclaration/fixtures/_error_/no-source/fixture.ts b/packages/ast-spec/src/declaration/ExportAllDeclaration/fixtures/_error_/missing-source/fixture.ts
similarity index 100%
rename from packages/ast-spec/src/declaration/ExportAllDeclaration/fixtures/_error_/no-source/fixture.ts
rename to packages/ast-spec/src/declaration/ExportAllDeclaration/fixtures/_error_/missing-source/fixture.ts
diff --git a/packages/ast-spec/src/declaration/ExportAllDeclaration/fixtures/_error_/missing-source/snapshots/1-TSESTree-Error.shot b/packages/ast-spec/src/declaration/ExportAllDeclaration/fixtures/_error_/missing-source/snapshots/1-TSESTree-Error.shot
new file mode 100644
index 000000000000..d3c411c7ec3a
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ExportAllDeclaration/fixtures/_error_/missing-source/snapshots/1-TSESTree-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ExportAllDeclaration _error_ missing-source TSESTree - Error 1`] = `[TSError: Expression expected.]`;
diff --git a/packages/ast-spec/src/declaration/ExportAllDeclaration/fixtures/_error_/missing-source/snapshots/2-Babel-Error.shot b/packages/ast-spec/src/declaration/ExportAllDeclaration/fixtures/_error_/missing-source/snapshots/2-Babel-Error.shot
new file mode 100644
index 000000000000..b45b0c8fc850
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ExportAllDeclaration/fixtures/_error_/missing-source/snapshots/2-Babel-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ExportAllDeclaration _error_ missing-source Babel - Error 1`] = `[SyntaxError: Unexpected token (1:13)]`;
diff --git a/packages/ast-spec/src/declaration/ExportAllDeclaration/fixtures/_error_/missing-source/snapshots/3-Alignment-Error.shot b/packages/ast-spec/src/declaration/ExportAllDeclaration/fixtures/_error_/missing-source/snapshots/3-Alignment-Error.shot
new file mode 100644
index 000000000000..89889f0ae319
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ExportAllDeclaration/fixtures/_error_/missing-source/snapshots/3-Alignment-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ExportAllDeclaration _error_ missing-source Error Alignment 1`] = `"Both errored"`;
diff --git a/packages/ast-spec/src/declaration/ExportAllDeclaration/fixtures/_error_/no-source/snapshots/1-TSESTree-Error.shot b/packages/ast-spec/src/declaration/ExportAllDeclaration/fixtures/_error_/no-source/snapshots/1-TSESTree-Error.shot
deleted file mode 100644
index acdaf4c735f9..000000000000
--- a/packages/ast-spec/src/declaration/ExportAllDeclaration/fixtures/_error_/no-source/snapshots/1-TSESTree-Error.shot
+++ /dev/null
@@ -1,3 +0,0 @@
-// Jest Snapshot v1, https://goo.gl/fbAQLP
-
-exports[`AST Fixtures declaration ExportAllDeclaration _error_ no-source TSESTree - Error 1`] = `[TSError: Expression expected.]`;
diff --git a/packages/ast-spec/src/declaration/ExportAllDeclaration/fixtures/_error_/no-source/snapshots/2-Babel-Error.shot b/packages/ast-spec/src/declaration/ExportAllDeclaration/fixtures/_error_/no-source/snapshots/2-Babel-Error.shot
deleted file mode 100644
index 8bd09ace8dc6..000000000000
--- a/packages/ast-spec/src/declaration/ExportAllDeclaration/fixtures/_error_/no-source/snapshots/2-Babel-Error.shot
+++ /dev/null
@@ -1,3 +0,0 @@
-// Jest Snapshot v1, https://goo.gl/fbAQLP
-
-exports[`AST Fixtures declaration ExportAllDeclaration _error_ no-source Babel - Error 1`] = `[SyntaxError: Unexpected token (1:13)]`;
diff --git a/packages/ast-spec/src/declaration/ExportAllDeclaration/fixtures/_error_/no-source/snapshots/3-Alignment-Error.shot b/packages/ast-spec/src/declaration/ExportAllDeclaration/fixtures/_error_/no-source/snapshots/3-Alignment-Error.shot
deleted file mode 100644
index c2ac962baac0..000000000000
--- a/packages/ast-spec/src/declaration/ExportAllDeclaration/fixtures/_error_/no-source/snapshots/3-Alignment-Error.shot
+++ /dev/null
@@ -1,3 +0,0 @@
-// Jest Snapshot v1, https://goo.gl/fbAQLP
-
-exports[`AST Fixtures declaration ExportAllDeclaration _error_ no-source Error Alignment 1`] = `"Both errored"`;
diff --git a/packages/ast-spec/src/declaration/ExportAllDeclaration/spec.ts b/packages/ast-spec/src/declaration/ExportAllDeclaration/spec.ts
index 5cf3301a50db..168f7b40b611 100644
--- a/packages/ast-spec/src/declaration/ExportAllDeclaration/spec.ts
+++ b/packages/ast-spec/src/declaration/ExportAllDeclaration/spec.ts
@@ -7,8 +7,24 @@ import type { ExportKind } from '../ExportAndImportKind';
 
 export interface ExportAllDeclaration extends BaseNode {
   type: AST_NODE_TYPES.ExportAllDeclaration;
-  source: StringLiteral | null;
-  exportKind: ExportKind;
-  exported: Identifier | null;
+  /**
+   * The assertions declared for the export.
+   * ```
+   * export * from 'mod' assert { type: 'json' };
+   * ```
+   */
   assertions: ImportAttribute[];
+  /**
+   * The name for the exported items. `null` if no name is assigned.
+   */
+  exported: Identifier | null;
+  /**
+   * The kind of the export.
+   */
+  // TODO(#1852) - breaking change remove this because it is a semantic error to have it
+  exportKind: ExportKind;
+  /**
+   * The source module being exported from.
+   */
+  source: StringLiteral;
 }
diff --git a/packages/ast-spec/src/declaration/ExportDefaultDeclaration/spec.ts b/packages/ast-spec/src/declaration/ExportDefaultDeclaration/spec.ts
index 2cfe1cce5b33..51b1248854a8 100644
--- a/packages/ast-spec/src/declaration/ExportDefaultDeclaration/spec.ts
+++ b/packages/ast-spec/src/declaration/ExportDefaultDeclaration/spec.ts
@@ -1,15 +1,16 @@
 import type { AST_NODE_TYPES } from '../../ast-node-types';
 import type { BaseNode } from '../../base/BaseNode';
-import type { ExportDeclaration } from '../../unions/ExportDeclaration';
-import type { Expression } from '../../unions/Expression';
+import type { DefaultExportDeclarations } from '../../unions/ExportDeclaration';
 import type { ExportKind } from '../ExportAndImportKind';
 
 export interface ExportDefaultDeclaration extends BaseNode {
   type: AST_NODE_TYPES.ExportDefaultDeclaration;
-  declaration:
-    | // TODO(error handling) - the following are disallowed syntactically, but allowed by TS error recovery:
-    // TSEnumDeclaration, TSModuleDeclaration, TSTypeAliasDeclaration, VariableDeclaration
-    ExportDeclaration
-    | Expression;
+  /**
+   * The declaration being exported.
+   */
+  declaration: DefaultExportDeclarations;
+  /**
+   * The kind of the export.
+   */
   exportKind: ExportKind;
 }
diff --git a/packages/ast-spec/src/declaration/ExportNamedDeclaration/spec.ts b/packages/ast-spec/src/declaration/ExportNamedDeclaration/spec.ts
index 3e2989b74990..061c53f4b469 100644
--- a/packages/ast-spec/src/declaration/ExportNamedDeclaration/spec.ts
+++ b/packages/ast-spec/src/declaration/ExportNamedDeclaration/spec.ts
@@ -3,15 +3,73 @@ import type { BaseNode } from '../../base/BaseNode';
 import type { StringLiteral } from '../../expression/literal/StringLiteral/spec';
 import type { ExportSpecifier } from '../../special/ExportSpecifier/spec';
 import type { ImportAttribute } from '../../special/ImportAttribute/spec';
-import type { ExportDeclaration } from '../../unions/ExportDeclaration';
+import type { NamedExportDeclarations } from '../../unions/ExportDeclaration';
 import type { ExportKind } from '../ExportAndImportKind';
 
-export interface ExportNamedDeclaration extends BaseNode {
+interface ExportNamedDeclarationBase extends BaseNode {
   type: AST_NODE_TYPES.ExportNamedDeclaration;
-  // TODO(error handling) - ClassExpression is not valid here
-  declaration: ExportDeclaration | null;
-  specifiers: ExportSpecifier[];
-  source: StringLiteral | null;
+  /**
+   * The assertions declared for the export.
+   * ```
+   * export { foo } from 'mod' assert { type: 'json' };
+   * ```
+   * This will be an empty array if `source` is `null`
+   */
+  assertions: ImportAttribute[];
+  /**
+   * The exported declaration.
+   * ```
+   * export const x = 1;
+   * ```
+   * This will be `null` if `source` is not `null`, or if there are `specifiers`
+   */
+  declaration: NamedExportDeclarations | null;
+  /**
+   * The kind of the export.
+   */
   exportKind: ExportKind;
+  /**
+   * The source module being exported from.
+   */
+  source: StringLiteral | null;
+  /**
+   * The specifiers being exported.
+   * ```
+   * export { a, b };
+   * ```
+   * This will be an empty array if `declaration` is not `null`
+   */
+  specifiers: ExportSpecifier[];
+}
+
+export interface ExportNamedDeclarationWithoutSourceWithMultiple
+  extends ExportNamedDeclarationBase {
+  // this will always be empty array
   assertions: ImportAttribute[];
+  declaration: NamedExportDeclarations;
+  source: null;
+  specifiers: ExportSpecifier[];
 }
+
+export interface ExportNamedDeclarationWithoutSourceWithSingle
+  extends ExportNamedDeclarationBase {
+  // this will always be empty array
+  assertions: ImportAttribute[];
+  declaration: null;
+  source: null;
+  // this will always be empty array
+  specifiers: ExportSpecifier[];
+}
+
+export interface ExportNamedDeclarationWithSource
+  extends ExportNamedDeclarationBase {
+  assertions: ImportAttribute[];
+  declaration: null;
+  source: StringLiteral;
+  specifiers: ExportSpecifier[];
+}
+
+export type ExportNamedDeclaration =
+  | ExportNamedDeclarationWithoutSourceWithMultiple
+  | ExportNamedDeclarationWithoutSourceWithSingle
+  | ExportNamedDeclarationWithSource;
diff --git a/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/_error_/missing-id-and-not-exported/fixture.ts b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/_error_/missing-id-and-not-exported/fixture.ts
new file mode 100644
index 000000000000..6c532730c0b4
--- /dev/null
+++ b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/_error_/missing-id-and-not-exported/fixture.ts
@@ -0,0 +1 @@
+function () {}
diff --git a/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/_error_/missing-id-and-not-exported/snapshots/1-TSESTree-Error.shot b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/_error_/missing-id-and-not-exported/snapshots/1-TSESTree-Error.shot
new file mode 100644
index 000000000000..e8630b3f99ce
--- /dev/null
+++ b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/_error_/missing-id-and-not-exported/snapshots/1-TSESTree-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration FunctionDeclaration _error_ missing-id-and-not-exported TSESTree - Error 1`] = `[TSError: Identifier expected.]`;
diff --git a/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/_error_/missing-id-and-not-exported/snapshots/2-Babel-Error.shot b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/_error_/missing-id-and-not-exported/snapshots/2-Babel-Error.shot
new file mode 100644
index 000000000000..d0110ccac63f
--- /dev/null
+++ b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/_error_/missing-id-and-not-exported/snapshots/2-Babel-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration FunctionDeclaration _error_ missing-id-and-not-exported Babel - Error 1`] = `[SyntaxError: Unexpected token (1:9)]`;
diff --git a/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/_error_/missing-id-and-not-exported/snapshots/3-Alignment-Error.shot b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/_error_/missing-id-and-not-exported/snapshots/3-Alignment-Error.shot
new file mode 100644
index 000000000000..adae3f26337b
--- /dev/null
+++ b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/_error_/missing-id-and-not-exported/snapshots/3-Alignment-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration FunctionDeclaration _error_ missing-id-and-not-exported Error Alignment 1`] = `"Both errored"`;
diff --git a/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/_error_/missing-type-param/fixture.ts b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/_error_/missing-type-param/fixture.ts
new file mode 100644
index 000000000000..0988137a7e71
--- /dev/null
+++ b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/_error_/missing-type-param/fixture.ts
@@ -0,0 +1 @@
+function foo<>() {}
diff --git a/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/_error_/missing-type-param/snapshots/1-TSESTree-Error.shot b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/_error_/missing-type-param/snapshots/1-TSESTree-Error.shot
new file mode 100644
index 000000000000..2ffb9878bc95
--- /dev/null
+++ b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/_error_/missing-type-param/snapshots/1-TSESTree-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration FunctionDeclaration _error_ missing-type-param TSESTree - Error 1`] = `"NO ERROR"`;
diff --git a/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/_error_/missing-type-param/snapshots/2-Babel-Error.shot b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/_error_/missing-type-param/snapshots/2-Babel-Error.shot
new file mode 100644
index 000000000000..83a2a868f15a
--- /dev/null
+++ b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/_error_/missing-type-param/snapshots/2-Babel-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration FunctionDeclaration _error_ missing-type-param Babel - Error 1`] = `[SyntaxError: Type parameter list cannot be empty. (1:12)]`;
diff --git a/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/_error_/missing-type-param/snapshots/3-Alignment-Error.shot b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/_error_/missing-type-param/snapshots/3-Alignment-Error.shot
new file mode 100644
index 000000000000..04a70d3af29f
--- /dev/null
+++ b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/_error_/missing-type-param/snapshots/3-Alignment-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration FunctionDeclaration _error_ missing-type-param Error Alignment 1`] = `"Babel errored but TSESTree didn't"`;
diff --git a/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/_error_/non-identifier-name/fixture.ts b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/_error_/non-identifier-name/fixture.ts
new file mode 100644
index 000000000000..4e06a77dc7f5
--- /dev/null
+++ b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/_error_/non-identifier-name/fixture.ts
@@ -0,0 +1 @@
+function 1() {}
diff --git a/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/_error_/non-identifier-name/snapshots/1-TSESTree-Error.shot b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/_error_/non-identifier-name/snapshots/1-TSESTree-Error.shot
new file mode 100644
index 000000000000..156bebb725cf
--- /dev/null
+++ b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/_error_/non-identifier-name/snapshots/1-TSESTree-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration FunctionDeclaration _error_ non-identifier-name TSESTree - Error 1`] = `[TSError: Identifier expected.]`;
diff --git a/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/_error_/non-identifier-name/snapshots/2-Babel-Error.shot b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/_error_/non-identifier-name/snapshots/2-Babel-Error.shot
new file mode 100644
index 000000000000..d23f3eff9555
--- /dev/null
+++ b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/_error_/non-identifier-name/snapshots/2-Babel-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration FunctionDeclaration _error_ non-identifier-name Babel - Error 1`] = `[SyntaxError: Unexpected token (1:9)]`;
diff --git a/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/_error_/non-identifier-name/snapshots/3-Alignment-Error.shot b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/_error_/non-identifier-name/snapshots/3-Alignment-Error.shot
new file mode 100644
index 000000000000..f34f77cd1b85
--- /dev/null
+++ b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/_error_/non-identifier-name/snapshots/3-Alignment-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration FunctionDeclaration _error_ non-identifier-name Error Alignment 1`] = `"Both errored"`;
diff --git a/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/_error_/non-identifier-type-param/fixture.ts b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/_error_/non-identifier-type-param/fixture.ts
new file mode 100644
index 000000000000..99644e47f365
--- /dev/null
+++ b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/_error_/non-identifier-type-param/fixture.ts
@@ -0,0 +1 @@
+function foo<1>() {}
diff --git a/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/_error_/non-identifier-type-param/snapshots/1-TSESTree-Error.shot b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/_error_/non-identifier-type-param/snapshots/1-TSESTree-Error.shot
new file mode 100644
index 000000000000..8c643863afba
--- /dev/null
+++ b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/_error_/non-identifier-type-param/snapshots/1-TSESTree-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration FunctionDeclaration _error_ non-identifier-type-param TSESTree - Error 1`] = `[TSError: Type parameter declaration expected.]`;
diff --git a/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/_error_/non-identifier-type-param/snapshots/2-Babel-Error.shot b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/_error_/non-identifier-type-param/snapshots/2-Babel-Error.shot
new file mode 100644
index 000000000000..8be1b8d27a37
--- /dev/null
+++ b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/_error_/non-identifier-type-param/snapshots/2-Babel-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration FunctionDeclaration _error_ non-identifier-type-param Babel - Error 1`] = `[SyntaxError: Unexpected token (1:13)]`;
diff --git a/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/_error_/non-identifier-type-param/snapshots/3-Alignment-Error.shot b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/_error_/non-identifier-type-param/snapshots/3-Alignment-Error.shot
new file mode 100644
index 000000000000..f2b863d8647a
--- /dev/null
+++ b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/_error_/non-identifier-type-param/snapshots/3-Alignment-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration FunctionDeclaration _error_ non-identifier-type-param Error Alignment 1`] = `"Both errored"`;
diff --git a/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/async/fixture.ts b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/async/fixture.ts
new file mode 100644
index 000000000000..f9df9686dd67
--- /dev/null
+++ b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/async/fixture.ts
@@ -0,0 +1 @@
+async function foo() {}
diff --git a/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/async/snapshots/1-TSESTree-AST.shot b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/async/snapshots/1-TSESTree-AST.shot
new file mode 100644
index 000000000000..7a7cd7ea28a3
--- /dev/null
+++ b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/async/snapshots/1-TSESTree-AST.shot
@@ -0,0 +1,49 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration FunctionDeclaration async TSESTree - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    FunctionDeclaration {
+      type: "FunctionDeclaration",
+      async: true,
+      body: BlockStatement {
+        type: "BlockStatement",
+        body: Array [],
+
+        range: [21, 23],
+        loc: {
+          start: { column: 21, line: 1 },
+          end: { column: 23, line: 1 },
+        },
+      },
+      expression: false,
+      generator: false,
+      id: Identifier {
+        type: "Identifier",
+        name: "foo",
+
+        range: [15, 18],
+        loc: {
+          start: { column: 15, line: 1 },
+          end: { column: 18, line: 1 },
+        },
+      },
+      params: Array [],
+
+      range: [0, 23],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 23, line: 1 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 24],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/async/snapshots/2-TSESTree-Tokens.shot b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/async/snapshots/2-TSESTree-Tokens.shot
new file mode 100644
index 000000000000..3ca43d1e9fa1
--- /dev/null
+++ b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/async/snapshots/2-TSESTree-Tokens.shot
@@ -0,0 +1,76 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration FunctionDeclaration async TSESTree - Tokens 1`] = `
+Array [
+  Identifier {
+    type: "Identifier",
+    value: "async",
+
+    range: [0, 5],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 5, line: 1 },
+    },
+  },
+  Keyword {
+    type: "Keyword",
+    value: "function",
+
+    range: [6, 14],
+    loc: {
+      start: { column: 6, line: 1 },
+      end: { column: 14, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "foo",
+
+    range: [15, 18],
+    loc: {
+      start: { column: 15, line: 1 },
+      end: { column: 18, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "(",
+
+    range: [18, 19],
+    loc: {
+      start: { column: 18, line: 1 },
+      end: { column: 19, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ")",
+
+    range: [19, 20],
+    loc: {
+      start: { column: 19, line: 1 },
+      end: { column: 20, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "{",
+
+    range: [21, 22],
+    loc: {
+      start: { column: 21, line: 1 },
+      end: { column: 22, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "}",
+
+    range: [22, 23],
+    loc: {
+      start: { column: 22, line: 1 },
+      end: { column: 23, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/async/snapshots/3-Babel-AST.shot b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/async/snapshots/3-Babel-AST.shot
new file mode 100644
index 000000000000..c24f3da9207c
--- /dev/null
+++ b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/async/snapshots/3-Babel-AST.shot
@@ -0,0 +1,49 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration FunctionDeclaration async Babel - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    FunctionDeclaration {
+      type: "FunctionDeclaration",
+      async: true,
+      body: BlockStatement {
+        type: "BlockStatement",
+        body: Array [],
+
+        range: [21, 23],
+        loc: {
+          start: { column: 21, line: 1 },
+          end: { column: 23, line: 1 },
+        },
+      },
+      expression: false,
+      generator: false,
+      id: Identifier {
+        type: "Identifier",
+        name: "foo",
+
+        range: [15, 18],
+        loc: {
+          start: { column: 15, line: 1 },
+          end: { column: 18, line: 1 },
+        },
+      },
+      params: Array [],
+
+      range: [0, 23],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 23, line: 1 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 24],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/async/snapshots/4-Babel-Tokens.shot b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/async/snapshots/4-Babel-Tokens.shot
new file mode 100644
index 000000000000..22c009c000f1
--- /dev/null
+++ b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/async/snapshots/4-Babel-Tokens.shot
@@ -0,0 +1,76 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration FunctionDeclaration async Babel - Tokens 1`] = `
+Array [
+  Identifier {
+    type: "Identifier",
+    value: "async",
+
+    range: [0, 5],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 5, line: 1 },
+    },
+  },
+  Keyword {
+    type: "Keyword",
+    value: "function",
+
+    range: [6, 14],
+    loc: {
+      start: { column: 6, line: 1 },
+      end: { column: 14, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "foo",
+
+    range: [15, 18],
+    loc: {
+      start: { column: 15, line: 1 },
+      end: { column: 18, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "(",
+
+    range: [18, 19],
+    loc: {
+      start: { column: 18, line: 1 },
+      end: { column: 19, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ")",
+
+    range: [19, 20],
+    loc: {
+      start: { column: 19, line: 1 },
+      end: { column: 20, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "{",
+
+    range: [21, 22],
+    loc: {
+      start: { column: 21, line: 1 },
+      end: { column: 22, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "}",
+
+    range: [22, 23],
+    loc: {
+      start: { column: 22, line: 1 },
+      end: { column: 23, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/async/snapshots/5-AST-Alignment-AST.shot b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/async/snapshots/5-AST-Alignment-AST.shot
new file mode 100644
index 000000000000..fe3cf227fbae
--- /dev/null
+++ b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/async/snapshots/5-AST-Alignment-AST.shot
@@ -0,0 +1,6 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration FunctionDeclaration async AST Alignment - AST 1`] = `
+"Snapshot Diff:
+Compared values have no visual difference."
+`;
diff --git a/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/async/snapshots/6-AST-Alignment-Tokens.shot b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/async/snapshots/6-AST-Alignment-Tokens.shot
new file mode 100644
index 000000000000..b7e2ed7bd9aa
--- /dev/null
+++ b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/async/snapshots/6-AST-Alignment-Tokens.shot
@@ -0,0 +1,6 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration FunctionDeclaration async AST Alignment - Token 1`] = `
+"Snapshot Diff:
+Compared values have no visual difference."
+`;
diff --git a/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/empty/fixture.ts b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/empty/fixture.ts
new file mode 100644
index 000000000000..b0400ee9b26e
--- /dev/null
+++ b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/empty/fixture.ts
@@ -0,0 +1 @@
+function foo() {}
diff --git a/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/empty/snapshots/1-TSESTree-AST.shot b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/empty/snapshots/1-TSESTree-AST.shot
new file mode 100644
index 000000000000..e21b80de90ed
--- /dev/null
+++ b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/empty/snapshots/1-TSESTree-AST.shot
@@ -0,0 +1,49 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration FunctionDeclaration empty TSESTree - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    FunctionDeclaration {
+      type: "FunctionDeclaration",
+      async: false,
+      body: BlockStatement {
+        type: "BlockStatement",
+        body: Array [],
+
+        range: [15, 17],
+        loc: {
+          start: { column: 15, line: 1 },
+          end: { column: 17, line: 1 },
+        },
+      },
+      expression: false,
+      generator: false,
+      id: Identifier {
+        type: "Identifier",
+        name: "foo",
+
+        range: [9, 12],
+        loc: {
+          start: { column: 9, line: 1 },
+          end: { column: 12, line: 1 },
+        },
+      },
+      params: Array [],
+
+      range: [0, 17],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 17, line: 1 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 18],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/empty/snapshots/2-TSESTree-Tokens.shot b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/empty/snapshots/2-TSESTree-Tokens.shot
new file mode 100644
index 000000000000..d53355506df5
--- /dev/null
+++ b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/empty/snapshots/2-TSESTree-Tokens.shot
@@ -0,0 +1,66 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration FunctionDeclaration empty TSESTree - Tokens 1`] = `
+Array [
+  Keyword {
+    type: "Keyword",
+    value: "function",
+
+    range: [0, 8],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 8, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "foo",
+
+    range: [9, 12],
+    loc: {
+      start: { column: 9, line: 1 },
+      end: { column: 12, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "(",
+
+    range: [12, 13],
+    loc: {
+      start: { column: 12, line: 1 },
+      end: { column: 13, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ")",
+
+    range: [13, 14],
+    loc: {
+      start: { column: 13, line: 1 },
+      end: { column: 14, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "{",
+
+    range: [15, 16],
+    loc: {
+      start: { column: 15, line: 1 },
+      end: { column: 16, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "}",
+
+    range: [16, 17],
+    loc: {
+      start: { column: 16, line: 1 },
+      end: { column: 17, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/empty/snapshots/3-Babel-AST.shot b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/empty/snapshots/3-Babel-AST.shot
new file mode 100644
index 000000000000..e339b4afda47
--- /dev/null
+++ b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/empty/snapshots/3-Babel-AST.shot
@@ -0,0 +1,49 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration FunctionDeclaration empty Babel - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    FunctionDeclaration {
+      type: "FunctionDeclaration",
+      async: false,
+      body: BlockStatement {
+        type: "BlockStatement",
+        body: Array [],
+
+        range: [15, 17],
+        loc: {
+          start: { column: 15, line: 1 },
+          end: { column: 17, line: 1 },
+        },
+      },
+      expression: false,
+      generator: false,
+      id: Identifier {
+        type: "Identifier",
+        name: "foo",
+
+        range: [9, 12],
+        loc: {
+          start: { column: 9, line: 1 },
+          end: { column: 12, line: 1 },
+        },
+      },
+      params: Array [],
+
+      range: [0, 17],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 17, line: 1 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 18],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/empty/snapshots/4-Babel-Tokens.shot b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/empty/snapshots/4-Babel-Tokens.shot
new file mode 100644
index 000000000000..0b7e51f42351
--- /dev/null
+++ b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/empty/snapshots/4-Babel-Tokens.shot
@@ -0,0 +1,66 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration FunctionDeclaration empty Babel - Tokens 1`] = `
+Array [
+  Keyword {
+    type: "Keyword",
+    value: "function",
+
+    range: [0, 8],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 8, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "foo",
+
+    range: [9, 12],
+    loc: {
+      start: { column: 9, line: 1 },
+      end: { column: 12, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "(",
+
+    range: [12, 13],
+    loc: {
+      start: { column: 12, line: 1 },
+      end: { column: 13, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ")",
+
+    range: [13, 14],
+    loc: {
+      start: { column: 13, line: 1 },
+      end: { column: 14, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "{",
+
+    range: [15, 16],
+    loc: {
+      start: { column: 15, line: 1 },
+      end: { column: 16, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "}",
+
+    range: [16, 17],
+    loc: {
+      start: { column: 16, line: 1 },
+      end: { column: 17, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/empty/snapshots/5-AST-Alignment-AST.shot b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/empty/snapshots/5-AST-Alignment-AST.shot
new file mode 100644
index 000000000000..b08265806b56
--- /dev/null
+++ b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/empty/snapshots/5-AST-Alignment-AST.shot
@@ -0,0 +1,6 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration FunctionDeclaration empty AST Alignment - AST 1`] = `
+"Snapshot Diff:
+Compared values have no visual difference."
+`;
diff --git a/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/empty/snapshots/6-AST-Alignment-Tokens.shot b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/empty/snapshots/6-AST-Alignment-Tokens.shot
new file mode 100644
index 000000000000..de6b3f7e1164
--- /dev/null
+++ b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/empty/snapshots/6-AST-Alignment-Tokens.shot
@@ -0,0 +1,6 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration FunctionDeclaration empty AST Alignment - Token 1`] = `
+"Snapshot Diff:
+Compared values have no visual difference."
+`;
diff --git a/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/generator/fixture.ts b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/generator/fixture.ts
new file mode 100644
index 000000000000..f60d20a34b7e
--- /dev/null
+++ b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/generator/fixture.ts
@@ -0,0 +1 @@
+function* foo() {}
diff --git a/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/generator/snapshots/1-TSESTree-AST.shot b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/generator/snapshots/1-TSESTree-AST.shot
new file mode 100644
index 000000000000..7ad2d7a2dcef
--- /dev/null
+++ b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/generator/snapshots/1-TSESTree-AST.shot
@@ -0,0 +1,49 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration FunctionDeclaration generator TSESTree - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    FunctionDeclaration {
+      type: "FunctionDeclaration",
+      async: false,
+      body: BlockStatement {
+        type: "BlockStatement",
+        body: Array [],
+
+        range: [16, 18],
+        loc: {
+          start: { column: 16, line: 1 },
+          end: { column: 18, line: 1 },
+        },
+      },
+      expression: false,
+      generator: true,
+      id: Identifier {
+        type: "Identifier",
+        name: "foo",
+
+        range: [10, 13],
+        loc: {
+          start: { column: 10, line: 1 },
+          end: { column: 13, line: 1 },
+        },
+      },
+      params: Array [],
+
+      range: [0, 18],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 18, line: 1 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 19],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/generator/snapshots/2-TSESTree-Tokens.shot b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/generator/snapshots/2-TSESTree-Tokens.shot
new file mode 100644
index 000000000000..d6d229236840
--- /dev/null
+++ b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/generator/snapshots/2-TSESTree-Tokens.shot
@@ -0,0 +1,76 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration FunctionDeclaration generator TSESTree - Tokens 1`] = `
+Array [
+  Keyword {
+    type: "Keyword",
+    value: "function",
+
+    range: [0, 8],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 8, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "*",
+
+    range: [8, 9],
+    loc: {
+      start: { column: 8, line: 1 },
+      end: { column: 9, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "foo",
+
+    range: [10, 13],
+    loc: {
+      start: { column: 10, line: 1 },
+      end: { column: 13, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "(",
+
+    range: [13, 14],
+    loc: {
+      start: { column: 13, line: 1 },
+      end: { column: 14, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ")",
+
+    range: [14, 15],
+    loc: {
+      start: { column: 14, line: 1 },
+      end: { column: 15, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "{",
+
+    range: [16, 17],
+    loc: {
+      start: { column: 16, line: 1 },
+      end: { column: 17, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "}",
+
+    range: [17, 18],
+    loc: {
+      start: { column: 17, line: 1 },
+      end: { column: 18, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/generator/snapshots/3-Babel-AST.shot b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/generator/snapshots/3-Babel-AST.shot
new file mode 100644
index 000000000000..46d3edd3250d
--- /dev/null
+++ b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/generator/snapshots/3-Babel-AST.shot
@@ -0,0 +1,49 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration FunctionDeclaration generator Babel - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    FunctionDeclaration {
+      type: "FunctionDeclaration",
+      async: false,
+      body: BlockStatement {
+        type: "BlockStatement",
+        body: Array [],
+
+        range: [16, 18],
+        loc: {
+          start: { column: 16, line: 1 },
+          end: { column: 18, line: 1 },
+        },
+      },
+      expression: false,
+      generator: true,
+      id: Identifier {
+        type: "Identifier",
+        name: "foo",
+
+        range: [10, 13],
+        loc: {
+          start: { column: 10, line: 1 },
+          end: { column: 13, line: 1 },
+        },
+      },
+      params: Array [],
+
+      range: [0, 18],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 18, line: 1 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 19],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/generator/snapshots/4-Babel-Tokens.shot b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/generator/snapshots/4-Babel-Tokens.shot
new file mode 100644
index 000000000000..3fb7fa84513a
--- /dev/null
+++ b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/generator/snapshots/4-Babel-Tokens.shot
@@ -0,0 +1,76 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration FunctionDeclaration generator Babel - Tokens 1`] = `
+Array [
+  Keyword {
+    type: "Keyword",
+    value: "function",
+
+    range: [0, 8],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 8, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "*",
+
+    range: [8, 9],
+    loc: {
+      start: { column: 8, line: 1 },
+      end: { column: 9, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "foo",
+
+    range: [10, 13],
+    loc: {
+      start: { column: 10, line: 1 },
+      end: { column: 13, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "(",
+
+    range: [13, 14],
+    loc: {
+      start: { column: 13, line: 1 },
+      end: { column: 14, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ")",
+
+    range: [14, 15],
+    loc: {
+      start: { column: 14, line: 1 },
+      end: { column: 15, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "{",
+
+    range: [16, 17],
+    loc: {
+      start: { column: 16, line: 1 },
+      end: { column: 17, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "}",
+
+    range: [17, 18],
+    loc: {
+      start: { column: 17, line: 1 },
+      end: { column: 18, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/decoratorOne/snapshots/5-AST-Alignment-AST.shot b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/generator/snapshots/5-AST-Alignment-AST.shot
similarity index 67%
rename from packages/ast-spec/src/declaration/ClassDeclaration/fixtures/decoratorOne/snapshots/5-AST-Alignment-AST.shot
rename to packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/generator/snapshots/5-AST-Alignment-AST.shot
index 19b8f62ee26d..e94e87d038a4 100644
--- a/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/decoratorOne/snapshots/5-AST-Alignment-AST.shot
+++ b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/generator/snapshots/5-AST-Alignment-AST.shot
@@ -1,6 +1,6 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
-exports[`AST Fixtures declaration ClassDeclaration decoratorOne AST Alignment - AST 1`] = `
+exports[`AST Fixtures declaration FunctionDeclaration generator AST Alignment - AST 1`] = `
 "Snapshot Diff:
 Compared values have no visual difference."
 `;
diff --git a/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/decoratorOne/snapshots/6-AST-Alignment-Tokens.shot b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/generator/snapshots/6-AST-Alignment-Tokens.shot
similarity index 68%
rename from packages/ast-spec/src/declaration/ClassDeclaration/fixtures/decoratorOne/snapshots/6-AST-Alignment-Tokens.shot
rename to packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/generator/snapshots/6-AST-Alignment-Tokens.shot
index 915fd1d51f92..033a7496b3cb 100644
--- a/packages/ast-spec/src/declaration/ClassDeclaration/fixtures/decoratorOne/snapshots/6-AST-Alignment-Tokens.shot
+++ b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/generator/snapshots/6-AST-Alignment-Tokens.shot
@@ -1,6 +1,6 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
-exports[`AST Fixtures declaration ClassDeclaration decoratorOne AST Alignment - Token 1`] = `
+exports[`AST Fixtures declaration FunctionDeclaration generator AST Alignment - Token 1`] = `
 "Snapshot Diff:
 Compared values have no visual difference."
 `;
diff --git a/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/param-many/fixture.ts b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/param-many/fixture.ts
new file mode 100644
index 000000000000..8dca93172ea8
--- /dev/null
+++ b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/param-many/fixture.ts
@@ -0,0 +1 @@
+function foo(a, b, c) {}
diff --git a/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/param-many/snapshots/1-TSESTree-AST.shot b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/param-many/snapshots/1-TSESTree-AST.shot
new file mode 100644
index 000000000000..9a6db3d1c4c8
--- /dev/null
+++ b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/param-many/snapshots/1-TSESTree-AST.shot
@@ -0,0 +1,80 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration FunctionDeclaration param-many TSESTree - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    FunctionDeclaration {
+      type: "FunctionDeclaration",
+      async: false,
+      body: BlockStatement {
+        type: "BlockStatement",
+        body: Array [],
+
+        range: [22, 24],
+        loc: {
+          start: { column: 22, line: 1 },
+          end: { column: 24, line: 1 },
+        },
+      },
+      expression: false,
+      generator: false,
+      id: Identifier {
+        type: "Identifier",
+        name: "foo",
+
+        range: [9, 12],
+        loc: {
+          start: { column: 9, line: 1 },
+          end: { column: 12, line: 1 },
+        },
+      },
+      params: Array [
+        Identifier {
+          type: "Identifier",
+          name: "a",
+
+          range: [13, 14],
+          loc: {
+            start: { column: 13, line: 1 },
+            end: { column: 14, line: 1 },
+          },
+        },
+        Identifier {
+          type: "Identifier",
+          name: "b",
+
+          range: [16, 17],
+          loc: {
+            start: { column: 16, line: 1 },
+            end: { column: 17, line: 1 },
+          },
+        },
+        Identifier {
+          type: "Identifier",
+          name: "c",
+
+          range: [19, 20],
+          loc: {
+            start: { column: 19, line: 1 },
+            end: { column: 20, line: 1 },
+          },
+        },
+      ],
+
+      range: [0, 24],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 24, line: 1 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 25],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/param-many/snapshots/2-TSESTree-Tokens.shot b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/param-many/snapshots/2-TSESTree-Tokens.shot
new file mode 100644
index 000000000000..08de97f6423d
--- /dev/null
+++ b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/param-many/snapshots/2-TSESTree-Tokens.shot
@@ -0,0 +1,116 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration FunctionDeclaration param-many TSESTree - Tokens 1`] = `
+Array [
+  Keyword {
+    type: "Keyword",
+    value: "function",
+
+    range: [0, 8],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 8, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "foo",
+
+    range: [9, 12],
+    loc: {
+      start: { column: 9, line: 1 },
+      end: { column: 12, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "(",
+
+    range: [12, 13],
+    loc: {
+      start: { column: 12, line: 1 },
+      end: { column: 13, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "a",
+
+    range: [13, 14],
+    loc: {
+      start: { column: 13, line: 1 },
+      end: { column: 14, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ",",
+
+    range: [14, 15],
+    loc: {
+      start: { column: 14, line: 1 },
+      end: { column: 15, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "b",
+
+    range: [16, 17],
+    loc: {
+      start: { column: 16, line: 1 },
+      end: { column: 17, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ",",
+
+    range: [17, 18],
+    loc: {
+      start: { column: 17, line: 1 },
+      end: { column: 18, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "c",
+
+    range: [19, 20],
+    loc: {
+      start: { column: 19, line: 1 },
+      end: { column: 20, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ")",
+
+    range: [20, 21],
+    loc: {
+      start: { column: 20, line: 1 },
+      end: { column: 21, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "{",
+
+    range: [22, 23],
+    loc: {
+      start: { column: 22, line: 1 },
+      end: { column: 23, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "}",
+
+    range: [23, 24],
+    loc: {
+      start: { column: 23, line: 1 },
+      end: { column: 24, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/param-many/snapshots/3-Babel-AST.shot b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/param-many/snapshots/3-Babel-AST.shot
new file mode 100644
index 000000000000..c04ed8242841
--- /dev/null
+++ b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/param-many/snapshots/3-Babel-AST.shot
@@ -0,0 +1,80 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration FunctionDeclaration param-many Babel - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    FunctionDeclaration {
+      type: "FunctionDeclaration",
+      async: false,
+      body: BlockStatement {
+        type: "BlockStatement",
+        body: Array [],
+
+        range: [22, 24],
+        loc: {
+          start: { column: 22, line: 1 },
+          end: { column: 24, line: 1 },
+        },
+      },
+      expression: false,
+      generator: false,
+      id: Identifier {
+        type: "Identifier",
+        name: "foo",
+
+        range: [9, 12],
+        loc: {
+          start: { column: 9, line: 1 },
+          end: { column: 12, line: 1 },
+        },
+      },
+      params: Array [
+        Identifier {
+          type: "Identifier",
+          name: "a",
+
+          range: [13, 14],
+          loc: {
+            start: { column: 13, line: 1 },
+            end: { column: 14, line: 1 },
+          },
+        },
+        Identifier {
+          type: "Identifier",
+          name: "b",
+
+          range: [16, 17],
+          loc: {
+            start: { column: 16, line: 1 },
+            end: { column: 17, line: 1 },
+          },
+        },
+        Identifier {
+          type: "Identifier",
+          name: "c",
+
+          range: [19, 20],
+          loc: {
+            start: { column: 19, line: 1 },
+            end: { column: 20, line: 1 },
+          },
+        },
+      ],
+
+      range: [0, 24],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 24, line: 1 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 25],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/param-many/snapshots/4-Babel-Tokens.shot b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/param-many/snapshots/4-Babel-Tokens.shot
new file mode 100644
index 000000000000..a0aa44879941
--- /dev/null
+++ b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/param-many/snapshots/4-Babel-Tokens.shot
@@ -0,0 +1,116 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration FunctionDeclaration param-many Babel - Tokens 1`] = `
+Array [
+  Keyword {
+    type: "Keyword",
+    value: "function",
+
+    range: [0, 8],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 8, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "foo",
+
+    range: [9, 12],
+    loc: {
+      start: { column: 9, line: 1 },
+      end: { column: 12, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "(",
+
+    range: [12, 13],
+    loc: {
+      start: { column: 12, line: 1 },
+      end: { column: 13, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "a",
+
+    range: [13, 14],
+    loc: {
+      start: { column: 13, line: 1 },
+      end: { column: 14, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ",",
+
+    range: [14, 15],
+    loc: {
+      start: { column: 14, line: 1 },
+      end: { column: 15, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "b",
+
+    range: [16, 17],
+    loc: {
+      start: { column: 16, line: 1 },
+      end: { column: 17, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ",",
+
+    range: [17, 18],
+    loc: {
+      start: { column: 17, line: 1 },
+      end: { column: 18, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "c",
+
+    range: [19, 20],
+    loc: {
+      start: { column: 19, line: 1 },
+      end: { column: 20, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ")",
+
+    range: [20, 21],
+    loc: {
+      start: { column: 20, line: 1 },
+      end: { column: 21, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "{",
+
+    range: [22, 23],
+    loc: {
+      start: { column: 22, line: 1 },
+      end: { column: 23, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "}",
+
+    range: [23, 24],
+    loc: {
+      start: { column: 23, line: 1 },
+      end: { column: 24, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/param-many/snapshots/5-AST-Alignment-AST.shot b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/param-many/snapshots/5-AST-Alignment-AST.shot
new file mode 100644
index 000000000000..f8b80c46b1e6
--- /dev/null
+++ b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/param-many/snapshots/5-AST-Alignment-AST.shot
@@ -0,0 +1,6 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration FunctionDeclaration param-many AST Alignment - AST 1`] = `
+"Snapshot Diff:
+Compared values have no visual difference."
+`;
diff --git a/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/param-many/snapshots/6-AST-Alignment-Tokens.shot b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/param-many/snapshots/6-AST-Alignment-Tokens.shot
new file mode 100644
index 000000000000..70640eb186a9
--- /dev/null
+++ b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/param-many/snapshots/6-AST-Alignment-Tokens.shot
@@ -0,0 +1,6 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration FunctionDeclaration param-many AST Alignment - Token 1`] = `
+"Snapshot Diff:
+Compared values have no visual difference."
+`;
diff --git a/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/param-one/fixture.ts b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/param-one/fixture.ts
new file mode 100644
index 000000000000..ef1dd099d3f1
--- /dev/null
+++ b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/param-one/fixture.ts
@@ -0,0 +1 @@
+function foo(a) {}
diff --git a/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/param-one/snapshots/1-TSESTree-AST.shot b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/param-one/snapshots/1-TSESTree-AST.shot
new file mode 100644
index 000000000000..99d9cdc9e989
--- /dev/null
+++ b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/param-one/snapshots/1-TSESTree-AST.shot
@@ -0,0 +1,60 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration FunctionDeclaration param-one TSESTree - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    FunctionDeclaration {
+      type: "FunctionDeclaration",
+      async: false,
+      body: BlockStatement {
+        type: "BlockStatement",
+        body: Array [],
+
+        range: [16, 18],
+        loc: {
+          start: { column: 16, line: 1 },
+          end: { column: 18, line: 1 },
+        },
+      },
+      expression: false,
+      generator: false,
+      id: Identifier {
+        type: "Identifier",
+        name: "foo",
+
+        range: [9, 12],
+        loc: {
+          start: { column: 9, line: 1 },
+          end: { column: 12, line: 1 },
+        },
+      },
+      params: Array [
+        Identifier {
+          type: "Identifier",
+          name: "a",
+
+          range: [13, 14],
+          loc: {
+            start: { column: 13, line: 1 },
+            end: { column: 14, line: 1 },
+          },
+        },
+      ],
+
+      range: [0, 18],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 18, line: 1 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 19],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/param-one/snapshots/2-TSESTree-Tokens.shot b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/param-one/snapshots/2-TSESTree-Tokens.shot
new file mode 100644
index 000000000000..81f8b5dc7518
--- /dev/null
+++ b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/param-one/snapshots/2-TSESTree-Tokens.shot
@@ -0,0 +1,76 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration FunctionDeclaration param-one TSESTree - Tokens 1`] = `
+Array [
+  Keyword {
+    type: "Keyword",
+    value: "function",
+
+    range: [0, 8],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 8, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "foo",
+
+    range: [9, 12],
+    loc: {
+      start: { column: 9, line: 1 },
+      end: { column: 12, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "(",
+
+    range: [12, 13],
+    loc: {
+      start: { column: 12, line: 1 },
+      end: { column: 13, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "a",
+
+    range: [13, 14],
+    loc: {
+      start: { column: 13, line: 1 },
+      end: { column: 14, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ")",
+
+    range: [14, 15],
+    loc: {
+      start: { column: 14, line: 1 },
+      end: { column: 15, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "{",
+
+    range: [16, 17],
+    loc: {
+      start: { column: 16, line: 1 },
+      end: { column: 17, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "}",
+
+    range: [17, 18],
+    loc: {
+      start: { column: 17, line: 1 },
+      end: { column: 18, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/param-one/snapshots/3-Babel-AST.shot b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/param-one/snapshots/3-Babel-AST.shot
new file mode 100644
index 000000000000..6e503e760fb6
--- /dev/null
+++ b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/param-one/snapshots/3-Babel-AST.shot
@@ -0,0 +1,60 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration FunctionDeclaration param-one Babel - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    FunctionDeclaration {
+      type: "FunctionDeclaration",
+      async: false,
+      body: BlockStatement {
+        type: "BlockStatement",
+        body: Array [],
+
+        range: [16, 18],
+        loc: {
+          start: { column: 16, line: 1 },
+          end: { column: 18, line: 1 },
+        },
+      },
+      expression: false,
+      generator: false,
+      id: Identifier {
+        type: "Identifier",
+        name: "foo",
+
+        range: [9, 12],
+        loc: {
+          start: { column: 9, line: 1 },
+          end: { column: 12, line: 1 },
+        },
+      },
+      params: Array [
+        Identifier {
+          type: "Identifier",
+          name: "a",
+
+          range: [13, 14],
+          loc: {
+            start: { column: 13, line: 1 },
+            end: { column: 14, line: 1 },
+          },
+        },
+      ],
+
+      range: [0, 18],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 18, line: 1 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 19],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/param-one/snapshots/4-Babel-Tokens.shot b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/param-one/snapshots/4-Babel-Tokens.shot
new file mode 100644
index 000000000000..802761abb0ee
--- /dev/null
+++ b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/param-one/snapshots/4-Babel-Tokens.shot
@@ -0,0 +1,76 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration FunctionDeclaration param-one Babel - Tokens 1`] = `
+Array [
+  Keyword {
+    type: "Keyword",
+    value: "function",
+
+    range: [0, 8],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 8, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "foo",
+
+    range: [9, 12],
+    loc: {
+      start: { column: 9, line: 1 },
+      end: { column: 12, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "(",
+
+    range: [12, 13],
+    loc: {
+      start: { column: 12, line: 1 },
+      end: { column: 13, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "a",
+
+    range: [13, 14],
+    loc: {
+      start: { column: 13, line: 1 },
+      end: { column: 14, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ")",
+
+    range: [14, 15],
+    loc: {
+      start: { column: 14, line: 1 },
+      end: { column: 15, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "{",
+
+    range: [16, 17],
+    loc: {
+      start: { column: 16, line: 1 },
+      end: { column: 17, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "}",
+
+    range: [17, 18],
+    loc: {
+      start: { column: 17, line: 1 },
+      end: { column: 18, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/param-one/snapshots/5-AST-Alignment-AST.shot b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/param-one/snapshots/5-AST-Alignment-AST.shot
new file mode 100644
index 000000000000..5c75a74de72a
--- /dev/null
+++ b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/param-one/snapshots/5-AST-Alignment-AST.shot
@@ -0,0 +1,6 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration FunctionDeclaration param-one AST Alignment - AST 1`] = `
+"Snapshot Diff:
+Compared values have no visual difference."
+`;
diff --git a/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/param-one/snapshots/6-AST-Alignment-Tokens.shot b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/param-one/snapshots/6-AST-Alignment-Tokens.shot
new file mode 100644
index 000000000000..f6f408e32c2c
--- /dev/null
+++ b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/param-one/snapshots/6-AST-Alignment-Tokens.shot
@@ -0,0 +1,6 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration FunctionDeclaration param-one AST Alignment - Token 1`] = `
+"Snapshot Diff:
+Compared values have no visual difference."
+`;
diff --git a/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/returnType/fixture.ts b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/returnType/fixture.ts
new file mode 100644
index 000000000000..4fa04cdbc0b2
--- /dev/null
+++ b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/returnType/fixture.ts
@@ -0,0 +1 @@
+function foo(): void {}
diff --git a/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/returnType/snapshots/1-TSESTree-AST.shot b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/returnType/snapshots/1-TSESTree-AST.shot
new file mode 100644
index 000000000000..d9d3eccf8d7f
--- /dev/null
+++ b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/returnType/snapshots/1-TSESTree-AST.shot
@@ -0,0 +1,67 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration FunctionDeclaration returnType TSESTree - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    FunctionDeclaration {
+      type: "FunctionDeclaration",
+      async: false,
+      body: BlockStatement {
+        type: "BlockStatement",
+        body: Array [],
+
+        range: [21, 23],
+        loc: {
+          start: { column: 21, line: 1 },
+          end: { column: 23, line: 1 },
+        },
+      },
+      expression: false,
+      generator: false,
+      id: Identifier {
+        type: "Identifier",
+        name: "foo",
+
+        range: [9, 12],
+        loc: {
+          start: { column: 9, line: 1 },
+          end: { column: 12, line: 1 },
+        },
+      },
+      params: Array [],
+      returnType: TSTypeAnnotation {
+        type: "TSTypeAnnotation",
+        typeAnnotation: TSVoidKeyword {
+          type: "TSVoidKeyword",
+
+          range: [16, 20],
+          loc: {
+            start: { column: 16, line: 1 },
+            end: { column: 20, line: 1 },
+          },
+        },
+
+        range: [14, 20],
+        loc: {
+          start: { column: 14, line: 1 },
+          end: { column: 20, line: 1 },
+        },
+      },
+
+      range: [0, 23],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 23, line: 1 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 24],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/returnType/snapshots/2-TSESTree-Tokens.shot b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/returnType/snapshots/2-TSESTree-Tokens.shot
new file mode 100644
index 000000000000..d3930ccf8dcf
--- /dev/null
+++ b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/returnType/snapshots/2-TSESTree-Tokens.shot
@@ -0,0 +1,86 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration FunctionDeclaration returnType TSESTree - Tokens 1`] = `
+Array [
+  Keyword {
+    type: "Keyword",
+    value: "function",
+
+    range: [0, 8],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 8, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "foo",
+
+    range: [9, 12],
+    loc: {
+      start: { column: 9, line: 1 },
+      end: { column: 12, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "(",
+
+    range: [12, 13],
+    loc: {
+      start: { column: 12, line: 1 },
+      end: { column: 13, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ")",
+
+    range: [13, 14],
+    loc: {
+      start: { column: 13, line: 1 },
+      end: { column: 14, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ":",
+
+    range: [14, 15],
+    loc: {
+      start: { column: 14, line: 1 },
+      end: { column: 15, line: 1 },
+    },
+  },
+  Keyword {
+    type: "Keyword",
+    value: "void",
+
+    range: [16, 20],
+    loc: {
+      start: { column: 16, line: 1 },
+      end: { column: 20, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "{",
+
+    range: [21, 22],
+    loc: {
+      start: { column: 21, line: 1 },
+      end: { column: 22, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "}",
+
+    range: [22, 23],
+    loc: {
+      start: { column: 22, line: 1 },
+      end: { column: 23, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/returnType/snapshots/3-Babel-AST.shot b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/returnType/snapshots/3-Babel-AST.shot
new file mode 100644
index 000000000000..8f9c235c4292
--- /dev/null
+++ b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/returnType/snapshots/3-Babel-AST.shot
@@ -0,0 +1,67 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration FunctionDeclaration returnType Babel - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    FunctionDeclaration {
+      type: "FunctionDeclaration",
+      async: false,
+      body: BlockStatement {
+        type: "BlockStatement",
+        body: Array [],
+
+        range: [21, 23],
+        loc: {
+          start: { column: 21, line: 1 },
+          end: { column: 23, line: 1 },
+        },
+      },
+      expression: false,
+      generator: false,
+      id: Identifier {
+        type: "Identifier",
+        name: "foo",
+
+        range: [9, 12],
+        loc: {
+          start: { column: 9, line: 1 },
+          end: { column: 12, line: 1 },
+        },
+      },
+      params: Array [],
+      returnType: TSTypeAnnotation {
+        type: "TSTypeAnnotation",
+        typeAnnotation: TSVoidKeyword {
+          type: "TSVoidKeyword",
+
+          range: [16, 20],
+          loc: {
+            start: { column: 16, line: 1 },
+            end: { column: 20, line: 1 },
+          },
+        },
+
+        range: [14, 20],
+        loc: {
+          start: { column: 14, line: 1 },
+          end: { column: 20, line: 1 },
+        },
+      },
+
+      range: [0, 23],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 23, line: 1 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 24],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/returnType/snapshots/4-Babel-Tokens.shot b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/returnType/snapshots/4-Babel-Tokens.shot
new file mode 100644
index 000000000000..0c94d7108ae4
--- /dev/null
+++ b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/returnType/snapshots/4-Babel-Tokens.shot
@@ -0,0 +1,86 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration FunctionDeclaration returnType Babel - Tokens 1`] = `
+Array [
+  Keyword {
+    type: "Keyword",
+    value: "function",
+
+    range: [0, 8],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 8, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "foo",
+
+    range: [9, 12],
+    loc: {
+      start: { column: 9, line: 1 },
+      end: { column: 12, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "(",
+
+    range: [12, 13],
+    loc: {
+      start: { column: 12, line: 1 },
+      end: { column: 13, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ")",
+
+    range: [13, 14],
+    loc: {
+      start: { column: 13, line: 1 },
+      end: { column: 14, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ":",
+
+    range: [14, 15],
+    loc: {
+      start: { column: 14, line: 1 },
+      end: { column: 15, line: 1 },
+    },
+  },
+  Keyword {
+    type: "Keyword",
+    value: "void",
+
+    range: [16, 20],
+    loc: {
+      start: { column: 16, line: 1 },
+      end: { column: 20, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "{",
+
+    range: [21, 22],
+    loc: {
+      start: { column: 21, line: 1 },
+      end: { column: 22, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "}",
+
+    range: [22, 23],
+    loc: {
+      start: { column: 22, line: 1 },
+      end: { column: 23, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/returnType/snapshots/5-AST-Alignment-AST.shot b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/returnType/snapshots/5-AST-Alignment-AST.shot
new file mode 100644
index 000000000000..d0df21058e9f
--- /dev/null
+++ b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/returnType/snapshots/5-AST-Alignment-AST.shot
@@ -0,0 +1,6 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration FunctionDeclaration returnType AST Alignment - AST 1`] = `
+"Snapshot Diff:
+Compared values have no visual difference."
+`;
diff --git a/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/returnType/snapshots/6-AST-Alignment-Tokens.shot b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/returnType/snapshots/6-AST-Alignment-Tokens.shot
new file mode 100644
index 000000000000..0a4b02ae4245
--- /dev/null
+++ b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/returnType/snapshots/6-AST-Alignment-Tokens.shot
@@ -0,0 +1,6 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration FunctionDeclaration returnType AST Alignment - Token 1`] = `
+"Snapshot Diff:
+Compared values have no visual difference."
+`;
diff --git a/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/type-param-many/fixture.ts b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/type-param-many/fixture.ts
new file mode 100644
index 000000000000..36ddc225d14c
--- /dev/null
+++ b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/type-param-many/fixture.ts
@@ -0,0 +1 @@
+function foo<T, U, V>() {}
diff --git a/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/type-param-many/snapshots/1-TSESTree-AST.shot b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/type-param-many/snapshots/1-TSESTree-AST.shot
new file mode 100644
index 000000000000..24eae0d32901
--- /dev/null
+++ b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/type-param-many/snapshots/1-TSESTree-AST.shot
@@ -0,0 +1,123 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration FunctionDeclaration type-param-many TSESTree - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    FunctionDeclaration {
+      type: "FunctionDeclaration",
+      async: false,
+      body: BlockStatement {
+        type: "BlockStatement",
+        body: Array [],
+
+        range: [24, 26],
+        loc: {
+          start: { column: 24, line: 1 },
+          end: { column: 26, line: 1 },
+        },
+      },
+      expression: false,
+      generator: false,
+      id: Identifier {
+        type: "Identifier",
+        name: "foo",
+
+        range: [9, 12],
+        loc: {
+          start: { column: 9, line: 1 },
+          end: { column: 12, line: 1 },
+        },
+      },
+      params: Array [],
+      typeParameters: TSTypeParameterDeclaration {
+        type: "TSTypeParameterDeclaration",
+        params: Array [
+          TSTypeParameter {
+            type: "TSTypeParameter",
+            in: false,
+            name: Identifier {
+              type: "Identifier",
+              name: "T",
+
+              range: [13, 14],
+              loc: {
+                start: { column: 13, line: 1 },
+                end: { column: 14, line: 1 },
+              },
+            },
+            out: false,
+
+            range: [13, 14],
+            loc: {
+              start: { column: 13, line: 1 },
+              end: { column: 14, line: 1 },
+            },
+          },
+          TSTypeParameter {
+            type: "TSTypeParameter",
+            in: false,
+            name: Identifier {
+              type: "Identifier",
+              name: "U",
+
+              range: [16, 17],
+              loc: {
+                start: { column: 16, line: 1 },
+                end: { column: 17, line: 1 },
+              },
+            },
+            out: false,
+
+            range: [16, 17],
+            loc: {
+              start: { column: 16, line: 1 },
+              end: { column: 17, line: 1 },
+            },
+          },
+          TSTypeParameter {
+            type: "TSTypeParameter",
+            in: false,
+            name: Identifier {
+              type: "Identifier",
+              name: "V",
+
+              range: [19, 20],
+              loc: {
+                start: { column: 19, line: 1 },
+                end: { column: 20, line: 1 },
+              },
+            },
+            out: false,
+
+            range: [19, 20],
+            loc: {
+              start: { column: 19, line: 1 },
+              end: { column: 20, line: 1 },
+            },
+          },
+        ],
+
+        range: [12, 21],
+        loc: {
+          start: { column: 12, line: 1 },
+          end: { column: 21, line: 1 },
+        },
+      },
+
+      range: [0, 26],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 26, line: 1 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 27],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/type-param-many/snapshots/2-TSESTree-Tokens.shot b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/type-param-many/snapshots/2-TSESTree-Tokens.shot
new file mode 100644
index 000000000000..99504b183408
--- /dev/null
+++ b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/type-param-many/snapshots/2-TSESTree-Tokens.shot
@@ -0,0 +1,136 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration FunctionDeclaration type-param-many TSESTree - Tokens 1`] = `
+Array [
+  Keyword {
+    type: "Keyword",
+    value: "function",
+
+    range: [0, 8],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 8, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "foo",
+
+    range: [9, 12],
+    loc: {
+      start: { column: 9, line: 1 },
+      end: { column: 12, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "<",
+
+    range: [12, 13],
+    loc: {
+      start: { column: 12, line: 1 },
+      end: { column: 13, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "T",
+
+    range: [13, 14],
+    loc: {
+      start: { column: 13, line: 1 },
+      end: { column: 14, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ",",
+
+    range: [14, 15],
+    loc: {
+      start: { column: 14, line: 1 },
+      end: { column: 15, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "U",
+
+    range: [16, 17],
+    loc: {
+      start: { column: 16, line: 1 },
+      end: { column: 17, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ",",
+
+    range: [17, 18],
+    loc: {
+      start: { column: 17, line: 1 },
+      end: { column: 18, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "V",
+
+    range: [19, 20],
+    loc: {
+      start: { column: 19, line: 1 },
+      end: { column: 20, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ">",
+
+    range: [20, 21],
+    loc: {
+      start: { column: 20, line: 1 },
+      end: { column: 21, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "(",
+
+    range: [21, 22],
+    loc: {
+      start: { column: 21, line: 1 },
+      end: { column: 22, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ")",
+
+    range: [22, 23],
+    loc: {
+      start: { column: 22, line: 1 },
+      end: { column: 23, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "{",
+
+    range: [24, 25],
+    loc: {
+      start: { column: 24, line: 1 },
+      end: { column: 25, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "}",
+
+    range: [25, 26],
+    loc: {
+      start: { column: 25, line: 1 },
+      end: { column: 26, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/type-param-many/snapshots/3-Babel-AST.shot b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/type-param-many/snapshots/3-Babel-AST.shot
new file mode 100644
index 000000000000..690e6d4036ba
--- /dev/null
+++ b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/type-param-many/snapshots/3-Babel-AST.shot
@@ -0,0 +1,90 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration FunctionDeclaration type-param-many Babel - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    FunctionDeclaration {
+      type: "FunctionDeclaration",
+      async: false,
+      body: BlockStatement {
+        type: "BlockStatement",
+        body: Array [],
+
+        range: [24, 26],
+        loc: {
+          start: { column: 24, line: 1 },
+          end: { column: 26, line: 1 },
+        },
+      },
+      expression: false,
+      generator: false,
+      id: Identifier {
+        type: "Identifier",
+        name: "foo",
+
+        range: [9, 12],
+        loc: {
+          start: { column: 9, line: 1 },
+          end: { column: 12, line: 1 },
+        },
+      },
+      params: Array [],
+      typeParameters: TSTypeParameterDeclaration {
+        type: "TSTypeParameterDeclaration",
+        params: Array [
+          TSTypeParameter {
+            type: "TSTypeParameter",
+            name: "T",
+
+            range: [13, 14],
+            loc: {
+              start: { column: 13, line: 1 },
+              end: { column: 14, line: 1 },
+            },
+          },
+          TSTypeParameter {
+            type: "TSTypeParameter",
+            name: "U",
+
+            range: [16, 17],
+            loc: {
+              start: { column: 16, line: 1 },
+              end: { column: 17, line: 1 },
+            },
+          },
+          TSTypeParameter {
+            type: "TSTypeParameter",
+            name: "V",
+
+            range: [19, 20],
+            loc: {
+              start: { column: 19, line: 1 },
+              end: { column: 20, line: 1 },
+            },
+          },
+        ],
+
+        range: [12, 21],
+        loc: {
+          start: { column: 12, line: 1 },
+          end: { column: 21, line: 1 },
+        },
+      },
+
+      range: [0, 26],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 26, line: 1 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 27],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/type-param-many/snapshots/4-Babel-Tokens.shot b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/type-param-many/snapshots/4-Babel-Tokens.shot
new file mode 100644
index 000000000000..b7e57a6f4045
--- /dev/null
+++ b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/type-param-many/snapshots/4-Babel-Tokens.shot
@@ -0,0 +1,136 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration FunctionDeclaration type-param-many Babel - Tokens 1`] = `
+Array [
+  Keyword {
+    type: "Keyword",
+    value: "function",
+
+    range: [0, 8],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 8, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "foo",
+
+    range: [9, 12],
+    loc: {
+      start: { column: 9, line: 1 },
+      end: { column: 12, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "<",
+
+    range: [12, 13],
+    loc: {
+      start: { column: 12, line: 1 },
+      end: { column: 13, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "T",
+
+    range: [13, 14],
+    loc: {
+      start: { column: 13, line: 1 },
+      end: { column: 14, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ",",
+
+    range: [14, 15],
+    loc: {
+      start: { column: 14, line: 1 },
+      end: { column: 15, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "U",
+
+    range: [16, 17],
+    loc: {
+      start: { column: 16, line: 1 },
+      end: { column: 17, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ",",
+
+    range: [17, 18],
+    loc: {
+      start: { column: 17, line: 1 },
+      end: { column: 18, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "V",
+
+    range: [19, 20],
+    loc: {
+      start: { column: 19, line: 1 },
+      end: { column: 20, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ">",
+
+    range: [20, 21],
+    loc: {
+      start: { column: 20, line: 1 },
+      end: { column: 21, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "(",
+
+    range: [21, 22],
+    loc: {
+      start: { column: 21, line: 1 },
+      end: { column: 22, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ")",
+
+    range: [22, 23],
+    loc: {
+      start: { column: 22, line: 1 },
+      end: { column: 23, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "{",
+
+    range: [24, 25],
+    loc: {
+      start: { column: 24, line: 1 },
+      end: { column: 25, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "}",
+
+    range: [25, 26],
+    loc: {
+      start: { column: 25, line: 1 },
+      end: { column: 26, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/type-param-many/snapshots/5-AST-Alignment-AST.shot b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/type-param-many/snapshots/5-AST-Alignment-AST.shot
new file mode 100644
index 000000000000..98ace90820fb
--- /dev/null
+++ b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/type-param-many/snapshots/5-AST-Alignment-AST.shot
@@ -0,0 +1,130 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration FunctionDeclaration type-param-many AST Alignment - AST 1`] = `
+"Snapshot Diff:
+- TSESTree
++ Babel
+
+  Program {
+    type: 'Program',
+    body: Array [
+      FunctionDeclaration {
+        type: 'FunctionDeclaration',
+        async: false,
+        body: BlockStatement {
+          type: 'BlockStatement',
+          body: Array [],
+
+          range: [24, 26],
+          loc: {
+            start: { column: 24, line: 1 },
+            end: { column: 26, line: 1 },
+          },
+        },
+        expression: false,
+        generator: false,
+        id: Identifier {
+          type: 'Identifier',
+          name: 'foo',
+
+          range: [9, 12],
+          loc: {
+            start: { column: 9, line: 1 },
+            end: { column: 12, line: 1 },
+          },
+        },
+        params: Array [],
+        typeParameters: TSTypeParameterDeclaration {
+          type: 'TSTypeParameterDeclaration',
+          params: Array [
+            TSTypeParameter {
+              type: 'TSTypeParameter',
+-             in: false,
+-             name: Identifier {
+-               type: 'Identifier',
+-               name: 'T',
+-
+-               range: [13, 14],
+-               loc: {
+-                 start: { column: 13, line: 1 },
+-                 end: { column: 14, line: 1 },
+-               },
+-             },
+-             out: false,
++             name: 'T',
+
+              range: [13, 14],
+              loc: {
+                start: { column: 13, line: 1 },
+                end: { column: 14, line: 1 },
+              },
+            },
+            TSTypeParameter {
+              type: 'TSTypeParameter',
+-             in: false,
+-             name: Identifier {
+-               type: 'Identifier',
+-               name: 'U',
+-
+-               range: [16, 17],
+-               loc: {
+-                 start: { column: 16, line: 1 },
+-                 end: { column: 17, line: 1 },
+-               },
+-             },
+-             out: false,
++             name: 'U',
+
+              range: [16, 17],
+              loc: {
+                start: { column: 16, line: 1 },
+                end: { column: 17, line: 1 },
+              },
+            },
+            TSTypeParameter {
+              type: 'TSTypeParameter',
+-             in: false,
+-             name: Identifier {
+-               type: 'Identifier',
+-               name: 'V',
+-
+-               range: [19, 20],
+-               loc: {
+-                 start: { column: 19, line: 1 },
+-                 end: { column: 20, line: 1 },
+-               },
+-             },
+-             out: false,
++             name: 'V',
+
+              range: [19, 20],
+              loc: {
+                start: { column: 19, line: 1 },
+                end: { column: 20, line: 1 },
+              },
+            },
+          ],
+
+          range: [12, 21],
+          loc: {
+            start: { column: 12, line: 1 },
+            end: { column: 21, line: 1 },
+          },
+        },
+
+        range: [0, 26],
+        loc: {
+          start: { column: 0, line: 1 },
+          end: { column: 26, line: 1 },
+        },
+      },
+    ],
+    sourceType: 'script',
+
+    range: [0, 27],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 0, line: 2 },
+    },
+  }"
+`;
diff --git a/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/type-param-many/snapshots/6-AST-Alignment-Tokens.shot b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/type-param-many/snapshots/6-AST-Alignment-Tokens.shot
new file mode 100644
index 000000000000..af00d0fb8523
--- /dev/null
+++ b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/type-param-many/snapshots/6-AST-Alignment-Tokens.shot
@@ -0,0 +1,6 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration FunctionDeclaration type-param-many AST Alignment - Token 1`] = `
+"Snapshot Diff:
+Compared values have no visual difference."
+`;
diff --git a/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/type-param-one/fixture.ts b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/type-param-one/fixture.ts
new file mode 100644
index 000000000000..7994e752aa81
--- /dev/null
+++ b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/type-param-one/fixture.ts
@@ -0,0 +1 @@
+function foo<T>() {}
diff --git a/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/type-param-one/snapshots/1-TSESTree-AST.shot b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/type-param-one/snapshots/1-TSESTree-AST.shot
new file mode 100644
index 000000000000..b2caab0f05b8
--- /dev/null
+++ b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/type-param-one/snapshots/1-TSESTree-AST.shot
@@ -0,0 +1,81 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration FunctionDeclaration type-param-one TSESTree - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    FunctionDeclaration {
+      type: "FunctionDeclaration",
+      async: false,
+      body: BlockStatement {
+        type: "BlockStatement",
+        body: Array [],
+
+        range: [18, 20],
+        loc: {
+          start: { column: 18, line: 1 },
+          end: { column: 20, line: 1 },
+        },
+      },
+      expression: false,
+      generator: false,
+      id: Identifier {
+        type: "Identifier",
+        name: "foo",
+
+        range: [9, 12],
+        loc: {
+          start: { column: 9, line: 1 },
+          end: { column: 12, line: 1 },
+        },
+      },
+      params: Array [],
+      typeParameters: TSTypeParameterDeclaration {
+        type: "TSTypeParameterDeclaration",
+        params: Array [
+          TSTypeParameter {
+            type: "TSTypeParameter",
+            in: false,
+            name: Identifier {
+              type: "Identifier",
+              name: "T",
+
+              range: [13, 14],
+              loc: {
+                start: { column: 13, line: 1 },
+                end: { column: 14, line: 1 },
+              },
+            },
+            out: false,
+
+            range: [13, 14],
+            loc: {
+              start: { column: 13, line: 1 },
+              end: { column: 14, line: 1 },
+            },
+          },
+        ],
+
+        range: [12, 15],
+        loc: {
+          start: { column: 12, line: 1 },
+          end: { column: 15, line: 1 },
+        },
+      },
+
+      range: [0, 20],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 20, line: 1 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 21],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/type-param-one/snapshots/2-TSESTree-Tokens.shot b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/type-param-one/snapshots/2-TSESTree-Tokens.shot
new file mode 100644
index 000000000000..9227520d1535
--- /dev/null
+++ b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/type-param-one/snapshots/2-TSESTree-Tokens.shot
@@ -0,0 +1,96 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration FunctionDeclaration type-param-one TSESTree - Tokens 1`] = `
+Array [
+  Keyword {
+    type: "Keyword",
+    value: "function",
+
+    range: [0, 8],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 8, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "foo",
+
+    range: [9, 12],
+    loc: {
+      start: { column: 9, line: 1 },
+      end: { column: 12, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "<",
+
+    range: [12, 13],
+    loc: {
+      start: { column: 12, line: 1 },
+      end: { column: 13, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "T",
+
+    range: [13, 14],
+    loc: {
+      start: { column: 13, line: 1 },
+      end: { column: 14, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ">",
+
+    range: [14, 15],
+    loc: {
+      start: { column: 14, line: 1 },
+      end: { column: 15, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "(",
+
+    range: [15, 16],
+    loc: {
+      start: { column: 15, line: 1 },
+      end: { column: 16, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ")",
+
+    range: [16, 17],
+    loc: {
+      start: { column: 16, line: 1 },
+      end: { column: 17, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "{",
+
+    range: [18, 19],
+    loc: {
+      start: { column: 18, line: 1 },
+      end: { column: 19, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "}",
+
+    range: [19, 20],
+    loc: {
+      start: { column: 19, line: 1 },
+      end: { column: 20, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/type-param-one/snapshots/3-Babel-AST.shot b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/type-param-one/snapshots/3-Babel-AST.shot
new file mode 100644
index 000000000000..5083d4d25cb2
--- /dev/null
+++ b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/type-param-one/snapshots/3-Babel-AST.shot
@@ -0,0 +1,70 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration FunctionDeclaration type-param-one Babel - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    FunctionDeclaration {
+      type: "FunctionDeclaration",
+      async: false,
+      body: BlockStatement {
+        type: "BlockStatement",
+        body: Array [],
+
+        range: [18, 20],
+        loc: {
+          start: { column: 18, line: 1 },
+          end: { column: 20, line: 1 },
+        },
+      },
+      expression: false,
+      generator: false,
+      id: Identifier {
+        type: "Identifier",
+        name: "foo",
+
+        range: [9, 12],
+        loc: {
+          start: { column: 9, line: 1 },
+          end: { column: 12, line: 1 },
+        },
+      },
+      params: Array [],
+      typeParameters: TSTypeParameterDeclaration {
+        type: "TSTypeParameterDeclaration",
+        params: Array [
+          TSTypeParameter {
+            type: "TSTypeParameter",
+            name: "T",
+
+            range: [13, 14],
+            loc: {
+              start: { column: 13, line: 1 },
+              end: { column: 14, line: 1 },
+            },
+          },
+        ],
+
+        range: [12, 15],
+        loc: {
+          start: { column: 12, line: 1 },
+          end: { column: 15, line: 1 },
+        },
+      },
+
+      range: [0, 20],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 20, line: 1 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 21],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/type-param-one/snapshots/4-Babel-Tokens.shot b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/type-param-one/snapshots/4-Babel-Tokens.shot
new file mode 100644
index 000000000000..72cd1481fd3f
--- /dev/null
+++ b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/type-param-one/snapshots/4-Babel-Tokens.shot
@@ -0,0 +1,96 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration FunctionDeclaration type-param-one Babel - Tokens 1`] = `
+Array [
+  Keyword {
+    type: "Keyword",
+    value: "function",
+
+    range: [0, 8],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 8, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "foo",
+
+    range: [9, 12],
+    loc: {
+      start: { column: 9, line: 1 },
+      end: { column: 12, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "<",
+
+    range: [12, 13],
+    loc: {
+      start: { column: 12, line: 1 },
+      end: { column: 13, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "T",
+
+    range: [13, 14],
+    loc: {
+      start: { column: 13, line: 1 },
+      end: { column: 14, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ">",
+
+    range: [14, 15],
+    loc: {
+      start: { column: 14, line: 1 },
+      end: { column: 15, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "(",
+
+    range: [15, 16],
+    loc: {
+      start: { column: 15, line: 1 },
+      end: { column: 16, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ")",
+
+    range: [16, 17],
+    loc: {
+      start: { column: 16, line: 1 },
+      end: { column: 17, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "{",
+
+    range: [18, 19],
+    loc: {
+      start: { column: 18, line: 1 },
+      end: { column: 19, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "}",
+
+    range: [19, 20],
+    loc: {
+      start: { column: 19, line: 1 },
+      end: { column: 20, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/type-param-one/snapshots/5-AST-Alignment-AST.shot b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/type-param-one/snapshots/5-AST-Alignment-AST.shot
new file mode 100644
index 000000000000..b997a40aca31
--- /dev/null
+++ b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/type-param-one/snapshots/5-AST-Alignment-AST.shot
@@ -0,0 +1,86 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration FunctionDeclaration type-param-one AST Alignment - AST 1`] = `
+"Snapshot Diff:
+- TSESTree
++ Babel
+
+  Program {
+    type: 'Program',
+    body: Array [
+      FunctionDeclaration {
+        type: 'FunctionDeclaration',
+        async: false,
+        body: BlockStatement {
+          type: 'BlockStatement',
+          body: Array [],
+
+          range: [18, 20],
+          loc: {
+            start: { column: 18, line: 1 },
+            end: { column: 20, line: 1 },
+          },
+        },
+        expression: false,
+        generator: false,
+        id: Identifier {
+          type: 'Identifier',
+          name: 'foo',
+
+          range: [9, 12],
+          loc: {
+            start: { column: 9, line: 1 },
+            end: { column: 12, line: 1 },
+          },
+        },
+        params: Array [],
+        typeParameters: TSTypeParameterDeclaration {
+          type: 'TSTypeParameterDeclaration',
+          params: Array [
+            TSTypeParameter {
+              type: 'TSTypeParameter',
+-             in: false,
+-             name: Identifier {
+-               type: 'Identifier',
+-               name: 'T',
+-
+-               range: [13, 14],
+-               loc: {
+-                 start: { column: 13, line: 1 },
+-                 end: { column: 14, line: 1 },
+-               },
+-             },
+-             out: false,
++             name: 'T',
+
+              range: [13, 14],
+              loc: {
+                start: { column: 13, line: 1 },
+                end: { column: 14, line: 1 },
+              },
+            },
+          ],
+
+          range: [12, 15],
+          loc: {
+            start: { column: 12, line: 1 },
+            end: { column: 15, line: 1 },
+          },
+        },
+
+        range: [0, 20],
+        loc: {
+          start: { column: 0, line: 1 },
+          end: { column: 20, line: 1 },
+        },
+      },
+    ],
+    sourceType: 'script',
+
+    range: [0, 21],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 0, line: 2 },
+    },
+  }"
+`;
diff --git a/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/type-param-one/snapshots/6-AST-Alignment-Tokens.shot b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/type-param-one/snapshots/6-AST-Alignment-Tokens.shot
new file mode 100644
index 000000000000..bf84a177ecc8
--- /dev/null
+++ b/packages/ast-spec/src/declaration/FunctionDeclaration/fixtures/type-param-one/snapshots/6-AST-Alignment-Tokens.shot
@@ -0,0 +1,6 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration FunctionDeclaration type-param-one AST Alignment - Token 1`] = `
+"Snapshot Diff:
+Compared values have no visual difference."
+`;
diff --git a/packages/ast-spec/src/declaration/FunctionDeclaration/spec.ts b/packages/ast-spec/src/declaration/FunctionDeclaration/spec.ts
index 59d7c4ffe39d..4fe3d2dc693e 100644
--- a/packages/ast-spec/src/declaration/FunctionDeclaration/spec.ts
+++ b/packages/ast-spec/src/declaration/FunctionDeclaration/spec.ts
@@ -1,8 +1,25 @@
 import type { AST_NODE_TYPES } from '../../ast-node-types';
-import type { FunctionDeclarationBase } from '../../base/FunctionDeclarationBase';
+import type { FunctionBase } from '../../base/FunctionBase';
+import type { Identifier } from '../../expression/Identifier/spec';
 import type { BlockStatement } from '../../statement/BlockStatement/spec';
 
-export interface FunctionDeclaration extends FunctionDeclarationBase {
+interface FunctionDeclarationBase extends FunctionBase {
   type: AST_NODE_TYPES.FunctionDeclaration;
   body: BlockStatement;
+  // TODO(#5020) - make this always `false` if it is not `declare`d instead of `undefined`
+  declare?: false;
+  expression: false;
 }
+
+export interface FunctionDeclarationWithName extends FunctionDeclarationBase {
+  id: Identifier;
+}
+
+export interface FunctionDeclarationWithOptionalName
+  extends FunctionDeclarationBase {
+  id: Identifier | null;
+}
+
+export type FunctionDeclaration =
+  | FunctionDeclarationWithName
+  | FunctionDeclarationWithOptionalName;
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/_error_/default-non-identifier/fixture.ts b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/_error_/default-non-identifier/fixture.ts
new file mode 100644
index 000000000000..965d8a696533
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/_error_/default-non-identifier/fixture.ts
@@ -0,0 +1 @@
+import 1 from 'mod';
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/_error_/default-non-identifier/snapshots/1-TSESTree-Error.shot b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/_error_/default-non-identifier/snapshots/1-TSESTree-Error.shot
new file mode 100644
index 000000000000..233c225dd505
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/_error_/default-non-identifier/snapshots/1-TSESTree-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ImportDeclaration _error_ default-non-identifier TSESTree - Error 1`] = `[TSError: Declaration or statement expected.]`;
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/_error_/default-non-identifier/snapshots/2-Babel-Error.shot b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/_error_/default-non-identifier/snapshots/2-Babel-Error.shot
new file mode 100644
index 000000000000..438c9cdf7501
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/_error_/default-non-identifier/snapshots/2-Babel-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ImportDeclaration _error_ default-non-identifier Babel - Error 1`] = `[SyntaxError: Unexpected token, expected "{" (1:7)]`;
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/_error_/default-non-identifier/snapshots/3-Alignment-Error.shot b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/_error_/default-non-identifier/snapshots/3-Alignment-Error.shot
new file mode 100644
index 000000000000..2e0bcbec5a5e
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/_error_/default-non-identifier/snapshots/3-Alignment-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ImportDeclaration _error_ default-non-identifier Error Alignment 1`] = `"Both errored"`;
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/_error_/named-and-namespace/fixture.ts b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/_error_/named-and-namespace/fixture.ts
new file mode 100644
index 000000000000..f3cb6e658e22
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/_error_/named-and-namespace/fixture.ts
@@ -0,0 +1 @@
+import { b }, * as a from 'a';
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/_error_/named-and-namespace/snapshots/1-TSESTree-Error.shot b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/_error_/named-and-namespace/snapshots/1-TSESTree-Error.shot
new file mode 100644
index 000000000000..d94d399517ff
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/_error_/named-and-namespace/snapshots/1-TSESTree-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ImportDeclaration _error_ named-and-namespace TSESTree - Error 1`] = `[TSError: 'from' expected.]`;
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/_error_/named-and-namespace/snapshots/2-Babel-Error.shot b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/_error_/named-and-namespace/snapshots/2-Babel-Error.shot
new file mode 100644
index 000000000000..9cf4c4b719a9
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/_error_/named-and-namespace/snapshots/2-Babel-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ImportDeclaration _error_ named-and-namespace Babel - Error 1`] = `[SyntaxError: Unexpected token, expected "from" (1:12)]`;
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/_error_/named-and-namespace/snapshots/3-Alignment-Error.shot b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/_error_/named-and-namespace/snapshots/3-Alignment-Error.shot
new file mode 100644
index 000000000000..89fae3fa27c3
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/_error_/named-and-namespace/snapshots/3-Alignment-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ImportDeclaration _error_ named-and-namespace Error Alignment 1`] = `"Both errored"`;
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/_error_/named-non-identifier/fixture.ts b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/_error_/named-non-identifier/fixture.ts
new file mode 100644
index 000000000000..6a7fb92600de
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/_error_/named-non-identifier/fixture.ts
@@ -0,0 +1 @@
+import { 1 } from 'mod';
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/_error_/named-non-identifier/snapshots/1-TSESTree-Error.shot b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/_error_/named-non-identifier/snapshots/1-TSESTree-Error.shot
new file mode 100644
index 000000000000..2ca1651099be
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/_error_/named-non-identifier/snapshots/1-TSESTree-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ImportDeclaration _error_ named-non-identifier TSESTree - Error 1`] = `[TSError: Identifier expected.]`;
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/_error_/named-non-identifier/snapshots/2-Babel-Error.shot b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/_error_/named-non-identifier/snapshots/2-Babel-Error.shot
new file mode 100644
index 000000000000..970528e3253d
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/_error_/named-non-identifier/snapshots/2-Babel-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ImportDeclaration _error_ named-non-identifier Babel - Error 1`] = `[SyntaxError: Unexpected token (1:9)]`;
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/_error_/named-non-identifier/snapshots/3-Alignment-Error.shot b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/_error_/named-non-identifier/snapshots/3-Alignment-Error.shot
new file mode 100644
index 000000000000..fefbeef9c524
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/_error_/named-non-identifier/snapshots/3-Alignment-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ImportDeclaration _error_ named-non-identifier Error Alignment 1`] = `"Both errored"`;
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/_error_/namespace-and-default/fixture.ts b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/_error_/namespace-and-default/fixture.ts
new file mode 100644
index 000000000000..9f7ee22b7ddf
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/_error_/namespace-and-default/fixture.ts
@@ -0,0 +1 @@
+import * as b, a from 'mod';
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/_error_/namespace-and-default/snapshots/1-TSESTree-Error.shot b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/_error_/namespace-and-default/snapshots/1-TSESTree-Error.shot
new file mode 100644
index 000000000000..9d2be22fe16f
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/_error_/namespace-and-default/snapshots/1-TSESTree-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ImportDeclaration _error_ namespace-and-default TSESTree - Error 1`] = `[TSError: 'from' expected.]`;
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/_error_/namespace-and-default/snapshots/2-Babel-Error.shot b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/_error_/namespace-and-default/snapshots/2-Babel-Error.shot
new file mode 100644
index 000000000000..294d069aacc6
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/_error_/namespace-and-default/snapshots/2-Babel-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ImportDeclaration _error_ namespace-and-default Babel - Error 1`] = `[SyntaxError: Unexpected token, expected "from" (1:13)]`;
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/_error_/namespace-and-default/snapshots/3-Alignment-Error.shot b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/_error_/namespace-and-default/snapshots/3-Alignment-Error.shot
new file mode 100644
index 000000000000..6e491db0e63b
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/_error_/namespace-and-default/snapshots/3-Alignment-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ImportDeclaration _error_ namespace-and-default Error Alignment 1`] = `"Both errored"`;
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/_error_/namespace-and-named/fixture.ts b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/_error_/namespace-and-named/fixture.ts
new file mode 100644
index 000000000000..52bcac2fdbf7
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/_error_/namespace-and-named/fixture.ts
@@ -0,0 +1 @@
+import * as a, { b } from 'a';
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/_error_/namespace-and-named/snapshots/1-TSESTree-Error.shot b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/_error_/namespace-and-named/snapshots/1-TSESTree-Error.shot
new file mode 100644
index 000000000000..a2271606e4be
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/_error_/namespace-and-named/snapshots/1-TSESTree-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ImportDeclaration _error_ namespace-and-named TSESTree - Error 1`] = `[TSError: 'from' expected.]`;
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/_error_/namespace-and-named/snapshots/2-Babel-Error.shot b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/_error_/namespace-and-named/snapshots/2-Babel-Error.shot
new file mode 100644
index 000000000000..605940a84336
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/_error_/namespace-and-named/snapshots/2-Babel-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ImportDeclaration _error_ namespace-and-named Babel - Error 1`] = `[SyntaxError: Unexpected token, expected "from" (1:13)]`;
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/_error_/namespace-and-named/snapshots/3-Alignment-Error.shot b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/_error_/namespace-and-named/snapshots/3-Alignment-Error.shot
new file mode 100644
index 000000000000..f1e891dbecaf
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/_error_/namespace-and-named/snapshots/3-Alignment-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ImportDeclaration _error_ namespace-and-named Error Alignment 1`] = `"Both errored"`;
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/_error_/namespace-and-namespace/fixture.ts b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/_error_/namespace-and-namespace/fixture.ts
new file mode 100644
index 000000000000..6d678fc59835
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/_error_/namespace-and-namespace/fixture.ts
@@ -0,0 +1 @@
+import * as a, * as b from 'a';
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/_error_/namespace-and-namespace/snapshots/1-TSESTree-Error.shot b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/_error_/namespace-and-namespace/snapshots/1-TSESTree-Error.shot
new file mode 100644
index 000000000000..0a5d4ab3922f
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/_error_/namespace-and-namespace/snapshots/1-TSESTree-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ImportDeclaration _error_ namespace-and-namespace TSESTree - Error 1`] = `[TSError: 'from' expected.]`;
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/_error_/namespace-and-namespace/snapshots/2-Babel-Error.shot b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/_error_/namespace-and-namespace/snapshots/2-Babel-Error.shot
new file mode 100644
index 000000000000..8efbfcaf5191
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/_error_/namespace-and-namespace/snapshots/2-Babel-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ImportDeclaration _error_ namespace-and-namespace Babel - Error 1`] = `[SyntaxError: Unexpected token, expected "from" (1:13)]`;
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/_error_/namespace-and-namespace/snapshots/3-Alignment-Error.shot b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/_error_/namespace-and-namespace/snapshots/3-Alignment-Error.shot
new file mode 100644
index 000000000000..e3c8c7a6288d
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/_error_/namespace-and-namespace/snapshots/3-Alignment-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ImportDeclaration _error_ namespace-and-namespace Error Alignment 1`] = `"Both errored"`;
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/_error_/namespace-non-identifier/fixture.ts b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/_error_/namespace-non-identifier/fixture.ts
new file mode 100644
index 000000000000..539e09df8d0e
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/_error_/namespace-non-identifier/fixture.ts
@@ -0,0 +1 @@
+import * as 1 from 'mod';
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/_error_/namespace-non-identifier/snapshots/1-TSESTree-Error.shot b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/_error_/namespace-non-identifier/snapshots/1-TSESTree-Error.shot
new file mode 100644
index 000000000000..fa9ec459a928
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/_error_/namespace-non-identifier/snapshots/1-TSESTree-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ImportDeclaration _error_ namespace-non-identifier TSESTree - Error 1`] = `[TSError: Identifier expected.]`;
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/_error_/namespace-non-identifier/snapshots/2-Babel-Error.shot b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/_error_/namespace-non-identifier/snapshots/2-Babel-Error.shot
new file mode 100644
index 000000000000..a511cc6c94d3
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/_error_/namespace-non-identifier/snapshots/2-Babel-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ImportDeclaration _error_ namespace-non-identifier Babel - Error 1`] = `[SyntaxError: Unexpected token (1:12)]`;
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/_error_/namespace-non-identifier/snapshots/3-Alignment-Error.shot b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/_error_/namespace-non-identifier/snapshots/3-Alignment-Error.shot
new file mode 100644
index 000000000000..f0d97ae32bc8
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/_error_/namespace-non-identifier/snapshots/3-Alignment-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ImportDeclaration _error_ namespace-non-identifier Error Alignment 1`] = `"Both errored"`;
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/_error_/non-string-source/fixture.ts b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/_error_/non-string-source/fixture.ts
new file mode 100644
index 000000000000..a4a63604c811
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/_error_/non-string-source/fixture.ts
@@ -0,0 +1 @@
+import * as x from module;
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/_error_/non-string-source/snapshots/1-TSESTree-Error.shot b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/_error_/non-string-source/snapshots/1-TSESTree-Error.shot
new file mode 100644
index 000000000000..4cfff84fd98c
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/_error_/non-string-source/snapshots/1-TSESTree-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ImportDeclaration _error_ non-string-source TSESTree - Error 1`] = `[TSError: Module specifier must be a string literal.]`;
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/_error_/non-string-source/snapshots/2-Babel-Error.shot b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/_error_/non-string-source/snapshots/2-Babel-Error.shot
new file mode 100644
index 000000000000..49abb8366621
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/_error_/non-string-source/snapshots/2-Babel-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ImportDeclaration _error_ non-string-source Babel - Error 1`] = `[SyntaxError: Unexpected token (1:19)]`;
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/_error_/non-string-source/snapshots/3-Alignment-Error.shot b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/_error_/non-string-source/snapshots/3-Alignment-Error.shot
new file mode 100644
index 000000000000..0d5964ffc24c
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/_error_/non-string-source/snapshots/3-Alignment-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ImportDeclaration _error_ non-string-source Error Alignment 1`] = `"Both errored"`;
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/assertion/fixture.ts b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/assertion/fixture.ts
new file mode 100644
index 000000000000..3bd366a8d054
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/assertion/fixture.ts
@@ -0,0 +1 @@
+import * as a from 'mod' assert { type: 'json' };
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/assertion/snapshots/1-TSESTree-AST.shot b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/assertion/snapshots/1-TSESTree-AST.shot
new file mode 100644
index 000000000000..877884e2c9ad
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/assertion/snapshots/1-TSESTree-AST.shot
@@ -0,0 +1,90 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ImportDeclaration assertion TSESTree - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    ImportDeclaration {
+      type: "ImportDeclaration",
+      assertions: Array [
+        ImportAttribute {
+          type: "ImportAttribute",
+          key: Identifier {
+            type: "Identifier",
+            name: "type",
+
+            range: [34, 38],
+            loc: {
+              start: { column: 34, line: 1 },
+              end: { column: 38, line: 1 },
+            },
+          },
+          value: Literal {
+            type: "Literal",
+            raw: "'json'",
+            value: "json",
+
+            range: [40, 46],
+            loc: {
+              start: { column: 40, line: 1 },
+              end: { column: 46, line: 1 },
+            },
+          },
+
+          range: [34, 46],
+          loc: {
+            start: { column: 34, line: 1 },
+            end: { column: 46, line: 1 },
+          },
+        },
+      ],
+      importKind: "value",
+      source: Literal {
+        type: "Literal",
+        raw: "'mod'",
+        value: "mod",
+
+        range: [19, 24],
+        loc: {
+          start: { column: 19, line: 1 },
+          end: { column: 24, line: 1 },
+        },
+      },
+      specifiers: Array [
+        ImportNamespaceSpecifier {
+          type: "ImportNamespaceSpecifier",
+          local: Identifier {
+            type: "Identifier",
+            name: "a",
+
+            range: [12, 13],
+            loc: {
+              start: { column: 12, line: 1 },
+              end: { column: 13, line: 1 },
+            },
+          },
+
+          range: [7, 13],
+          loc: {
+            start: { column: 7, line: 1 },
+            end: { column: 13, line: 1 },
+          },
+        },
+      ],
+
+      range: [0, 49],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 49, line: 1 },
+      },
+    },
+  ],
+  sourceType: "module",
+
+  range: [0, 50],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/assertion/snapshots/2-TSESTree-Tokens.shot b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/assertion/snapshots/2-TSESTree-Tokens.shot
new file mode 100644
index 000000000000..3b0706c7d31f
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/assertion/snapshots/2-TSESTree-Tokens.shot
@@ -0,0 +1,136 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ImportDeclaration assertion TSESTree - Tokens 1`] = `
+Array [
+  Keyword {
+    type: "Keyword",
+    value: "import",
+
+    range: [0, 6],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 6, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "*",
+
+    range: [7, 8],
+    loc: {
+      start: { column: 7, line: 1 },
+      end: { column: 8, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "as",
+
+    range: [9, 11],
+    loc: {
+      start: { column: 9, line: 1 },
+      end: { column: 11, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "a",
+
+    range: [12, 13],
+    loc: {
+      start: { column: 12, line: 1 },
+      end: { column: 13, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "from",
+
+    range: [14, 18],
+    loc: {
+      start: { column: 14, line: 1 },
+      end: { column: 18, line: 1 },
+    },
+  },
+  String {
+    type: "String",
+    value: "'mod'",
+
+    range: [19, 24],
+    loc: {
+      start: { column: 19, line: 1 },
+      end: { column: 24, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "assert",
+
+    range: [25, 31],
+    loc: {
+      start: { column: 25, line: 1 },
+      end: { column: 31, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "{",
+
+    range: [32, 33],
+    loc: {
+      start: { column: 32, line: 1 },
+      end: { column: 33, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "type",
+
+    range: [34, 38],
+    loc: {
+      start: { column: 34, line: 1 },
+      end: { column: 38, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ":",
+
+    range: [38, 39],
+    loc: {
+      start: { column: 38, line: 1 },
+      end: { column: 39, line: 1 },
+    },
+  },
+  String {
+    type: "String",
+    value: "'json'",
+
+    range: [40, 46],
+    loc: {
+      start: { column: 40, line: 1 },
+      end: { column: 46, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "}",
+
+    range: [47, 48],
+    loc: {
+      start: { column: 47, line: 1 },
+      end: { column: 48, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ";",
+
+    range: [48, 49],
+    loc: {
+      start: { column: 48, line: 1 },
+      end: { column: 49, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/assertion/snapshots/3-Babel-AST.shot b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/assertion/snapshots/3-Babel-AST.shot
new file mode 100644
index 000000000000..54c2381228b0
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/assertion/snapshots/3-Babel-AST.shot
@@ -0,0 +1,90 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ImportDeclaration assertion Babel - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    ImportDeclaration {
+      type: "ImportDeclaration",
+      assertions: Array [
+        ImportAttribute {
+          type: "ImportAttribute",
+          key: Identifier {
+            type: "Identifier",
+            name: "type",
+
+            range: [34, 38],
+            loc: {
+              start: { column: 34, line: 1 },
+              end: { column: 38, line: 1 },
+            },
+          },
+          value: Literal {
+            type: "Literal",
+            raw: "'json'",
+            value: "json",
+
+            range: [40, 46],
+            loc: {
+              start: { column: 40, line: 1 },
+              end: { column: 46, line: 1 },
+            },
+          },
+
+          range: [34, 46],
+          loc: {
+            start: { column: 34, line: 1 },
+            end: { column: 46, line: 1 },
+          },
+        },
+      ],
+      importKind: "value",
+      source: Literal {
+        type: "Literal",
+        raw: "'mod'",
+        value: "mod",
+
+        range: [19, 24],
+        loc: {
+          start: { column: 19, line: 1 },
+          end: { column: 24, line: 1 },
+        },
+      },
+      specifiers: Array [
+        ImportNamespaceSpecifier {
+          type: "ImportNamespaceSpecifier",
+          local: Identifier {
+            type: "Identifier",
+            name: "a",
+
+            range: [12, 13],
+            loc: {
+              start: { column: 12, line: 1 },
+              end: { column: 13, line: 1 },
+            },
+          },
+
+          range: [7, 13],
+          loc: {
+            start: { column: 7, line: 1 },
+            end: { column: 13, line: 1 },
+          },
+        },
+      ],
+
+      range: [0, 49],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 49, line: 1 },
+      },
+    },
+  ],
+  sourceType: "module",
+
+  range: [0, 50],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/assertion/snapshots/4-Babel-Tokens.shot b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/assertion/snapshots/4-Babel-Tokens.shot
new file mode 100644
index 000000000000..30c2bd49245d
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/assertion/snapshots/4-Babel-Tokens.shot
@@ -0,0 +1,136 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ImportDeclaration assertion Babel - Tokens 1`] = `
+Array [
+  Keyword {
+    type: "Keyword",
+    value: "import",
+
+    range: [0, 6],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 6, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "*",
+
+    range: [7, 8],
+    loc: {
+      start: { column: 7, line: 1 },
+      end: { column: 8, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "as",
+
+    range: [9, 11],
+    loc: {
+      start: { column: 9, line: 1 },
+      end: { column: 11, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "a",
+
+    range: [12, 13],
+    loc: {
+      start: { column: 12, line: 1 },
+      end: { column: 13, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "from",
+
+    range: [14, 18],
+    loc: {
+      start: { column: 14, line: 1 },
+      end: { column: 18, line: 1 },
+    },
+  },
+  String {
+    type: "String",
+    value: "'mod'",
+
+    range: [19, 24],
+    loc: {
+      start: { column: 19, line: 1 },
+      end: { column: 24, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "assert",
+
+    range: [25, 31],
+    loc: {
+      start: { column: 25, line: 1 },
+      end: { column: 31, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "{",
+
+    range: [32, 33],
+    loc: {
+      start: { column: 32, line: 1 },
+      end: { column: 33, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "type",
+
+    range: [34, 38],
+    loc: {
+      start: { column: 34, line: 1 },
+      end: { column: 38, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ":",
+
+    range: [38, 39],
+    loc: {
+      start: { column: 38, line: 1 },
+      end: { column: 39, line: 1 },
+    },
+  },
+  String {
+    type: "String",
+    value: "'json'",
+
+    range: [40, 46],
+    loc: {
+      start: { column: 40, line: 1 },
+      end: { column: 46, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "}",
+
+    range: [47, 48],
+    loc: {
+      start: { column: 47, line: 1 },
+      end: { column: 48, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ";",
+
+    range: [48, 49],
+    loc: {
+      start: { column: 48, line: 1 },
+      end: { column: 49, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/assertion/snapshots/5-AST-Alignment-AST.shot b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/assertion/snapshots/5-AST-Alignment-AST.shot
new file mode 100644
index 000000000000..c7b85e439dad
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/assertion/snapshots/5-AST-Alignment-AST.shot
@@ -0,0 +1,6 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ImportDeclaration assertion AST Alignment - AST 1`] = `
+"Snapshot Diff:
+Compared values have no visual difference."
+`;
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/assertion/snapshots/6-AST-Alignment-Tokens.shot b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/assertion/snapshots/6-AST-Alignment-Tokens.shot
new file mode 100644
index 000000000000..3189b2704ef9
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/assertion/snapshots/6-AST-Alignment-Tokens.shot
@@ -0,0 +1,6 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ImportDeclaration assertion AST Alignment - Token 1`] = `
+"Snapshot Diff:
+Compared values have no visual difference."
+`;
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default-and-named-many/fixture.ts b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default-and-named-many/fixture.ts
new file mode 100644
index 000000000000..ac5f18056a31
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default-and-named-many/fixture.ts
@@ -0,0 +1 @@
+import a, { b, c, d } from 'mod';
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default-and-named-many/snapshots/1-TSESTree-AST.shot b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default-and-named-many/snapshots/1-TSESTree-AST.shot
new file mode 100644
index 000000000000..3b5e6f5d956a
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default-and-named-many/snapshots/1-TSESTree-AST.shot
@@ -0,0 +1,149 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ImportDeclaration default-and-named-many TSESTree - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    ImportDeclaration {
+      type: "ImportDeclaration",
+      assertions: Array [],
+      importKind: "value",
+      source: Literal {
+        type: "Literal",
+        raw: "'mod'",
+        value: "mod",
+
+        range: [27, 32],
+        loc: {
+          start: { column: 27, line: 1 },
+          end: { column: 32, line: 1 },
+        },
+      },
+      specifiers: Array [
+        ImportDefaultSpecifier {
+          type: "ImportDefaultSpecifier",
+          local: Identifier {
+            type: "Identifier",
+            name: "a",
+
+            range: [7, 8],
+            loc: {
+              start: { column: 7, line: 1 },
+              end: { column: 8, line: 1 },
+            },
+          },
+
+          range: [7, 8],
+          loc: {
+            start: { column: 7, line: 1 },
+            end: { column: 8, line: 1 },
+          },
+        },
+        ImportSpecifier {
+          type: "ImportSpecifier",
+          imported: Identifier {
+            type: "Identifier",
+            name: "b",
+
+            range: [12, 13],
+            loc: {
+              start: { column: 12, line: 1 },
+              end: { column: 13, line: 1 },
+            },
+          },
+          importKind: "value",
+          local: Identifier {
+            type: "Identifier",
+            name: "b",
+
+            range: [12, 13],
+            loc: {
+              start: { column: 12, line: 1 },
+              end: { column: 13, line: 1 },
+            },
+          },
+
+          range: [12, 13],
+          loc: {
+            start: { column: 12, line: 1 },
+            end: { column: 13, line: 1 },
+          },
+        },
+        ImportSpecifier {
+          type: "ImportSpecifier",
+          imported: Identifier {
+            type: "Identifier",
+            name: "c",
+
+            range: [15, 16],
+            loc: {
+              start: { column: 15, line: 1 },
+              end: { column: 16, line: 1 },
+            },
+          },
+          importKind: "value",
+          local: Identifier {
+            type: "Identifier",
+            name: "c",
+
+            range: [15, 16],
+            loc: {
+              start: { column: 15, line: 1 },
+              end: { column: 16, line: 1 },
+            },
+          },
+
+          range: [15, 16],
+          loc: {
+            start: { column: 15, line: 1 },
+            end: { column: 16, line: 1 },
+          },
+        },
+        ImportSpecifier {
+          type: "ImportSpecifier",
+          imported: Identifier {
+            type: "Identifier",
+            name: "d",
+
+            range: [18, 19],
+            loc: {
+              start: { column: 18, line: 1 },
+              end: { column: 19, line: 1 },
+            },
+          },
+          importKind: "value",
+          local: Identifier {
+            type: "Identifier",
+            name: "d",
+
+            range: [18, 19],
+            loc: {
+              start: { column: 18, line: 1 },
+              end: { column: 19, line: 1 },
+            },
+          },
+
+          range: [18, 19],
+          loc: {
+            start: { column: 18, line: 1 },
+            end: { column: 19, line: 1 },
+          },
+        },
+      ],
+
+      range: [0, 33],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 33, line: 1 },
+      },
+    },
+  ],
+  sourceType: "module",
+
+  range: [0, 34],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default-and-named-many/snapshots/2-TSESTree-Tokens.shot b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default-and-named-many/snapshots/2-TSESTree-Tokens.shot
new file mode 100644
index 000000000000..1d4c57f89eb5
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default-and-named-many/snapshots/2-TSESTree-Tokens.shot
@@ -0,0 +1,136 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ImportDeclaration default-and-named-many TSESTree - Tokens 1`] = `
+Array [
+  Keyword {
+    type: "Keyword",
+    value: "import",
+
+    range: [0, 6],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 6, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "a",
+
+    range: [7, 8],
+    loc: {
+      start: { column: 7, line: 1 },
+      end: { column: 8, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ",",
+
+    range: [8, 9],
+    loc: {
+      start: { column: 8, line: 1 },
+      end: { column: 9, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "{",
+
+    range: [10, 11],
+    loc: {
+      start: { column: 10, line: 1 },
+      end: { column: 11, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "b",
+
+    range: [12, 13],
+    loc: {
+      start: { column: 12, line: 1 },
+      end: { column: 13, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ",",
+
+    range: [13, 14],
+    loc: {
+      start: { column: 13, line: 1 },
+      end: { column: 14, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "c",
+
+    range: [15, 16],
+    loc: {
+      start: { column: 15, line: 1 },
+      end: { column: 16, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ",",
+
+    range: [16, 17],
+    loc: {
+      start: { column: 16, line: 1 },
+      end: { column: 17, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "d",
+
+    range: [18, 19],
+    loc: {
+      start: { column: 18, line: 1 },
+      end: { column: 19, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "}",
+
+    range: [20, 21],
+    loc: {
+      start: { column: 20, line: 1 },
+      end: { column: 21, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "from",
+
+    range: [22, 26],
+    loc: {
+      start: { column: 22, line: 1 },
+      end: { column: 26, line: 1 },
+    },
+  },
+  String {
+    type: "String",
+    value: "'mod'",
+
+    range: [27, 32],
+    loc: {
+      start: { column: 27, line: 1 },
+      end: { column: 32, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ";",
+
+    range: [32, 33],
+    loc: {
+      start: { column: 32, line: 1 },
+      end: { column: 33, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default-and-named-many/snapshots/3-Babel-AST.shot b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default-and-named-many/snapshots/3-Babel-AST.shot
new file mode 100644
index 000000000000..d1207f8c6cc5
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default-and-named-many/snapshots/3-Babel-AST.shot
@@ -0,0 +1,149 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ImportDeclaration default-and-named-many Babel - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    ImportDeclaration {
+      type: "ImportDeclaration",
+      assertions: Array [],
+      importKind: "value",
+      source: Literal {
+        type: "Literal",
+        raw: "'mod'",
+        value: "mod",
+
+        range: [27, 32],
+        loc: {
+          start: { column: 27, line: 1 },
+          end: { column: 32, line: 1 },
+        },
+      },
+      specifiers: Array [
+        ImportDefaultSpecifier {
+          type: "ImportDefaultSpecifier",
+          local: Identifier {
+            type: "Identifier",
+            name: "a",
+
+            range: [7, 8],
+            loc: {
+              start: { column: 7, line: 1 },
+              end: { column: 8, line: 1 },
+            },
+          },
+
+          range: [7, 8],
+          loc: {
+            start: { column: 7, line: 1 },
+            end: { column: 8, line: 1 },
+          },
+        },
+        ImportSpecifier {
+          type: "ImportSpecifier",
+          imported: Identifier {
+            type: "Identifier",
+            name: "b",
+
+            range: [12, 13],
+            loc: {
+              start: { column: 12, line: 1 },
+              end: { column: 13, line: 1 },
+            },
+          },
+          importKind: "value",
+          local: Identifier {
+            type: "Identifier",
+            name: "b",
+
+            range: [12, 13],
+            loc: {
+              start: { column: 12, line: 1 },
+              end: { column: 13, line: 1 },
+            },
+          },
+
+          range: [12, 13],
+          loc: {
+            start: { column: 12, line: 1 },
+            end: { column: 13, line: 1 },
+          },
+        },
+        ImportSpecifier {
+          type: "ImportSpecifier",
+          imported: Identifier {
+            type: "Identifier",
+            name: "c",
+
+            range: [15, 16],
+            loc: {
+              start: { column: 15, line: 1 },
+              end: { column: 16, line: 1 },
+            },
+          },
+          importKind: "value",
+          local: Identifier {
+            type: "Identifier",
+            name: "c",
+
+            range: [15, 16],
+            loc: {
+              start: { column: 15, line: 1 },
+              end: { column: 16, line: 1 },
+            },
+          },
+
+          range: [15, 16],
+          loc: {
+            start: { column: 15, line: 1 },
+            end: { column: 16, line: 1 },
+          },
+        },
+        ImportSpecifier {
+          type: "ImportSpecifier",
+          imported: Identifier {
+            type: "Identifier",
+            name: "d",
+
+            range: [18, 19],
+            loc: {
+              start: { column: 18, line: 1 },
+              end: { column: 19, line: 1 },
+            },
+          },
+          importKind: "value",
+          local: Identifier {
+            type: "Identifier",
+            name: "d",
+
+            range: [18, 19],
+            loc: {
+              start: { column: 18, line: 1 },
+              end: { column: 19, line: 1 },
+            },
+          },
+
+          range: [18, 19],
+          loc: {
+            start: { column: 18, line: 1 },
+            end: { column: 19, line: 1 },
+          },
+        },
+      ],
+
+      range: [0, 33],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 33, line: 1 },
+      },
+    },
+  ],
+  sourceType: "module",
+
+  range: [0, 34],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default-and-named-many/snapshots/4-Babel-Tokens.shot b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default-and-named-many/snapshots/4-Babel-Tokens.shot
new file mode 100644
index 000000000000..3cfb21679c8e
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default-and-named-many/snapshots/4-Babel-Tokens.shot
@@ -0,0 +1,136 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ImportDeclaration default-and-named-many Babel - Tokens 1`] = `
+Array [
+  Keyword {
+    type: "Keyword",
+    value: "import",
+
+    range: [0, 6],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 6, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "a",
+
+    range: [7, 8],
+    loc: {
+      start: { column: 7, line: 1 },
+      end: { column: 8, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ",",
+
+    range: [8, 9],
+    loc: {
+      start: { column: 8, line: 1 },
+      end: { column: 9, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "{",
+
+    range: [10, 11],
+    loc: {
+      start: { column: 10, line: 1 },
+      end: { column: 11, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "b",
+
+    range: [12, 13],
+    loc: {
+      start: { column: 12, line: 1 },
+      end: { column: 13, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ",",
+
+    range: [13, 14],
+    loc: {
+      start: { column: 13, line: 1 },
+      end: { column: 14, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "c",
+
+    range: [15, 16],
+    loc: {
+      start: { column: 15, line: 1 },
+      end: { column: 16, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ",",
+
+    range: [16, 17],
+    loc: {
+      start: { column: 16, line: 1 },
+      end: { column: 17, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "d",
+
+    range: [18, 19],
+    loc: {
+      start: { column: 18, line: 1 },
+      end: { column: 19, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "}",
+
+    range: [20, 21],
+    loc: {
+      start: { column: 20, line: 1 },
+      end: { column: 21, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "from",
+
+    range: [22, 26],
+    loc: {
+      start: { column: 22, line: 1 },
+      end: { column: 26, line: 1 },
+    },
+  },
+  String {
+    type: "String",
+    value: "'mod'",
+
+    range: [27, 32],
+    loc: {
+      start: { column: 27, line: 1 },
+      end: { column: 32, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ";",
+
+    range: [32, 33],
+    loc: {
+      start: { column: 32, line: 1 },
+      end: { column: 33, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default-and-named-many/snapshots/5-AST-Alignment-AST.shot b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default-and-named-many/snapshots/5-AST-Alignment-AST.shot
new file mode 100644
index 000000000000..5a7d0eb9f83d
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default-and-named-many/snapshots/5-AST-Alignment-AST.shot
@@ -0,0 +1,6 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ImportDeclaration default-and-named-many AST Alignment - AST 1`] = `
+"Snapshot Diff:
+Compared values have no visual difference."
+`;
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default-and-named-many/snapshots/6-AST-Alignment-Tokens.shot b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default-and-named-many/snapshots/6-AST-Alignment-Tokens.shot
new file mode 100644
index 000000000000..00895e193743
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default-and-named-many/snapshots/6-AST-Alignment-Tokens.shot
@@ -0,0 +1,6 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ImportDeclaration default-and-named-many AST Alignment - Token 1`] = `
+"Snapshot Diff:
+Compared values have no visual difference."
+`;
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default-and-named-none/fixture.ts b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default-and-named-none/fixture.ts
new file mode 100644
index 000000000000..d808a750ce81
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default-and-named-none/fixture.ts
@@ -0,0 +1,2 @@
+// prettier-ignore
+import a, {} from 'mod';
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default-and-named-none/snapshots/1-TSESTree-AST.shot b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default-and-named-none/snapshots/1-TSESTree-AST.shot
new file mode 100644
index 000000000000..0e94a0b6bb97
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default-and-named-none/snapshots/1-TSESTree-AST.shot
@@ -0,0 +1,59 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ImportDeclaration default-and-named-none TSESTree - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    ImportDeclaration {
+      type: "ImportDeclaration",
+      assertions: Array [],
+      importKind: "value",
+      source: Literal {
+        type: "Literal",
+        raw: "'mod'",
+        value: "mod",
+
+        range: [37, 42],
+        loc: {
+          start: { column: 18, line: 2 },
+          end: { column: 23, line: 2 },
+        },
+      },
+      specifiers: Array [
+        ImportDefaultSpecifier {
+          type: "ImportDefaultSpecifier",
+          local: Identifier {
+            type: "Identifier",
+            name: "a",
+
+            range: [26, 27],
+            loc: {
+              start: { column: 7, line: 2 },
+              end: { column: 8, line: 2 },
+            },
+          },
+
+          range: [26, 27],
+          loc: {
+            start: { column: 7, line: 2 },
+            end: { column: 8, line: 2 },
+          },
+        },
+      ],
+
+      range: [19, 43],
+      loc: {
+        start: { column: 0, line: 2 },
+        end: { column: 24, line: 2 },
+      },
+    },
+  ],
+  sourceType: "module",
+
+  range: [19, 44],
+  loc: {
+    start: { column: 0, line: 2 },
+    end: { column: 0, line: 3 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default-and-named-none/snapshots/2-TSESTree-Tokens.shot b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default-and-named-none/snapshots/2-TSESTree-Tokens.shot
new file mode 100644
index 000000000000..99bb6d113e54
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default-and-named-none/snapshots/2-TSESTree-Tokens.shot
@@ -0,0 +1,86 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ImportDeclaration default-and-named-none TSESTree - Tokens 1`] = `
+Array [
+  Keyword {
+    type: "Keyword",
+    value: "import",
+
+    range: [19, 25],
+    loc: {
+      start: { column: 0, line: 2 },
+      end: { column: 6, line: 2 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "a",
+
+    range: [26, 27],
+    loc: {
+      start: { column: 7, line: 2 },
+      end: { column: 8, line: 2 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ",",
+
+    range: [27, 28],
+    loc: {
+      start: { column: 8, line: 2 },
+      end: { column: 9, line: 2 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "{",
+
+    range: [29, 30],
+    loc: {
+      start: { column: 10, line: 2 },
+      end: { column: 11, line: 2 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "}",
+
+    range: [30, 31],
+    loc: {
+      start: { column: 11, line: 2 },
+      end: { column: 12, line: 2 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "from",
+
+    range: [32, 36],
+    loc: {
+      start: { column: 13, line: 2 },
+      end: { column: 17, line: 2 },
+    },
+  },
+  String {
+    type: "String",
+    value: "'mod'",
+
+    range: [37, 42],
+    loc: {
+      start: { column: 18, line: 2 },
+      end: { column: 23, line: 2 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ";",
+
+    range: [42, 43],
+    loc: {
+      start: { column: 23, line: 2 },
+      end: { column: 24, line: 2 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default-and-named-none/snapshots/3-Babel-AST.shot b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default-and-named-none/snapshots/3-Babel-AST.shot
new file mode 100644
index 000000000000..ee34379e43eb
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default-and-named-none/snapshots/3-Babel-AST.shot
@@ -0,0 +1,59 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ImportDeclaration default-and-named-none Babel - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    ImportDeclaration {
+      type: "ImportDeclaration",
+      assertions: Array [],
+      importKind: "value",
+      source: Literal {
+        type: "Literal",
+        raw: "'mod'",
+        value: "mod",
+
+        range: [37, 42],
+        loc: {
+          start: { column: 18, line: 2 },
+          end: { column: 23, line: 2 },
+        },
+      },
+      specifiers: Array [
+        ImportDefaultSpecifier {
+          type: "ImportDefaultSpecifier",
+          local: Identifier {
+            type: "Identifier",
+            name: "a",
+
+            range: [26, 27],
+            loc: {
+              start: { column: 7, line: 2 },
+              end: { column: 8, line: 2 },
+            },
+          },
+
+          range: [26, 27],
+          loc: {
+            start: { column: 7, line: 2 },
+            end: { column: 8, line: 2 },
+          },
+        },
+      ],
+
+      range: [19, 43],
+      loc: {
+        start: { column: 0, line: 2 },
+        end: { column: 24, line: 2 },
+      },
+    },
+  ],
+  sourceType: "module",
+
+  range: [19, 44],
+  loc: {
+    start: { column: 0, line: 2 },
+    end: { column: 0, line: 3 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default-and-named-none/snapshots/4-Babel-Tokens.shot b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default-and-named-none/snapshots/4-Babel-Tokens.shot
new file mode 100644
index 000000000000..56ab10c4f1c8
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default-and-named-none/snapshots/4-Babel-Tokens.shot
@@ -0,0 +1,86 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ImportDeclaration default-and-named-none Babel - Tokens 1`] = `
+Array [
+  Keyword {
+    type: "Keyword",
+    value: "import",
+
+    range: [19, 25],
+    loc: {
+      start: { column: 0, line: 2 },
+      end: { column: 6, line: 2 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "a",
+
+    range: [26, 27],
+    loc: {
+      start: { column: 7, line: 2 },
+      end: { column: 8, line: 2 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ",",
+
+    range: [27, 28],
+    loc: {
+      start: { column: 8, line: 2 },
+      end: { column: 9, line: 2 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "{",
+
+    range: [29, 30],
+    loc: {
+      start: { column: 10, line: 2 },
+      end: { column: 11, line: 2 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "}",
+
+    range: [30, 31],
+    loc: {
+      start: { column: 11, line: 2 },
+      end: { column: 12, line: 2 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "from",
+
+    range: [32, 36],
+    loc: {
+      start: { column: 13, line: 2 },
+      end: { column: 17, line: 2 },
+    },
+  },
+  String {
+    type: "String",
+    value: "'mod'",
+
+    range: [37, 42],
+    loc: {
+      start: { column: 18, line: 2 },
+      end: { column: 23, line: 2 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ";",
+
+    range: [42, 43],
+    loc: {
+      start: { column: 23, line: 2 },
+      end: { column: 24, line: 2 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default-and-named-none/snapshots/5-AST-Alignment-AST.shot b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default-and-named-none/snapshots/5-AST-Alignment-AST.shot
new file mode 100644
index 000000000000..77b9d9ec72bc
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default-and-named-none/snapshots/5-AST-Alignment-AST.shot
@@ -0,0 +1,6 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ImportDeclaration default-and-named-none AST Alignment - AST 1`] = `
+"Snapshot Diff:
+Compared values have no visual difference."
+`;
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default-and-named-none/snapshots/6-AST-Alignment-Tokens.shot b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default-and-named-none/snapshots/6-AST-Alignment-Tokens.shot
new file mode 100644
index 000000000000..db5dec353c24
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default-and-named-none/snapshots/6-AST-Alignment-Tokens.shot
@@ -0,0 +1,6 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ImportDeclaration default-and-named-none AST Alignment - Token 1`] = `
+"Snapshot Diff:
+Compared values have no visual difference."
+`;
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default-and-named-one/fixture.ts b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default-and-named-one/fixture.ts
new file mode 100644
index 000000000000..5e938031ed6f
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default-and-named-one/fixture.ts
@@ -0,0 +1 @@
+import a, { b } from 'mod';
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default-and-named-one/snapshots/1-TSESTree-AST.shot b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default-and-named-one/snapshots/1-TSESTree-AST.shot
new file mode 100644
index 000000000000..362d429e0274
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default-and-named-one/snapshots/1-TSESTree-AST.shot
@@ -0,0 +1,89 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ImportDeclaration default-and-named-one TSESTree - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    ImportDeclaration {
+      type: "ImportDeclaration",
+      assertions: Array [],
+      importKind: "value",
+      source: Literal {
+        type: "Literal",
+        raw: "'mod'",
+        value: "mod",
+
+        range: [21, 26],
+        loc: {
+          start: { column: 21, line: 1 },
+          end: { column: 26, line: 1 },
+        },
+      },
+      specifiers: Array [
+        ImportDefaultSpecifier {
+          type: "ImportDefaultSpecifier",
+          local: Identifier {
+            type: "Identifier",
+            name: "a",
+
+            range: [7, 8],
+            loc: {
+              start: { column: 7, line: 1 },
+              end: { column: 8, line: 1 },
+            },
+          },
+
+          range: [7, 8],
+          loc: {
+            start: { column: 7, line: 1 },
+            end: { column: 8, line: 1 },
+          },
+        },
+        ImportSpecifier {
+          type: "ImportSpecifier",
+          imported: Identifier {
+            type: "Identifier",
+            name: "b",
+
+            range: [12, 13],
+            loc: {
+              start: { column: 12, line: 1 },
+              end: { column: 13, line: 1 },
+            },
+          },
+          importKind: "value",
+          local: Identifier {
+            type: "Identifier",
+            name: "b",
+
+            range: [12, 13],
+            loc: {
+              start: { column: 12, line: 1 },
+              end: { column: 13, line: 1 },
+            },
+          },
+
+          range: [12, 13],
+          loc: {
+            start: { column: 12, line: 1 },
+            end: { column: 13, line: 1 },
+          },
+        },
+      ],
+
+      range: [0, 27],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 27, line: 1 },
+      },
+    },
+  ],
+  sourceType: "module",
+
+  range: [0, 28],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default-and-named-one/snapshots/2-TSESTree-Tokens.shot b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default-and-named-one/snapshots/2-TSESTree-Tokens.shot
new file mode 100644
index 000000000000..99806f28e2f1
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default-and-named-one/snapshots/2-TSESTree-Tokens.shot
@@ -0,0 +1,96 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ImportDeclaration default-and-named-one TSESTree - Tokens 1`] = `
+Array [
+  Keyword {
+    type: "Keyword",
+    value: "import",
+
+    range: [0, 6],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 6, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "a",
+
+    range: [7, 8],
+    loc: {
+      start: { column: 7, line: 1 },
+      end: { column: 8, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ",",
+
+    range: [8, 9],
+    loc: {
+      start: { column: 8, line: 1 },
+      end: { column: 9, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "{",
+
+    range: [10, 11],
+    loc: {
+      start: { column: 10, line: 1 },
+      end: { column: 11, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "b",
+
+    range: [12, 13],
+    loc: {
+      start: { column: 12, line: 1 },
+      end: { column: 13, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "}",
+
+    range: [14, 15],
+    loc: {
+      start: { column: 14, line: 1 },
+      end: { column: 15, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "from",
+
+    range: [16, 20],
+    loc: {
+      start: { column: 16, line: 1 },
+      end: { column: 20, line: 1 },
+    },
+  },
+  String {
+    type: "String",
+    value: "'mod'",
+
+    range: [21, 26],
+    loc: {
+      start: { column: 21, line: 1 },
+      end: { column: 26, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ";",
+
+    range: [26, 27],
+    loc: {
+      start: { column: 26, line: 1 },
+      end: { column: 27, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default-and-named-one/snapshots/3-Babel-AST.shot b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default-and-named-one/snapshots/3-Babel-AST.shot
new file mode 100644
index 000000000000..45b6d3ec61ed
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default-and-named-one/snapshots/3-Babel-AST.shot
@@ -0,0 +1,89 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ImportDeclaration default-and-named-one Babel - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    ImportDeclaration {
+      type: "ImportDeclaration",
+      assertions: Array [],
+      importKind: "value",
+      source: Literal {
+        type: "Literal",
+        raw: "'mod'",
+        value: "mod",
+
+        range: [21, 26],
+        loc: {
+          start: { column: 21, line: 1 },
+          end: { column: 26, line: 1 },
+        },
+      },
+      specifiers: Array [
+        ImportDefaultSpecifier {
+          type: "ImportDefaultSpecifier",
+          local: Identifier {
+            type: "Identifier",
+            name: "a",
+
+            range: [7, 8],
+            loc: {
+              start: { column: 7, line: 1 },
+              end: { column: 8, line: 1 },
+            },
+          },
+
+          range: [7, 8],
+          loc: {
+            start: { column: 7, line: 1 },
+            end: { column: 8, line: 1 },
+          },
+        },
+        ImportSpecifier {
+          type: "ImportSpecifier",
+          imported: Identifier {
+            type: "Identifier",
+            name: "b",
+
+            range: [12, 13],
+            loc: {
+              start: { column: 12, line: 1 },
+              end: { column: 13, line: 1 },
+            },
+          },
+          importKind: "value",
+          local: Identifier {
+            type: "Identifier",
+            name: "b",
+
+            range: [12, 13],
+            loc: {
+              start: { column: 12, line: 1 },
+              end: { column: 13, line: 1 },
+            },
+          },
+
+          range: [12, 13],
+          loc: {
+            start: { column: 12, line: 1 },
+            end: { column: 13, line: 1 },
+          },
+        },
+      ],
+
+      range: [0, 27],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 27, line: 1 },
+      },
+    },
+  ],
+  sourceType: "module",
+
+  range: [0, 28],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default-and-named-one/snapshots/4-Babel-Tokens.shot b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default-and-named-one/snapshots/4-Babel-Tokens.shot
new file mode 100644
index 000000000000..e11fa0be693a
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default-and-named-one/snapshots/4-Babel-Tokens.shot
@@ -0,0 +1,96 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ImportDeclaration default-and-named-one Babel - Tokens 1`] = `
+Array [
+  Keyword {
+    type: "Keyword",
+    value: "import",
+
+    range: [0, 6],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 6, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "a",
+
+    range: [7, 8],
+    loc: {
+      start: { column: 7, line: 1 },
+      end: { column: 8, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ",",
+
+    range: [8, 9],
+    loc: {
+      start: { column: 8, line: 1 },
+      end: { column: 9, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "{",
+
+    range: [10, 11],
+    loc: {
+      start: { column: 10, line: 1 },
+      end: { column: 11, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "b",
+
+    range: [12, 13],
+    loc: {
+      start: { column: 12, line: 1 },
+      end: { column: 13, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "}",
+
+    range: [14, 15],
+    loc: {
+      start: { column: 14, line: 1 },
+      end: { column: 15, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "from",
+
+    range: [16, 20],
+    loc: {
+      start: { column: 16, line: 1 },
+      end: { column: 20, line: 1 },
+    },
+  },
+  String {
+    type: "String",
+    value: "'mod'",
+
+    range: [21, 26],
+    loc: {
+      start: { column: 21, line: 1 },
+      end: { column: 26, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ";",
+
+    range: [26, 27],
+    loc: {
+      start: { column: 26, line: 1 },
+      end: { column: 27, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default-and-named-one/snapshots/5-AST-Alignment-AST.shot b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default-and-named-one/snapshots/5-AST-Alignment-AST.shot
new file mode 100644
index 000000000000..8661b6d43b20
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default-and-named-one/snapshots/5-AST-Alignment-AST.shot
@@ -0,0 +1,6 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ImportDeclaration default-and-named-one AST Alignment - AST 1`] = `
+"Snapshot Diff:
+Compared values have no visual difference."
+`;
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default-and-named-one/snapshots/6-AST-Alignment-Tokens.shot b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default-and-named-one/snapshots/6-AST-Alignment-Tokens.shot
new file mode 100644
index 000000000000..8f0c817495a3
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default-and-named-one/snapshots/6-AST-Alignment-Tokens.shot
@@ -0,0 +1,6 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ImportDeclaration default-and-named-one AST Alignment - Token 1`] = `
+"Snapshot Diff:
+Compared values have no visual difference."
+`;
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default-and-namespace/fixture.ts b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default-and-namespace/fixture.ts
new file mode 100644
index 000000000000..e18354616a73
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default-and-namespace/fixture.ts
@@ -0,0 +1 @@
+import a, * as b from 'mod';
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default-and-namespace/snapshots/1-TSESTree-AST.shot b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default-and-namespace/snapshots/1-TSESTree-AST.shot
new file mode 100644
index 000000000000..88c4eac8c154
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default-and-namespace/snapshots/1-TSESTree-AST.shot
@@ -0,0 +1,78 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ImportDeclaration default-and-namespace TSESTree - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    ImportDeclaration {
+      type: "ImportDeclaration",
+      assertions: Array [],
+      importKind: "value",
+      source: Literal {
+        type: "Literal",
+        raw: "'mod'",
+        value: "mod",
+
+        range: [22, 27],
+        loc: {
+          start: { column: 22, line: 1 },
+          end: { column: 27, line: 1 },
+        },
+      },
+      specifiers: Array [
+        ImportDefaultSpecifier {
+          type: "ImportDefaultSpecifier",
+          local: Identifier {
+            type: "Identifier",
+            name: "a",
+
+            range: [7, 8],
+            loc: {
+              start: { column: 7, line: 1 },
+              end: { column: 8, line: 1 },
+            },
+          },
+
+          range: [7, 8],
+          loc: {
+            start: { column: 7, line: 1 },
+            end: { column: 8, line: 1 },
+          },
+        },
+        ImportNamespaceSpecifier {
+          type: "ImportNamespaceSpecifier",
+          local: Identifier {
+            type: "Identifier",
+            name: "b",
+
+            range: [15, 16],
+            loc: {
+              start: { column: 15, line: 1 },
+              end: { column: 16, line: 1 },
+            },
+          },
+
+          range: [10, 16],
+          loc: {
+            start: { column: 10, line: 1 },
+            end: { column: 16, line: 1 },
+          },
+        },
+      ],
+
+      range: [0, 28],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 28, line: 1 },
+      },
+    },
+  ],
+  sourceType: "module",
+
+  range: [0, 29],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default-and-namespace/snapshots/2-TSESTree-Tokens.shot b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default-and-namespace/snapshots/2-TSESTree-Tokens.shot
new file mode 100644
index 000000000000..f78a2e961787
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default-and-namespace/snapshots/2-TSESTree-Tokens.shot
@@ -0,0 +1,96 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ImportDeclaration default-and-namespace TSESTree - Tokens 1`] = `
+Array [
+  Keyword {
+    type: "Keyword",
+    value: "import",
+
+    range: [0, 6],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 6, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "a",
+
+    range: [7, 8],
+    loc: {
+      start: { column: 7, line: 1 },
+      end: { column: 8, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ",",
+
+    range: [8, 9],
+    loc: {
+      start: { column: 8, line: 1 },
+      end: { column: 9, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "*",
+
+    range: [10, 11],
+    loc: {
+      start: { column: 10, line: 1 },
+      end: { column: 11, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "as",
+
+    range: [12, 14],
+    loc: {
+      start: { column: 12, line: 1 },
+      end: { column: 14, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "b",
+
+    range: [15, 16],
+    loc: {
+      start: { column: 15, line: 1 },
+      end: { column: 16, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "from",
+
+    range: [17, 21],
+    loc: {
+      start: { column: 17, line: 1 },
+      end: { column: 21, line: 1 },
+    },
+  },
+  String {
+    type: "String",
+    value: "'mod'",
+
+    range: [22, 27],
+    loc: {
+      start: { column: 22, line: 1 },
+      end: { column: 27, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ";",
+
+    range: [27, 28],
+    loc: {
+      start: { column: 27, line: 1 },
+      end: { column: 28, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default-and-namespace/snapshots/3-Babel-AST.shot b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default-and-namespace/snapshots/3-Babel-AST.shot
new file mode 100644
index 000000000000..25d8c6db0a39
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default-and-namespace/snapshots/3-Babel-AST.shot
@@ -0,0 +1,78 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ImportDeclaration default-and-namespace Babel - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    ImportDeclaration {
+      type: "ImportDeclaration",
+      assertions: Array [],
+      importKind: "value",
+      source: Literal {
+        type: "Literal",
+        raw: "'mod'",
+        value: "mod",
+
+        range: [22, 27],
+        loc: {
+          start: { column: 22, line: 1 },
+          end: { column: 27, line: 1 },
+        },
+      },
+      specifiers: Array [
+        ImportDefaultSpecifier {
+          type: "ImportDefaultSpecifier",
+          local: Identifier {
+            type: "Identifier",
+            name: "a",
+
+            range: [7, 8],
+            loc: {
+              start: { column: 7, line: 1 },
+              end: { column: 8, line: 1 },
+            },
+          },
+
+          range: [7, 8],
+          loc: {
+            start: { column: 7, line: 1 },
+            end: { column: 8, line: 1 },
+          },
+        },
+        ImportNamespaceSpecifier {
+          type: "ImportNamespaceSpecifier",
+          local: Identifier {
+            type: "Identifier",
+            name: "b",
+
+            range: [15, 16],
+            loc: {
+              start: { column: 15, line: 1 },
+              end: { column: 16, line: 1 },
+            },
+          },
+
+          range: [10, 16],
+          loc: {
+            start: { column: 10, line: 1 },
+            end: { column: 16, line: 1 },
+          },
+        },
+      ],
+
+      range: [0, 28],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 28, line: 1 },
+      },
+    },
+  ],
+  sourceType: "module",
+
+  range: [0, 29],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default-and-namespace/snapshots/4-Babel-Tokens.shot b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default-and-namespace/snapshots/4-Babel-Tokens.shot
new file mode 100644
index 000000000000..b6bc0f06e1d4
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default-and-namespace/snapshots/4-Babel-Tokens.shot
@@ -0,0 +1,96 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ImportDeclaration default-and-namespace Babel - Tokens 1`] = `
+Array [
+  Keyword {
+    type: "Keyword",
+    value: "import",
+
+    range: [0, 6],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 6, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "a",
+
+    range: [7, 8],
+    loc: {
+      start: { column: 7, line: 1 },
+      end: { column: 8, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ",",
+
+    range: [8, 9],
+    loc: {
+      start: { column: 8, line: 1 },
+      end: { column: 9, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "*",
+
+    range: [10, 11],
+    loc: {
+      start: { column: 10, line: 1 },
+      end: { column: 11, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "as",
+
+    range: [12, 14],
+    loc: {
+      start: { column: 12, line: 1 },
+      end: { column: 14, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "b",
+
+    range: [15, 16],
+    loc: {
+      start: { column: 15, line: 1 },
+      end: { column: 16, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "from",
+
+    range: [17, 21],
+    loc: {
+      start: { column: 17, line: 1 },
+      end: { column: 21, line: 1 },
+    },
+  },
+  String {
+    type: "String",
+    value: "'mod'",
+
+    range: [22, 27],
+    loc: {
+      start: { column: 22, line: 1 },
+      end: { column: 27, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ";",
+
+    range: [27, 28],
+    loc: {
+      start: { column: 27, line: 1 },
+      end: { column: 28, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default-and-namespace/snapshots/5-AST-Alignment-AST.shot b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default-and-namespace/snapshots/5-AST-Alignment-AST.shot
new file mode 100644
index 000000000000..c975ae691183
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default-and-namespace/snapshots/5-AST-Alignment-AST.shot
@@ -0,0 +1,6 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ImportDeclaration default-and-namespace AST Alignment - AST 1`] = `
+"Snapshot Diff:
+Compared values have no visual difference."
+`;
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default-and-namespace/snapshots/6-AST-Alignment-Tokens.shot b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default-and-namespace/snapshots/6-AST-Alignment-Tokens.shot
new file mode 100644
index 000000000000..2ea3772b5fc8
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default-and-namespace/snapshots/6-AST-Alignment-Tokens.shot
@@ -0,0 +1,6 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ImportDeclaration default-and-namespace AST Alignment - Token 1`] = `
+"Snapshot Diff:
+Compared values have no visual difference."
+`;
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default/fixture.ts b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default/fixture.ts
new file mode 100644
index 000000000000..b4fa44ea4352
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default/fixture.ts
@@ -0,0 +1 @@
+import a from 'mod';
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default/snapshots/1-TSESTree-AST.shot b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default/snapshots/1-TSESTree-AST.shot
new file mode 100644
index 000000000000..8575ecc99e21
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default/snapshots/1-TSESTree-AST.shot
@@ -0,0 +1,59 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ImportDeclaration default TSESTree - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    ImportDeclaration {
+      type: "ImportDeclaration",
+      assertions: Array [],
+      importKind: "value",
+      source: Literal {
+        type: "Literal",
+        raw: "'mod'",
+        value: "mod",
+
+        range: [14, 19],
+        loc: {
+          start: { column: 14, line: 1 },
+          end: { column: 19, line: 1 },
+        },
+      },
+      specifiers: Array [
+        ImportDefaultSpecifier {
+          type: "ImportDefaultSpecifier",
+          local: Identifier {
+            type: "Identifier",
+            name: "a",
+
+            range: [7, 8],
+            loc: {
+              start: { column: 7, line: 1 },
+              end: { column: 8, line: 1 },
+            },
+          },
+
+          range: [7, 8],
+          loc: {
+            start: { column: 7, line: 1 },
+            end: { column: 8, line: 1 },
+          },
+        },
+      ],
+
+      range: [0, 20],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 20, line: 1 },
+      },
+    },
+  ],
+  sourceType: "module",
+
+  range: [0, 21],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default/snapshots/2-TSESTree-Tokens.shot b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default/snapshots/2-TSESTree-Tokens.shot
new file mode 100644
index 000000000000..b2ac2cf753d1
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default/snapshots/2-TSESTree-Tokens.shot
@@ -0,0 +1,56 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ImportDeclaration default TSESTree - Tokens 1`] = `
+Array [
+  Keyword {
+    type: "Keyword",
+    value: "import",
+
+    range: [0, 6],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 6, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "a",
+
+    range: [7, 8],
+    loc: {
+      start: { column: 7, line: 1 },
+      end: { column: 8, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "from",
+
+    range: [9, 13],
+    loc: {
+      start: { column: 9, line: 1 },
+      end: { column: 13, line: 1 },
+    },
+  },
+  String {
+    type: "String",
+    value: "'mod'",
+
+    range: [14, 19],
+    loc: {
+      start: { column: 14, line: 1 },
+      end: { column: 19, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ";",
+
+    range: [19, 20],
+    loc: {
+      start: { column: 19, line: 1 },
+      end: { column: 20, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default/snapshots/3-Babel-AST.shot b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default/snapshots/3-Babel-AST.shot
new file mode 100644
index 000000000000..bfb44b15fa6e
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default/snapshots/3-Babel-AST.shot
@@ -0,0 +1,59 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ImportDeclaration default Babel - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    ImportDeclaration {
+      type: "ImportDeclaration",
+      assertions: Array [],
+      importKind: "value",
+      source: Literal {
+        type: "Literal",
+        raw: "'mod'",
+        value: "mod",
+
+        range: [14, 19],
+        loc: {
+          start: { column: 14, line: 1 },
+          end: { column: 19, line: 1 },
+        },
+      },
+      specifiers: Array [
+        ImportDefaultSpecifier {
+          type: "ImportDefaultSpecifier",
+          local: Identifier {
+            type: "Identifier",
+            name: "a",
+
+            range: [7, 8],
+            loc: {
+              start: { column: 7, line: 1 },
+              end: { column: 8, line: 1 },
+            },
+          },
+
+          range: [7, 8],
+          loc: {
+            start: { column: 7, line: 1 },
+            end: { column: 8, line: 1 },
+          },
+        },
+      ],
+
+      range: [0, 20],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 20, line: 1 },
+      },
+    },
+  ],
+  sourceType: "module",
+
+  range: [0, 21],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default/snapshots/4-Babel-Tokens.shot b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default/snapshots/4-Babel-Tokens.shot
new file mode 100644
index 000000000000..e5c09dd423ed
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default/snapshots/4-Babel-Tokens.shot
@@ -0,0 +1,56 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ImportDeclaration default Babel - Tokens 1`] = `
+Array [
+  Keyword {
+    type: "Keyword",
+    value: "import",
+
+    range: [0, 6],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 6, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "a",
+
+    range: [7, 8],
+    loc: {
+      start: { column: 7, line: 1 },
+      end: { column: 8, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "from",
+
+    range: [9, 13],
+    loc: {
+      start: { column: 9, line: 1 },
+      end: { column: 13, line: 1 },
+    },
+  },
+  String {
+    type: "String",
+    value: "'mod'",
+
+    range: [14, 19],
+    loc: {
+      start: { column: 14, line: 1 },
+      end: { column: 19, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ";",
+
+    range: [19, 20],
+    loc: {
+      start: { column: 19, line: 1 },
+      end: { column: 20, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default/snapshots/5-AST-Alignment-AST.shot b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default/snapshots/5-AST-Alignment-AST.shot
new file mode 100644
index 000000000000..2524045a8077
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default/snapshots/5-AST-Alignment-AST.shot
@@ -0,0 +1,6 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ImportDeclaration default AST Alignment - AST 1`] = `
+"Snapshot Diff:
+Compared values have no visual difference."
+`;
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default/snapshots/6-AST-Alignment-Tokens.shot b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default/snapshots/6-AST-Alignment-Tokens.shot
new file mode 100644
index 000000000000..75669766d635
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/default/snapshots/6-AST-Alignment-Tokens.shot
@@ -0,0 +1,6 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ImportDeclaration default AST Alignment - Token 1`] = `
+"Snapshot Diff:
+Compared values have no visual difference."
+`;
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/named-many/fixture.ts b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/named-many/fixture.ts
new file mode 100644
index 000000000000..4c8852af5629
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/named-many/fixture.ts
@@ -0,0 +1 @@
+import { a, b, c } from 'mod';
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/named-many/snapshots/1-TSESTree-AST.shot b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/named-many/snapshots/1-TSESTree-AST.shot
new file mode 100644
index 000000000000..a90f8ca955ae
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/named-many/snapshots/1-TSESTree-AST.shot
@@ -0,0 +1,130 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ImportDeclaration named-many TSESTree - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    ImportDeclaration {
+      type: "ImportDeclaration",
+      assertions: Array [],
+      importKind: "value",
+      source: Literal {
+        type: "Literal",
+        raw: "'mod'",
+        value: "mod",
+
+        range: [24, 29],
+        loc: {
+          start: { column: 24, line: 1 },
+          end: { column: 29, line: 1 },
+        },
+      },
+      specifiers: Array [
+        ImportSpecifier {
+          type: "ImportSpecifier",
+          imported: Identifier {
+            type: "Identifier",
+            name: "a",
+
+            range: [9, 10],
+            loc: {
+              start: { column: 9, line: 1 },
+              end: { column: 10, line: 1 },
+            },
+          },
+          importKind: "value",
+          local: Identifier {
+            type: "Identifier",
+            name: "a",
+
+            range: [9, 10],
+            loc: {
+              start: { column: 9, line: 1 },
+              end: { column: 10, line: 1 },
+            },
+          },
+
+          range: [9, 10],
+          loc: {
+            start: { column: 9, line: 1 },
+            end: { column: 10, line: 1 },
+          },
+        },
+        ImportSpecifier {
+          type: "ImportSpecifier",
+          imported: Identifier {
+            type: "Identifier",
+            name: "b",
+
+            range: [12, 13],
+            loc: {
+              start: { column: 12, line: 1 },
+              end: { column: 13, line: 1 },
+            },
+          },
+          importKind: "value",
+          local: Identifier {
+            type: "Identifier",
+            name: "b",
+
+            range: [12, 13],
+            loc: {
+              start: { column: 12, line: 1 },
+              end: { column: 13, line: 1 },
+            },
+          },
+
+          range: [12, 13],
+          loc: {
+            start: { column: 12, line: 1 },
+            end: { column: 13, line: 1 },
+          },
+        },
+        ImportSpecifier {
+          type: "ImportSpecifier",
+          imported: Identifier {
+            type: "Identifier",
+            name: "c",
+
+            range: [15, 16],
+            loc: {
+              start: { column: 15, line: 1 },
+              end: { column: 16, line: 1 },
+            },
+          },
+          importKind: "value",
+          local: Identifier {
+            type: "Identifier",
+            name: "c",
+
+            range: [15, 16],
+            loc: {
+              start: { column: 15, line: 1 },
+              end: { column: 16, line: 1 },
+            },
+          },
+
+          range: [15, 16],
+          loc: {
+            start: { column: 15, line: 1 },
+            end: { column: 16, line: 1 },
+          },
+        },
+      ],
+
+      range: [0, 30],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 30, line: 1 },
+      },
+    },
+  ],
+  sourceType: "module",
+
+  range: [0, 31],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/named-many/snapshots/2-TSESTree-Tokens.shot b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/named-many/snapshots/2-TSESTree-Tokens.shot
new file mode 100644
index 000000000000..8eba9974a714
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/named-many/snapshots/2-TSESTree-Tokens.shot
@@ -0,0 +1,116 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ImportDeclaration named-many TSESTree - Tokens 1`] = `
+Array [
+  Keyword {
+    type: "Keyword",
+    value: "import",
+
+    range: [0, 6],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 6, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "{",
+
+    range: [7, 8],
+    loc: {
+      start: { column: 7, line: 1 },
+      end: { column: 8, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "a",
+
+    range: [9, 10],
+    loc: {
+      start: { column: 9, line: 1 },
+      end: { column: 10, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ",",
+
+    range: [10, 11],
+    loc: {
+      start: { column: 10, line: 1 },
+      end: { column: 11, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "b",
+
+    range: [12, 13],
+    loc: {
+      start: { column: 12, line: 1 },
+      end: { column: 13, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ",",
+
+    range: [13, 14],
+    loc: {
+      start: { column: 13, line: 1 },
+      end: { column: 14, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "c",
+
+    range: [15, 16],
+    loc: {
+      start: { column: 15, line: 1 },
+      end: { column: 16, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "}",
+
+    range: [17, 18],
+    loc: {
+      start: { column: 17, line: 1 },
+      end: { column: 18, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "from",
+
+    range: [19, 23],
+    loc: {
+      start: { column: 19, line: 1 },
+      end: { column: 23, line: 1 },
+    },
+  },
+  String {
+    type: "String",
+    value: "'mod'",
+
+    range: [24, 29],
+    loc: {
+      start: { column: 24, line: 1 },
+      end: { column: 29, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ";",
+
+    range: [29, 30],
+    loc: {
+      start: { column: 29, line: 1 },
+      end: { column: 30, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/named-many/snapshots/3-Babel-AST.shot b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/named-many/snapshots/3-Babel-AST.shot
new file mode 100644
index 000000000000..89d89d705a6f
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/named-many/snapshots/3-Babel-AST.shot
@@ -0,0 +1,130 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ImportDeclaration named-many Babel - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    ImportDeclaration {
+      type: "ImportDeclaration",
+      assertions: Array [],
+      importKind: "value",
+      source: Literal {
+        type: "Literal",
+        raw: "'mod'",
+        value: "mod",
+
+        range: [24, 29],
+        loc: {
+          start: { column: 24, line: 1 },
+          end: { column: 29, line: 1 },
+        },
+      },
+      specifiers: Array [
+        ImportSpecifier {
+          type: "ImportSpecifier",
+          imported: Identifier {
+            type: "Identifier",
+            name: "a",
+
+            range: [9, 10],
+            loc: {
+              start: { column: 9, line: 1 },
+              end: { column: 10, line: 1 },
+            },
+          },
+          importKind: "value",
+          local: Identifier {
+            type: "Identifier",
+            name: "a",
+
+            range: [9, 10],
+            loc: {
+              start: { column: 9, line: 1 },
+              end: { column: 10, line: 1 },
+            },
+          },
+
+          range: [9, 10],
+          loc: {
+            start: { column: 9, line: 1 },
+            end: { column: 10, line: 1 },
+          },
+        },
+        ImportSpecifier {
+          type: "ImportSpecifier",
+          imported: Identifier {
+            type: "Identifier",
+            name: "b",
+
+            range: [12, 13],
+            loc: {
+              start: { column: 12, line: 1 },
+              end: { column: 13, line: 1 },
+            },
+          },
+          importKind: "value",
+          local: Identifier {
+            type: "Identifier",
+            name: "b",
+
+            range: [12, 13],
+            loc: {
+              start: { column: 12, line: 1 },
+              end: { column: 13, line: 1 },
+            },
+          },
+
+          range: [12, 13],
+          loc: {
+            start: { column: 12, line: 1 },
+            end: { column: 13, line: 1 },
+          },
+        },
+        ImportSpecifier {
+          type: "ImportSpecifier",
+          imported: Identifier {
+            type: "Identifier",
+            name: "c",
+
+            range: [15, 16],
+            loc: {
+              start: { column: 15, line: 1 },
+              end: { column: 16, line: 1 },
+            },
+          },
+          importKind: "value",
+          local: Identifier {
+            type: "Identifier",
+            name: "c",
+
+            range: [15, 16],
+            loc: {
+              start: { column: 15, line: 1 },
+              end: { column: 16, line: 1 },
+            },
+          },
+
+          range: [15, 16],
+          loc: {
+            start: { column: 15, line: 1 },
+            end: { column: 16, line: 1 },
+          },
+        },
+      ],
+
+      range: [0, 30],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 30, line: 1 },
+      },
+    },
+  ],
+  sourceType: "module",
+
+  range: [0, 31],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/named-many/snapshots/4-Babel-Tokens.shot b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/named-many/snapshots/4-Babel-Tokens.shot
new file mode 100644
index 000000000000..123471f1513f
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/named-many/snapshots/4-Babel-Tokens.shot
@@ -0,0 +1,116 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ImportDeclaration named-many Babel - Tokens 1`] = `
+Array [
+  Keyword {
+    type: "Keyword",
+    value: "import",
+
+    range: [0, 6],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 6, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "{",
+
+    range: [7, 8],
+    loc: {
+      start: { column: 7, line: 1 },
+      end: { column: 8, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "a",
+
+    range: [9, 10],
+    loc: {
+      start: { column: 9, line: 1 },
+      end: { column: 10, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ",",
+
+    range: [10, 11],
+    loc: {
+      start: { column: 10, line: 1 },
+      end: { column: 11, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "b",
+
+    range: [12, 13],
+    loc: {
+      start: { column: 12, line: 1 },
+      end: { column: 13, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ",",
+
+    range: [13, 14],
+    loc: {
+      start: { column: 13, line: 1 },
+      end: { column: 14, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "c",
+
+    range: [15, 16],
+    loc: {
+      start: { column: 15, line: 1 },
+      end: { column: 16, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "}",
+
+    range: [17, 18],
+    loc: {
+      start: { column: 17, line: 1 },
+      end: { column: 18, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "from",
+
+    range: [19, 23],
+    loc: {
+      start: { column: 19, line: 1 },
+      end: { column: 23, line: 1 },
+    },
+  },
+  String {
+    type: "String",
+    value: "'mod'",
+
+    range: [24, 29],
+    loc: {
+      start: { column: 24, line: 1 },
+      end: { column: 29, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ";",
+
+    range: [29, 30],
+    loc: {
+      start: { column: 29, line: 1 },
+      end: { column: 30, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/named-many/snapshots/5-AST-Alignment-AST.shot b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/named-many/snapshots/5-AST-Alignment-AST.shot
new file mode 100644
index 000000000000..3f4b4b678e7d
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/named-many/snapshots/5-AST-Alignment-AST.shot
@@ -0,0 +1,6 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ImportDeclaration named-many AST Alignment - AST 1`] = `
+"Snapshot Diff:
+Compared values have no visual difference."
+`;
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/named-many/snapshots/6-AST-Alignment-Tokens.shot b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/named-many/snapshots/6-AST-Alignment-Tokens.shot
new file mode 100644
index 000000000000..254949c9452f
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/named-many/snapshots/6-AST-Alignment-Tokens.shot
@@ -0,0 +1,6 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ImportDeclaration named-many AST Alignment - Token 1`] = `
+"Snapshot Diff:
+Compared values have no visual difference."
+`;
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/named-none/fixture.ts b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/named-none/fixture.ts
new file mode 100644
index 000000000000..421d8a81af3f
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/named-none/fixture.ts
@@ -0,0 +1 @@
+import {} from 'mod';
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/named-none/snapshots/1-TSESTree-AST.shot b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/named-none/snapshots/1-TSESTree-AST.shot
new file mode 100644
index 000000000000..12f54a5140e9
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/named-none/snapshots/1-TSESTree-AST.shot
@@ -0,0 +1,39 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ImportDeclaration named-none TSESTree - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    ImportDeclaration {
+      type: "ImportDeclaration",
+      assertions: Array [],
+      importKind: "value",
+      source: Literal {
+        type: "Literal",
+        raw: "'mod'",
+        value: "mod",
+
+        range: [15, 20],
+        loc: {
+          start: { column: 15, line: 1 },
+          end: { column: 20, line: 1 },
+        },
+      },
+      specifiers: Array [],
+
+      range: [0, 21],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 21, line: 1 },
+      },
+    },
+  ],
+  sourceType: "module",
+
+  range: [0, 22],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/named-none/snapshots/2-TSESTree-Tokens.shot b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/named-none/snapshots/2-TSESTree-Tokens.shot
new file mode 100644
index 000000000000..04c72987e07c
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/named-none/snapshots/2-TSESTree-Tokens.shot
@@ -0,0 +1,66 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ImportDeclaration named-none TSESTree - Tokens 1`] = `
+Array [
+  Keyword {
+    type: "Keyword",
+    value: "import",
+
+    range: [0, 6],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 6, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "{",
+
+    range: [7, 8],
+    loc: {
+      start: { column: 7, line: 1 },
+      end: { column: 8, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "}",
+
+    range: [8, 9],
+    loc: {
+      start: { column: 8, line: 1 },
+      end: { column: 9, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "from",
+
+    range: [10, 14],
+    loc: {
+      start: { column: 10, line: 1 },
+      end: { column: 14, line: 1 },
+    },
+  },
+  String {
+    type: "String",
+    value: "'mod'",
+
+    range: [15, 20],
+    loc: {
+      start: { column: 15, line: 1 },
+      end: { column: 20, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ";",
+
+    range: [20, 21],
+    loc: {
+      start: { column: 20, line: 1 },
+      end: { column: 21, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/named-none/snapshots/3-Babel-AST.shot b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/named-none/snapshots/3-Babel-AST.shot
new file mode 100644
index 000000000000..cf425c46b79a
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/named-none/snapshots/3-Babel-AST.shot
@@ -0,0 +1,39 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ImportDeclaration named-none Babel - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    ImportDeclaration {
+      type: "ImportDeclaration",
+      assertions: Array [],
+      importKind: "value",
+      source: Literal {
+        type: "Literal",
+        raw: "'mod'",
+        value: "mod",
+
+        range: [15, 20],
+        loc: {
+          start: { column: 15, line: 1 },
+          end: { column: 20, line: 1 },
+        },
+      },
+      specifiers: Array [],
+
+      range: [0, 21],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 21, line: 1 },
+      },
+    },
+  ],
+  sourceType: "module",
+
+  range: [0, 22],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/named-none/snapshots/4-Babel-Tokens.shot b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/named-none/snapshots/4-Babel-Tokens.shot
new file mode 100644
index 000000000000..ec45fb03592b
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/named-none/snapshots/4-Babel-Tokens.shot
@@ -0,0 +1,66 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ImportDeclaration named-none Babel - Tokens 1`] = `
+Array [
+  Keyword {
+    type: "Keyword",
+    value: "import",
+
+    range: [0, 6],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 6, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "{",
+
+    range: [7, 8],
+    loc: {
+      start: { column: 7, line: 1 },
+      end: { column: 8, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "}",
+
+    range: [8, 9],
+    loc: {
+      start: { column: 8, line: 1 },
+      end: { column: 9, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "from",
+
+    range: [10, 14],
+    loc: {
+      start: { column: 10, line: 1 },
+      end: { column: 14, line: 1 },
+    },
+  },
+  String {
+    type: "String",
+    value: "'mod'",
+
+    range: [15, 20],
+    loc: {
+      start: { column: 15, line: 1 },
+      end: { column: 20, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ";",
+
+    range: [20, 21],
+    loc: {
+      start: { column: 20, line: 1 },
+      end: { column: 21, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/named-none/snapshots/5-AST-Alignment-AST.shot b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/named-none/snapshots/5-AST-Alignment-AST.shot
new file mode 100644
index 000000000000..aa52a0d98d1c
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/named-none/snapshots/5-AST-Alignment-AST.shot
@@ -0,0 +1,6 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ImportDeclaration named-none AST Alignment - AST 1`] = `
+"Snapshot Diff:
+Compared values have no visual difference."
+`;
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/named-none/snapshots/6-AST-Alignment-Tokens.shot b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/named-none/snapshots/6-AST-Alignment-Tokens.shot
new file mode 100644
index 000000000000..4f0ab4858e6c
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/named-none/snapshots/6-AST-Alignment-Tokens.shot
@@ -0,0 +1,6 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ImportDeclaration named-none AST Alignment - Token 1`] = `
+"Snapshot Diff:
+Compared values have no visual difference."
+`;
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/named-one/fixture.ts b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/named-one/fixture.ts
new file mode 100644
index 000000000000..7f1f6a4aa225
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/named-one/fixture.ts
@@ -0,0 +1 @@
+import { a } from 'mod';
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/named-one/snapshots/1-TSESTree-AST.shot b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/named-one/snapshots/1-TSESTree-AST.shot
new file mode 100644
index 000000000000..9030519529e6
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/named-one/snapshots/1-TSESTree-AST.shot
@@ -0,0 +1,70 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ImportDeclaration named-one TSESTree - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    ImportDeclaration {
+      type: "ImportDeclaration",
+      assertions: Array [],
+      importKind: "value",
+      source: Literal {
+        type: "Literal",
+        raw: "'mod'",
+        value: "mod",
+
+        range: [18, 23],
+        loc: {
+          start: { column: 18, line: 1 },
+          end: { column: 23, line: 1 },
+        },
+      },
+      specifiers: Array [
+        ImportSpecifier {
+          type: "ImportSpecifier",
+          imported: Identifier {
+            type: "Identifier",
+            name: "a",
+
+            range: [9, 10],
+            loc: {
+              start: { column: 9, line: 1 },
+              end: { column: 10, line: 1 },
+            },
+          },
+          importKind: "value",
+          local: Identifier {
+            type: "Identifier",
+            name: "a",
+
+            range: [9, 10],
+            loc: {
+              start: { column: 9, line: 1 },
+              end: { column: 10, line: 1 },
+            },
+          },
+
+          range: [9, 10],
+          loc: {
+            start: { column: 9, line: 1 },
+            end: { column: 10, line: 1 },
+          },
+        },
+      ],
+
+      range: [0, 24],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 24, line: 1 },
+      },
+    },
+  ],
+  sourceType: "module",
+
+  range: [0, 25],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/named-one/snapshots/2-TSESTree-Tokens.shot b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/named-one/snapshots/2-TSESTree-Tokens.shot
new file mode 100644
index 000000000000..b437ec118b9a
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/named-one/snapshots/2-TSESTree-Tokens.shot
@@ -0,0 +1,76 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ImportDeclaration named-one TSESTree - Tokens 1`] = `
+Array [
+  Keyword {
+    type: "Keyword",
+    value: "import",
+
+    range: [0, 6],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 6, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "{",
+
+    range: [7, 8],
+    loc: {
+      start: { column: 7, line: 1 },
+      end: { column: 8, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "a",
+
+    range: [9, 10],
+    loc: {
+      start: { column: 9, line: 1 },
+      end: { column: 10, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "}",
+
+    range: [11, 12],
+    loc: {
+      start: { column: 11, line: 1 },
+      end: { column: 12, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "from",
+
+    range: [13, 17],
+    loc: {
+      start: { column: 13, line: 1 },
+      end: { column: 17, line: 1 },
+    },
+  },
+  String {
+    type: "String",
+    value: "'mod'",
+
+    range: [18, 23],
+    loc: {
+      start: { column: 18, line: 1 },
+      end: { column: 23, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ";",
+
+    range: [23, 24],
+    loc: {
+      start: { column: 23, line: 1 },
+      end: { column: 24, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/named-one/snapshots/3-Babel-AST.shot b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/named-one/snapshots/3-Babel-AST.shot
new file mode 100644
index 000000000000..6bc6fe7a38b5
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/named-one/snapshots/3-Babel-AST.shot
@@ -0,0 +1,70 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ImportDeclaration named-one Babel - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    ImportDeclaration {
+      type: "ImportDeclaration",
+      assertions: Array [],
+      importKind: "value",
+      source: Literal {
+        type: "Literal",
+        raw: "'mod'",
+        value: "mod",
+
+        range: [18, 23],
+        loc: {
+          start: { column: 18, line: 1 },
+          end: { column: 23, line: 1 },
+        },
+      },
+      specifiers: Array [
+        ImportSpecifier {
+          type: "ImportSpecifier",
+          imported: Identifier {
+            type: "Identifier",
+            name: "a",
+
+            range: [9, 10],
+            loc: {
+              start: { column: 9, line: 1 },
+              end: { column: 10, line: 1 },
+            },
+          },
+          importKind: "value",
+          local: Identifier {
+            type: "Identifier",
+            name: "a",
+
+            range: [9, 10],
+            loc: {
+              start: { column: 9, line: 1 },
+              end: { column: 10, line: 1 },
+            },
+          },
+
+          range: [9, 10],
+          loc: {
+            start: { column: 9, line: 1 },
+            end: { column: 10, line: 1 },
+          },
+        },
+      ],
+
+      range: [0, 24],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 24, line: 1 },
+      },
+    },
+  ],
+  sourceType: "module",
+
+  range: [0, 25],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/named-one/snapshots/4-Babel-Tokens.shot b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/named-one/snapshots/4-Babel-Tokens.shot
new file mode 100644
index 000000000000..fddf4bb21efb
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/named-one/snapshots/4-Babel-Tokens.shot
@@ -0,0 +1,76 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ImportDeclaration named-one Babel - Tokens 1`] = `
+Array [
+  Keyword {
+    type: "Keyword",
+    value: "import",
+
+    range: [0, 6],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 6, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "{",
+
+    range: [7, 8],
+    loc: {
+      start: { column: 7, line: 1 },
+      end: { column: 8, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "a",
+
+    range: [9, 10],
+    loc: {
+      start: { column: 9, line: 1 },
+      end: { column: 10, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "}",
+
+    range: [11, 12],
+    loc: {
+      start: { column: 11, line: 1 },
+      end: { column: 12, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "from",
+
+    range: [13, 17],
+    loc: {
+      start: { column: 13, line: 1 },
+      end: { column: 17, line: 1 },
+    },
+  },
+  String {
+    type: "String",
+    value: "'mod'",
+
+    range: [18, 23],
+    loc: {
+      start: { column: 18, line: 1 },
+      end: { column: 23, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ";",
+
+    range: [23, 24],
+    loc: {
+      start: { column: 23, line: 1 },
+      end: { column: 24, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/named-one/snapshots/5-AST-Alignment-AST.shot b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/named-one/snapshots/5-AST-Alignment-AST.shot
new file mode 100644
index 000000000000..a502907e8f62
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/named-one/snapshots/5-AST-Alignment-AST.shot
@@ -0,0 +1,6 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ImportDeclaration named-one AST Alignment - AST 1`] = `
+"Snapshot Diff:
+Compared values have no visual difference."
+`;
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/named-one/snapshots/6-AST-Alignment-Tokens.shot b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/named-one/snapshots/6-AST-Alignment-Tokens.shot
new file mode 100644
index 000000000000..f1aacd2d411c
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/named-one/snapshots/6-AST-Alignment-Tokens.shot
@@ -0,0 +1,6 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ImportDeclaration named-one AST Alignment - Token 1`] = `
+"Snapshot Diff:
+Compared values have no visual difference."
+`;
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/side-effect/fixture.ts b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/side-effect/fixture.ts
new file mode 100644
index 000000000000..381cd70b72f1
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/side-effect/fixture.ts
@@ -0,0 +1 @@
+import 'mod';
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/side-effect/snapshots/1-TSESTree-AST.shot b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/side-effect/snapshots/1-TSESTree-AST.shot
new file mode 100644
index 000000000000..62da72509bd0
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/side-effect/snapshots/1-TSESTree-AST.shot
@@ -0,0 +1,39 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ImportDeclaration side-effect TSESTree - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    ImportDeclaration {
+      type: "ImportDeclaration",
+      assertions: Array [],
+      importKind: "value",
+      source: Literal {
+        type: "Literal",
+        raw: "'mod'",
+        value: "mod",
+
+        range: [7, 12],
+        loc: {
+          start: { column: 7, line: 1 },
+          end: { column: 12, line: 1 },
+        },
+      },
+      specifiers: Array [],
+
+      range: [0, 13],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 13, line: 1 },
+      },
+    },
+  ],
+  sourceType: "module",
+
+  range: [0, 14],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/side-effect/snapshots/2-TSESTree-Tokens.shot b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/side-effect/snapshots/2-TSESTree-Tokens.shot
new file mode 100644
index 000000000000..dd471c34db4b
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/side-effect/snapshots/2-TSESTree-Tokens.shot
@@ -0,0 +1,36 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ImportDeclaration side-effect TSESTree - Tokens 1`] = `
+Array [
+  Keyword {
+    type: "Keyword",
+    value: "import",
+
+    range: [0, 6],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 6, line: 1 },
+    },
+  },
+  String {
+    type: "String",
+    value: "'mod'",
+
+    range: [7, 12],
+    loc: {
+      start: { column: 7, line: 1 },
+      end: { column: 12, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ";",
+
+    range: [12, 13],
+    loc: {
+      start: { column: 12, line: 1 },
+      end: { column: 13, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/side-effect/snapshots/3-Babel-AST.shot b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/side-effect/snapshots/3-Babel-AST.shot
new file mode 100644
index 000000000000..ab134ebecf8e
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/side-effect/snapshots/3-Babel-AST.shot
@@ -0,0 +1,39 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ImportDeclaration side-effect Babel - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    ImportDeclaration {
+      type: "ImportDeclaration",
+      assertions: Array [],
+      importKind: "value",
+      source: Literal {
+        type: "Literal",
+        raw: "'mod'",
+        value: "mod",
+
+        range: [7, 12],
+        loc: {
+          start: { column: 7, line: 1 },
+          end: { column: 12, line: 1 },
+        },
+      },
+      specifiers: Array [],
+
+      range: [0, 13],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 13, line: 1 },
+      },
+    },
+  ],
+  sourceType: "module",
+
+  range: [0, 14],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/side-effect/snapshots/4-Babel-Tokens.shot b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/side-effect/snapshots/4-Babel-Tokens.shot
new file mode 100644
index 000000000000..d8e354e5b035
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/side-effect/snapshots/4-Babel-Tokens.shot
@@ -0,0 +1,36 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ImportDeclaration side-effect Babel - Tokens 1`] = `
+Array [
+  Keyword {
+    type: "Keyword",
+    value: "import",
+
+    range: [0, 6],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 6, line: 1 },
+    },
+  },
+  String {
+    type: "String",
+    value: "'mod'",
+
+    range: [7, 12],
+    loc: {
+      start: { column: 7, line: 1 },
+      end: { column: 12, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ";",
+
+    range: [12, 13],
+    loc: {
+      start: { column: 12, line: 1 },
+      end: { column: 13, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/side-effect/snapshots/5-AST-Alignment-AST.shot b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/side-effect/snapshots/5-AST-Alignment-AST.shot
new file mode 100644
index 000000000000..2fa96b2dc1ca
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/side-effect/snapshots/5-AST-Alignment-AST.shot
@@ -0,0 +1,6 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ImportDeclaration side-effect AST Alignment - AST 1`] = `
+"Snapshot Diff:
+Compared values have no visual difference."
+`;
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/side-effect/snapshots/6-AST-Alignment-Tokens.shot b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/side-effect/snapshots/6-AST-Alignment-Tokens.shot
new file mode 100644
index 000000000000..1d074a399032
--- /dev/null
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/fixtures/side-effect/snapshots/6-AST-Alignment-Tokens.shot
@@ -0,0 +1,6 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration ImportDeclaration side-effect AST Alignment - Token 1`] = `
+"Snapshot Diff:
+Compared values have no visual difference."
+`;
diff --git a/packages/ast-spec/src/declaration/ImportDeclaration/spec.ts b/packages/ast-spec/src/declaration/ImportDeclaration/spec.ts
index b9689fe2c098..389af77f87a1 100644
--- a/packages/ast-spec/src/declaration/ImportDeclaration/spec.ts
+++ b/packages/ast-spec/src/declaration/ImportDeclaration/spec.ts
@@ -7,8 +7,31 @@ import type { ImportKind } from '../ExportAndImportKind';
 
 export interface ImportDeclaration extends BaseNode {
   type: AST_NODE_TYPES.ImportDeclaration;
+  /**
+   * The assertions declared for the export.
+   * ```
+   * import * from 'mod' assert { type: 'json' };
+   * ```
+   */
+  assertions: ImportAttribute[];
+  /**
+   * The kind of the import.
+   */
+  importKind: ImportKind;
+  /**
+   * The source module being imported from.
+   */
   source: StringLiteral;
+  /**
+   * The specifiers being imported.
+   * If this is an empty array then either there are no specifiers:
+   * ```
+   * import {} from 'mod';
+   * ```
+   * Or it is a side-effect import:
+   * ```
+   * import 'mod';
+   * ```
+   */
   specifiers: ImportClause[];
-  importKind: ImportKind;
-  assertions: ImportAttribute[];
 }
diff --git a/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/_error_/async/fixture.ts b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/_error_/async/fixture.ts
new file mode 100644
index 000000000000..204adf1135a6
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/_error_/async/fixture.ts
@@ -0,0 +1 @@
+declare async function foo();
diff --git a/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/_error_/async/snapshots/1-TSESTree-AST.shot b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/_error_/async/snapshots/1-TSESTree-AST.shot
new file mode 100644
index 000000000000..d01382249a1a
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/_error_/async/snapshots/1-TSESTree-AST.shot
@@ -0,0 +1,40 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSDeclareFunction async TSESTree - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    TSDeclareFunction {
+      type: "TSDeclareFunction",
+      async: true,
+      declare: true,
+      expression: false,
+      generator: false,
+      id: Identifier {
+        type: "Identifier",
+        name: "foo",
+
+        range: [23, 26],
+        loc: {
+          start: { column: 23, line: 1 },
+          end: { column: 26, line: 1 },
+        },
+      },
+      params: Array [],
+
+      range: [0, 29],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 29, line: 1 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 30],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/_error_/async/snapshots/1-TSESTree-Error.shot b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/_error_/async/snapshots/1-TSESTree-Error.shot
new file mode 100644
index 000000000000..79f1c74928b4
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/_error_/async/snapshots/1-TSESTree-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSDeclareFunction _error_ async TSESTree - Error 1`] = `"NO ERROR"`;
diff --git a/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/_error_/async/snapshots/2-Babel-Error.shot b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/_error_/async/snapshots/2-Babel-Error.shot
new file mode 100644
index 000000000000..01db37879fb0
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/_error_/async/snapshots/2-Babel-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSDeclareFunction _error_ async Babel - Error 1`] = `[SyntaxError: Missing semicolon. (1:7)]`;
diff --git a/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/_error_/async/snapshots/2-TSESTree-Tokens.shot b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/_error_/async/snapshots/2-TSESTree-Tokens.shot
new file mode 100644
index 000000000000..57b56f38b089
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/_error_/async/snapshots/2-TSESTree-Tokens.shot
@@ -0,0 +1,76 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSDeclareFunction async TSESTree - Tokens 1`] = `
+Array [
+  Identifier {
+    type: "Identifier",
+    value: "declare",
+
+    range: [0, 7],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 7, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "async",
+
+    range: [8, 13],
+    loc: {
+      start: { column: 8, line: 1 },
+      end: { column: 13, line: 1 },
+    },
+  },
+  Keyword {
+    type: "Keyword",
+    value: "function",
+
+    range: [14, 22],
+    loc: {
+      start: { column: 14, line: 1 },
+      end: { column: 22, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "foo",
+
+    range: [23, 26],
+    loc: {
+      start: { column: 23, line: 1 },
+      end: { column: 26, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "(",
+
+    range: [26, 27],
+    loc: {
+      start: { column: 26, line: 1 },
+      end: { column: 27, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ")",
+
+    range: [27, 28],
+    loc: {
+      start: { column: 27, line: 1 },
+      end: { column: 28, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ";",
+
+    range: [28, 29],
+    loc: {
+      start: { column: 28, line: 1 },
+      end: { column: 29, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/_error_/async/snapshots/3-Alignment-Error.shot b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/_error_/async/snapshots/3-Alignment-Error.shot
new file mode 100644
index 000000000000..1f36cb0955fb
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/_error_/async/snapshots/3-Alignment-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSDeclareFunction _error_ async Error Alignment 1`] = `"Babel errored but TSESTree didn't"`;
diff --git a/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/_error_/declare-with-body/fixture.ts b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/_error_/declare-with-body/fixture.ts
new file mode 100644
index 000000000000..d99be022e46e
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/_error_/declare-with-body/fixture.ts
@@ -0,0 +1 @@
+declare function foo(): void {};
diff --git a/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/_error_/declare-with-body/snapshots/1-TSESTree-Error.shot b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/_error_/declare-with-body/snapshots/1-TSESTree-Error.shot
new file mode 100644
index 000000000000..ca0dba2a0c34
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/_error_/declare-with-body/snapshots/1-TSESTree-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSDeclareFunction _error_ declare-with-body TSESTree - Error 1`] = `"NO ERROR"`;
diff --git a/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/_error_/declare-with-body/snapshots/2-Babel-Error.shot b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/_error_/declare-with-body/snapshots/2-Babel-Error.shot
new file mode 100644
index 000000000000..e56bbb598920
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/_error_/declare-with-body/snapshots/2-Babel-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSDeclareFunction _error_ declare-with-body Babel - Error 1`] = `[SyntaxError: An implementation cannot be declared in ambient contexts. (1:0)]`;
diff --git a/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/_error_/declare-with-body/snapshots/3-Alignment-Error.shot b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/_error_/declare-with-body/snapshots/3-Alignment-Error.shot
new file mode 100644
index 000000000000..22b125b56439
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/_error_/declare-with-body/snapshots/3-Alignment-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSDeclareFunction _error_ declare-with-body Error Alignment 1`] = `"Babel errored but TSESTree didn't"`;
diff --git a/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/_error_/missing-id-and-not-exported/fixture.ts b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/_error_/missing-id-and-not-exported/fixture.ts
new file mode 100644
index 000000000000..9b557f21605c
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/_error_/missing-id-and-not-exported/fixture.ts
@@ -0,0 +1 @@
+declare function ();
diff --git a/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/_error_/missing-id-and-not-exported/snapshots/1-TSESTree-Error.shot b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/_error_/missing-id-and-not-exported/snapshots/1-TSESTree-Error.shot
new file mode 100644
index 000000000000..53a142d37bec
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/_error_/missing-id-and-not-exported/snapshots/1-TSESTree-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSDeclareFunction _error_ missing-id-and-not-exported TSESTree - Error 1`] = `[TSError: Identifier expected.]`;
diff --git a/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/_error_/missing-id-and-not-exported/snapshots/2-Babel-Error.shot b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/_error_/missing-id-and-not-exported/snapshots/2-Babel-Error.shot
new file mode 100644
index 000000000000..bb9716addfbd
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/_error_/missing-id-and-not-exported/snapshots/2-Babel-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSDeclareFunction _error_ missing-id-and-not-exported Babel - Error 1`] = `[SyntaxError: Unexpected token (1:17)]`;
diff --git a/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/_error_/missing-id-and-not-exported/snapshots/3-Alignment-Error.shot b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/_error_/missing-id-and-not-exported/snapshots/3-Alignment-Error.shot
new file mode 100644
index 000000000000..7bd554c552ac
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/_error_/missing-id-and-not-exported/snapshots/3-Alignment-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSDeclareFunction _error_ missing-id-and-not-exported Error Alignment 1`] = `"Both errored"`;
diff --git a/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/_error_/missing-type-param/fixture.ts b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/_error_/missing-type-param/fixture.ts
new file mode 100644
index 000000000000..a209e2670b2f
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/_error_/missing-type-param/fixture.ts
@@ -0,0 +1 @@
+declare function foo<>(): void;
diff --git a/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/_error_/missing-type-param/snapshots/1-TSESTree-Error.shot b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/_error_/missing-type-param/snapshots/1-TSESTree-Error.shot
new file mode 100644
index 000000000000..217a78df58b6
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/_error_/missing-type-param/snapshots/1-TSESTree-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSDeclareFunction _error_ missing-type-param TSESTree - Error 1`] = `"NO ERROR"`;
diff --git a/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/_error_/missing-type-param/snapshots/2-Babel-Error.shot b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/_error_/missing-type-param/snapshots/2-Babel-Error.shot
new file mode 100644
index 000000000000..be819649c559
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/_error_/missing-type-param/snapshots/2-Babel-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSDeclareFunction _error_ missing-type-param Babel - Error 1`] = `[SyntaxError: Type parameter list cannot be empty. (1:20)]`;
diff --git a/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/_error_/missing-type-param/snapshots/3-Alignment-Error.shot b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/_error_/missing-type-param/snapshots/3-Alignment-Error.shot
new file mode 100644
index 000000000000..83fabb4dfc72
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/_error_/missing-type-param/snapshots/3-Alignment-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSDeclareFunction _error_ missing-type-param Error Alignment 1`] = `"Babel errored but TSESTree didn't"`;
diff --git a/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/_error_/non-identifier-name/fixture.ts b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/_error_/non-identifier-name/fixture.ts
new file mode 100644
index 000000000000..15adf45390c7
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/_error_/non-identifier-name/fixture.ts
@@ -0,0 +1 @@
+declare function 1();
diff --git a/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/_error_/non-identifier-name/snapshots/1-TSESTree-Error.shot b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/_error_/non-identifier-name/snapshots/1-TSESTree-Error.shot
new file mode 100644
index 000000000000..86f0f5e5e10e
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/_error_/non-identifier-name/snapshots/1-TSESTree-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSDeclareFunction _error_ non-identifier-name TSESTree - Error 1`] = `[TSError: Identifier expected.]`;
diff --git a/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/_error_/non-identifier-name/snapshots/2-Babel-Error.shot b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/_error_/non-identifier-name/snapshots/2-Babel-Error.shot
new file mode 100644
index 000000000000..12fadb8985a9
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/_error_/non-identifier-name/snapshots/2-Babel-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSDeclareFunction _error_ non-identifier-name Babel - Error 1`] = `[SyntaxError: Unexpected token (1:17)]`;
diff --git a/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/_error_/non-identifier-name/snapshots/3-Alignment-Error.shot b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/_error_/non-identifier-name/snapshots/3-Alignment-Error.shot
new file mode 100644
index 000000000000..0587657ad4e3
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/_error_/non-identifier-name/snapshots/3-Alignment-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSDeclareFunction _error_ non-identifier-name Error Alignment 1`] = `"Both errored"`;
diff --git a/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/_error_/non-identifier-type-param/fixture.ts b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/_error_/non-identifier-type-param/fixture.ts
new file mode 100644
index 000000000000..0143e128d1fe
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/_error_/non-identifier-type-param/fixture.ts
@@ -0,0 +1 @@
+declare function f<1>(): void;
diff --git a/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/_error_/non-identifier-type-param/snapshots/1-TSESTree-Error.shot b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/_error_/non-identifier-type-param/snapshots/1-TSESTree-Error.shot
new file mode 100644
index 000000000000..4b033027f130
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/_error_/non-identifier-type-param/snapshots/1-TSESTree-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSDeclareFunction _error_ non-identifier-type-param TSESTree - Error 1`] = `[TSError: Type parameter declaration expected.]`;
diff --git a/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/_error_/non-identifier-type-param/snapshots/2-Babel-Error.shot b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/_error_/non-identifier-type-param/snapshots/2-Babel-Error.shot
new file mode 100644
index 000000000000..82c36588558a
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/_error_/non-identifier-type-param/snapshots/2-Babel-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSDeclareFunction _error_ non-identifier-type-param Babel - Error 1`] = `[SyntaxError: Unexpected token (1:19)]`;
diff --git a/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/_error_/non-identifier-type-param/snapshots/3-Alignment-Error.shot b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/_error_/non-identifier-type-param/snapshots/3-Alignment-Error.shot
new file mode 100644
index 000000000000..0d57d7e26a4f
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/_error_/non-identifier-type-param/snapshots/3-Alignment-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSDeclareFunction _error_ non-identifier-type-param Error Alignment 1`] = `"Both errored"`;
diff --git a/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/empty/fixture.ts b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/empty/fixture.ts
new file mode 100644
index 000000000000..a55ca703c8e9
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/empty/fixture.ts
@@ -0,0 +1 @@
+declare function foo();
diff --git a/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/empty/snapshots/1-TSESTree-AST.shot b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/empty/snapshots/1-TSESTree-AST.shot
new file mode 100644
index 000000000000..59ea1f2fa4cc
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/empty/snapshots/1-TSESTree-AST.shot
@@ -0,0 +1,40 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSDeclareFunction empty TSESTree - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    TSDeclareFunction {
+      type: "TSDeclareFunction",
+      async: false,
+      declare: true,
+      expression: false,
+      generator: false,
+      id: Identifier {
+        type: "Identifier",
+        name: "foo",
+
+        range: [17, 20],
+        loc: {
+          start: { column: 17, line: 1 },
+          end: { column: 20, line: 1 },
+        },
+      },
+      params: Array [],
+
+      range: [0, 23],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 23, line: 1 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 24],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/empty/snapshots/2-TSESTree-Tokens.shot b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/empty/snapshots/2-TSESTree-Tokens.shot
new file mode 100644
index 000000000000..68ee13556c41
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/empty/snapshots/2-TSESTree-Tokens.shot
@@ -0,0 +1,66 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSDeclareFunction empty TSESTree - Tokens 1`] = `
+Array [
+  Identifier {
+    type: "Identifier",
+    value: "declare",
+
+    range: [0, 7],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 7, line: 1 },
+    },
+  },
+  Keyword {
+    type: "Keyword",
+    value: "function",
+
+    range: [8, 16],
+    loc: {
+      start: { column: 8, line: 1 },
+      end: { column: 16, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "foo",
+
+    range: [17, 20],
+    loc: {
+      start: { column: 17, line: 1 },
+      end: { column: 20, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "(",
+
+    range: [20, 21],
+    loc: {
+      start: { column: 20, line: 1 },
+      end: { column: 21, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ")",
+
+    range: [21, 22],
+    loc: {
+      start: { column: 21, line: 1 },
+      end: { column: 22, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ";",
+
+    range: [22, 23],
+    loc: {
+      start: { column: 22, line: 1 },
+      end: { column: 23, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/empty/snapshots/3-Babel-AST.shot b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/empty/snapshots/3-Babel-AST.shot
new file mode 100644
index 000000000000..43be5f098ab0
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/empty/snapshots/3-Babel-AST.shot
@@ -0,0 +1,40 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSDeclareFunction empty Babel - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    TSDeclareFunction {
+      type: "TSDeclareFunction",
+      async: false,
+      declare: true,
+      expression: false,
+      generator: false,
+      id: Identifier {
+        type: "Identifier",
+        name: "foo",
+
+        range: [17, 20],
+        loc: {
+          start: { column: 17, line: 1 },
+          end: { column: 20, line: 1 },
+        },
+      },
+      params: Array [],
+
+      range: [0, 23],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 23, line: 1 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 24],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/empty/snapshots/4-Babel-Tokens.shot b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/empty/snapshots/4-Babel-Tokens.shot
new file mode 100644
index 000000000000..ec3fc4b9093e
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/empty/snapshots/4-Babel-Tokens.shot
@@ -0,0 +1,66 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSDeclareFunction empty Babel - Tokens 1`] = `
+Array [
+  Identifier {
+    type: "Identifier",
+    value: "declare",
+
+    range: [0, 7],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 7, line: 1 },
+    },
+  },
+  Keyword {
+    type: "Keyword",
+    value: "function",
+
+    range: [8, 16],
+    loc: {
+      start: { column: 8, line: 1 },
+      end: { column: 16, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "foo",
+
+    range: [17, 20],
+    loc: {
+      start: { column: 17, line: 1 },
+      end: { column: 20, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "(",
+
+    range: [20, 21],
+    loc: {
+      start: { column: 20, line: 1 },
+      end: { column: 21, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ")",
+
+    range: [21, 22],
+    loc: {
+      start: { column: 21, line: 1 },
+      end: { column: 22, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ";",
+
+    range: [22, 23],
+    loc: {
+      start: { column: 22, line: 1 },
+      end: { column: 23, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/empty/snapshots/5-AST-Alignment-AST.shot b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/empty/snapshots/5-AST-Alignment-AST.shot
new file mode 100644
index 000000000000..89f8ab5e3471
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/empty/snapshots/5-AST-Alignment-AST.shot
@@ -0,0 +1,6 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSDeclareFunction empty AST Alignment - AST 1`] = `
+"Snapshot Diff:
+Compared values have no visual difference."
+`;
diff --git a/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/empty/snapshots/6-AST-Alignment-Tokens.shot b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/empty/snapshots/6-AST-Alignment-Tokens.shot
new file mode 100644
index 000000000000..e5a96e857c6e
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/empty/snapshots/6-AST-Alignment-Tokens.shot
@@ -0,0 +1,6 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSDeclareFunction empty AST Alignment - Token 1`] = `
+"Snapshot Diff:
+Compared values have no visual difference."
+`;
diff --git a/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/generator/fixture.ts b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/generator/fixture.ts
new file mode 100644
index 000000000000..55243eab2f56
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/generator/fixture.ts
@@ -0,0 +1 @@
+declare function* foo();
diff --git a/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/generator/snapshots/1-TSESTree-AST.shot b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/generator/snapshots/1-TSESTree-AST.shot
new file mode 100644
index 000000000000..ed8b53057929
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/generator/snapshots/1-TSESTree-AST.shot
@@ -0,0 +1,40 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSDeclareFunction generator TSESTree - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    TSDeclareFunction {
+      type: "TSDeclareFunction",
+      async: false,
+      declare: true,
+      expression: false,
+      generator: true,
+      id: Identifier {
+        type: "Identifier",
+        name: "foo",
+
+        range: [18, 21],
+        loc: {
+          start: { column: 18, line: 1 },
+          end: { column: 21, line: 1 },
+        },
+      },
+      params: Array [],
+
+      range: [0, 24],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 24, line: 1 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 25],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/generator/snapshots/2-TSESTree-Tokens.shot b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/generator/snapshots/2-TSESTree-Tokens.shot
new file mode 100644
index 000000000000..a01528659408
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/generator/snapshots/2-TSESTree-Tokens.shot
@@ -0,0 +1,76 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSDeclareFunction generator TSESTree - Tokens 1`] = `
+Array [
+  Identifier {
+    type: "Identifier",
+    value: "declare",
+
+    range: [0, 7],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 7, line: 1 },
+    },
+  },
+  Keyword {
+    type: "Keyword",
+    value: "function",
+
+    range: [8, 16],
+    loc: {
+      start: { column: 8, line: 1 },
+      end: { column: 16, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "*",
+
+    range: [16, 17],
+    loc: {
+      start: { column: 16, line: 1 },
+      end: { column: 17, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "foo",
+
+    range: [18, 21],
+    loc: {
+      start: { column: 18, line: 1 },
+      end: { column: 21, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "(",
+
+    range: [21, 22],
+    loc: {
+      start: { column: 21, line: 1 },
+      end: { column: 22, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ")",
+
+    range: [22, 23],
+    loc: {
+      start: { column: 22, line: 1 },
+      end: { column: 23, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ";",
+
+    range: [23, 24],
+    loc: {
+      start: { column: 23, line: 1 },
+      end: { column: 24, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/generator/snapshots/3-Babel-AST.shot b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/generator/snapshots/3-Babel-AST.shot
new file mode 100644
index 000000000000..3da973bf9f5f
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/generator/snapshots/3-Babel-AST.shot
@@ -0,0 +1,40 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSDeclareFunction generator Babel - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    TSDeclareFunction {
+      type: "TSDeclareFunction",
+      async: false,
+      declare: true,
+      expression: false,
+      generator: true,
+      id: Identifier {
+        type: "Identifier",
+        name: "foo",
+
+        range: [18, 21],
+        loc: {
+          start: { column: 18, line: 1 },
+          end: { column: 21, line: 1 },
+        },
+      },
+      params: Array [],
+
+      range: [0, 24],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 24, line: 1 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 25],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/generator/snapshots/4-Babel-Tokens.shot b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/generator/snapshots/4-Babel-Tokens.shot
new file mode 100644
index 000000000000..58082427903c
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/generator/snapshots/4-Babel-Tokens.shot
@@ -0,0 +1,76 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSDeclareFunction generator Babel - Tokens 1`] = `
+Array [
+  Identifier {
+    type: "Identifier",
+    value: "declare",
+
+    range: [0, 7],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 7, line: 1 },
+    },
+  },
+  Keyword {
+    type: "Keyword",
+    value: "function",
+
+    range: [8, 16],
+    loc: {
+      start: { column: 8, line: 1 },
+      end: { column: 16, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "*",
+
+    range: [16, 17],
+    loc: {
+      start: { column: 16, line: 1 },
+      end: { column: 17, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "foo",
+
+    range: [18, 21],
+    loc: {
+      start: { column: 18, line: 1 },
+      end: { column: 21, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "(",
+
+    range: [21, 22],
+    loc: {
+      start: { column: 21, line: 1 },
+      end: { column: 22, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ")",
+
+    range: [22, 23],
+    loc: {
+      start: { column: 22, line: 1 },
+      end: { column: 23, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ";",
+
+    range: [23, 24],
+    loc: {
+      start: { column: 23, line: 1 },
+      end: { column: 24, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/generator/snapshots/5-AST-Alignment-AST.shot b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/generator/snapshots/5-AST-Alignment-AST.shot
new file mode 100644
index 000000000000..e5478271a49b
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/generator/snapshots/5-AST-Alignment-AST.shot
@@ -0,0 +1,6 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSDeclareFunction generator AST Alignment - AST 1`] = `
+"Snapshot Diff:
+Compared values have no visual difference."
+`;
diff --git a/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/generator/snapshots/6-AST-Alignment-Tokens.shot b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/generator/snapshots/6-AST-Alignment-Tokens.shot
new file mode 100644
index 000000000000..0c5870a8a61e
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/generator/snapshots/6-AST-Alignment-Tokens.shot
@@ -0,0 +1,6 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSDeclareFunction generator AST Alignment - Token 1`] = `
+"Snapshot Diff:
+Compared values have no visual difference."
+`;
diff --git a/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/param-many/fixture.ts b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/param-many/fixture.ts
new file mode 100644
index 000000000000..3f5ccd7a7bf6
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/param-many/fixture.ts
@@ -0,0 +1 @@
+declare function foo(a, b, c);
diff --git a/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/param-many/snapshots/1-TSESTree-AST.shot b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/param-many/snapshots/1-TSESTree-AST.shot
new file mode 100644
index 000000000000..a7f8479f43a4
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/param-many/snapshots/1-TSESTree-AST.shot
@@ -0,0 +1,71 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSDeclareFunction param-many TSESTree - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    TSDeclareFunction {
+      type: "TSDeclareFunction",
+      async: false,
+      declare: true,
+      expression: false,
+      generator: false,
+      id: Identifier {
+        type: "Identifier",
+        name: "foo",
+
+        range: [17, 20],
+        loc: {
+          start: { column: 17, line: 1 },
+          end: { column: 20, line: 1 },
+        },
+      },
+      params: Array [
+        Identifier {
+          type: "Identifier",
+          name: "a",
+
+          range: [21, 22],
+          loc: {
+            start: { column: 21, line: 1 },
+            end: { column: 22, line: 1 },
+          },
+        },
+        Identifier {
+          type: "Identifier",
+          name: "b",
+
+          range: [24, 25],
+          loc: {
+            start: { column: 24, line: 1 },
+            end: { column: 25, line: 1 },
+          },
+        },
+        Identifier {
+          type: "Identifier",
+          name: "c",
+
+          range: [27, 28],
+          loc: {
+            start: { column: 27, line: 1 },
+            end: { column: 28, line: 1 },
+          },
+        },
+      ],
+
+      range: [0, 30],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 30, line: 1 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 31],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/param-many/snapshots/2-TSESTree-Tokens.shot b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/param-many/snapshots/2-TSESTree-Tokens.shot
new file mode 100644
index 000000000000..f6aa7066f1a7
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/param-many/snapshots/2-TSESTree-Tokens.shot
@@ -0,0 +1,116 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSDeclareFunction param-many TSESTree - Tokens 1`] = `
+Array [
+  Identifier {
+    type: "Identifier",
+    value: "declare",
+
+    range: [0, 7],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 7, line: 1 },
+    },
+  },
+  Keyword {
+    type: "Keyword",
+    value: "function",
+
+    range: [8, 16],
+    loc: {
+      start: { column: 8, line: 1 },
+      end: { column: 16, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "foo",
+
+    range: [17, 20],
+    loc: {
+      start: { column: 17, line: 1 },
+      end: { column: 20, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "(",
+
+    range: [20, 21],
+    loc: {
+      start: { column: 20, line: 1 },
+      end: { column: 21, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "a",
+
+    range: [21, 22],
+    loc: {
+      start: { column: 21, line: 1 },
+      end: { column: 22, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ",",
+
+    range: [22, 23],
+    loc: {
+      start: { column: 22, line: 1 },
+      end: { column: 23, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "b",
+
+    range: [24, 25],
+    loc: {
+      start: { column: 24, line: 1 },
+      end: { column: 25, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ",",
+
+    range: [25, 26],
+    loc: {
+      start: { column: 25, line: 1 },
+      end: { column: 26, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "c",
+
+    range: [27, 28],
+    loc: {
+      start: { column: 27, line: 1 },
+      end: { column: 28, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ")",
+
+    range: [28, 29],
+    loc: {
+      start: { column: 28, line: 1 },
+      end: { column: 29, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ";",
+
+    range: [29, 30],
+    loc: {
+      start: { column: 29, line: 1 },
+      end: { column: 30, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/param-many/snapshots/3-Babel-AST.shot b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/param-many/snapshots/3-Babel-AST.shot
new file mode 100644
index 000000000000..d1e098a0e89d
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/param-many/snapshots/3-Babel-AST.shot
@@ -0,0 +1,71 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSDeclareFunction param-many Babel - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    TSDeclareFunction {
+      type: "TSDeclareFunction",
+      async: false,
+      declare: true,
+      expression: false,
+      generator: false,
+      id: Identifier {
+        type: "Identifier",
+        name: "foo",
+
+        range: [17, 20],
+        loc: {
+          start: { column: 17, line: 1 },
+          end: { column: 20, line: 1 },
+        },
+      },
+      params: Array [
+        Identifier {
+          type: "Identifier",
+          name: "a",
+
+          range: [21, 22],
+          loc: {
+            start: { column: 21, line: 1 },
+            end: { column: 22, line: 1 },
+          },
+        },
+        Identifier {
+          type: "Identifier",
+          name: "b",
+
+          range: [24, 25],
+          loc: {
+            start: { column: 24, line: 1 },
+            end: { column: 25, line: 1 },
+          },
+        },
+        Identifier {
+          type: "Identifier",
+          name: "c",
+
+          range: [27, 28],
+          loc: {
+            start: { column: 27, line: 1 },
+            end: { column: 28, line: 1 },
+          },
+        },
+      ],
+
+      range: [0, 30],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 30, line: 1 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 31],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/param-many/snapshots/4-Babel-Tokens.shot b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/param-many/snapshots/4-Babel-Tokens.shot
new file mode 100644
index 000000000000..c27b9fa0a5ec
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/param-many/snapshots/4-Babel-Tokens.shot
@@ -0,0 +1,116 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSDeclareFunction param-many Babel - Tokens 1`] = `
+Array [
+  Identifier {
+    type: "Identifier",
+    value: "declare",
+
+    range: [0, 7],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 7, line: 1 },
+    },
+  },
+  Keyword {
+    type: "Keyword",
+    value: "function",
+
+    range: [8, 16],
+    loc: {
+      start: { column: 8, line: 1 },
+      end: { column: 16, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "foo",
+
+    range: [17, 20],
+    loc: {
+      start: { column: 17, line: 1 },
+      end: { column: 20, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "(",
+
+    range: [20, 21],
+    loc: {
+      start: { column: 20, line: 1 },
+      end: { column: 21, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "a",
+
+    range: [21, 22],
+    loc: {
+      start: { column: 21, line: 1 },
+      end: { column: 22, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ",",
+
+    range: [22, 23],
+    loc: {
+      start: { column: 22, line: 1 },
+      end: { column: 23, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "b",
+
+    range: [24, 25],
+    loc: {
+      start: { column: 24, line: 1 },
+      end: { column: 25, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ",",
+
+    range: [25, 26],
+    loc: {
+      start: { column: 25, line: 1 },
+      end: { column: 26, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "c",
+
+    range: [27, 28],
+    loc: {
+      start: { column: 27, line: 1 },
+      end: { column: 28, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ")",
+
+    range: [28, 29],
+    loc: {
+      start: { column: 28, line: 1 },
+      end: { column: 29, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ";",
+
+    range: [29, 30],
+    loc: {
+      start: { column: 29, line: 1 },
+      end: { column: 30, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/param-many/snapshots/5-AST-Alignment-AST.shot b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/param-many/snapshots/5-AST-Alignment-AST.shot
new file mode 100644
index 000000000000..cfed52f085e8
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/param-many/snapshots/5-AST-Alignment-AST.shot
@@ -0,0 +1,6 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSDeclareFunction param-many AST Alignment - AST 1`] = `
+"Snapshot Diff:
+Compared values have no visual difference."
+`;
diff --git a/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/param-many/snapshots/6-AST-Alignment-Tokens.shot b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/param-many/snapshots/6-AST-Alignment-Tokens.shot
new file mode 100644
index 000000000000..d41363d11c2c
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/param-many/snapshots/6-AST-Alignment-Tokens.shot
@@ -0,0 +1,6 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSDeclareFunction param-many AST Alignment - Token 1`] = `
+"Snapshot Diff:
+Compared values have no visual difference."
+`;
diff --git a/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/param-one/fixture.ts b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/param-one/fixture.ts
new file mode 100644
index 000000000000..1e929f63edd2
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/param-one/fixture.ts
@@ -0,0 +1 @@
+declare function foo(a);
diff --git a/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/param-one/snapshots/1-TSESTree-AST.shot b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/param-one/snapshots/1-TSESTree-AST.shot
new file mode 100644
index 000000000000..1f21a6f71f80
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/param-one/snapshots/1-TSESTree-AST.shot
@@ -0,0 +1,51 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSDeclareFunction param-one TSESTree - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    TSDeclareFunction {
+      type: "TSDeclareFunction",
+      async: false,
+      declare: true,
+      expression: false,
+      generator: false,
+      id: Identifier {
+        type: "Identifier",
+        name: "foo",
+
+        range: [17, 20],
+        loc: {
+          start: { column: 17, line: 1 },
+          end: { column: 20, line: 1 },
+        },
+      },
+      params: Array [
+        Identifier {
+          type: "Identifier",
+          name: "a",
+
+          range: [21, 22],
+          loc: {
+            start: { column: 21, line: 1 },
+            end: { column: 22, line: 1 },
+          },
+        },
+      ],
+
+      range: [0, 24],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 24, line: 1 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 25],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/param-one/snapshots/2-TSESTree-Tokens.shot b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/param-one/snapshots/2-TSESTree-Tokens.shot
new file mode 100644
index 000000000000..d8412c942126
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/param-one/snapshots/2-TSESTree-Tokens.shot
@@ -0,0 +1,76 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSDeclareFunction param-one TSESTree - Tokens 1`] = `
+Array [
+  Identifier {
+    type: "Identifier",
+    value: "declare",
+
+    range: [0, 7],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 7, line: 1 },
+    },
+  },
+  Keyword {
+    type: "Keyword",
+    value: "function",
+
+    range: [8, 16],
+    loc: {
+      start: { column: 8, line: 1 },
+      end: { column: 16, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "foo",
+
+    range: [17, 20],
+    loc: {
+      start: { column: 17, line: 1 },
+      end: { column: 20, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "(",
+
+    range: [20, 21],
+    loc: {
+      start: { column: 20, line: 1 },
+      end: { column: 21, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "a",
+
+    range: [21, 22],
+    loc: {
+      start: { column: 21, line: 1 },
+      end: { column: 22, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ")",
+
+    range: [22, 23],
+    loc: {
+      start: { column: 22, line: 1 },
+      end: { column: 23, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ";",
+
+    range: [23, 24],
+    loc: {
+      start: { column: 23, line: 1 },
+      end: { column: 24, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/param-one/snapshots/3-Babel-AST.shot b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/param-one/snapshots/3-Babel-AST.shot
new file mode 100644
index 000000000000..abf7337612c7
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/param-one/snapshots/3-Babel-AST.shot
@@ -0,0 +1,51 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSDeclareFunction param-one Babel - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    TSDeclareFunction {
+      type: "TSDeclareFunction",
+      async: false,
+      declare: true,
+      expression: false,
+      generator: false,
+      id: Identifier {
+        type: "Identifier",
+        name: "foo",
+
+        range: [17, 20],
+        loc: {
+          start: { column: 17, line: 1 },
+          end: { column: 20, line: 1 },
+        },
+      },
+      params: Array [
+        Identifier {
+          type: "Identifier",
+          name: "a",
+
+          range: [21, 22],
+          loc: {
+            start: { column: 21, line: 1 },
+            end: { column: 22, line: 1 },
+          },
+        },
+      ],
+
+      range: [0, 24],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 24, line: 1 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 25],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/param-one/snapshots/4-Babel-Tokens.shot b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/param-one/snapshots/4-Babel-Tokens.shot
new file mode 100644
index 000000000000..9dba1e7717cd
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/param-one/snapshots/4-Babel-Tokens.shot
@@ -0,0 +1,76 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSDeclareFunction param-one Babel - Tokens 1`] = `
+Array [
+  Identifier {
+    type: "Identifier",
+    value: "declare",
+
+    range: [0, 7],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 7, line: 1 },
+    },
+  },
+  Keyword {
+    type: "Keyword",
+    value: "function",
+
+    range: [8, 16],
+    loc: {
+      start: { column: 8, line: 1 },
+      end: { column: 16, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "foo",
+
+    range: [17, 20],
+    loc: {
+      start: { column: 17, line: 1 },
+      end: { column: 20, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "(",
+
+    range: [20, 21],
+    loc: {
+      start: { column: 20, line: 1 },
+      end: { column: 21, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "a",
+
+    range: [21, 22],
+    loc: {
+      start: { column: 21, line: 1 },
+      end: { column: 22, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ")",
+
+    range: [22, 23],
+    loc: {
+      start: { column: 22, line: 1 },
+      end: { column: 23, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ";",
+
+    range: [23, 24],
+    loc: {
+      start: { column: 23, line: 1 },
+      end: { column: 24, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/param-one/snapshots/5-AST-Alignment-AST.shot b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/param-one/snapshots/5-AST-Alignment-AST.shot
new file mode 100644
index 000000000000..81f8c45d6564
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/param-one/snapshots/5-AST-Alignment-AST.shot
@@ -0,0 +1,6 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSDeclareFunction param-one AST Alignment - AST 1`] = `
+"Snapshot Diff:
+Compared values have no visual difference."
+`;
diff --git a/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/param-one/snapshots/6-AST-Alignment-Tokens.shot b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/param-one/snapshots/6-AST-Alignment-Tokens.shot
new file mode 100644
index 000000000000..ab3a33eb7f9b
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/param-one/snapshots/6-AST-Alignment-Tokens.shot
@@ -0,0 +1,6 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSDeclareFunction param-one AST Alignment - Token 1`] = `
+"Snapshot Diff:
+Compared values have no visual difference."
+`;
diff --git a/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/returnType/fixture.ts b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/returnType/fixture.ts
new file mode 100644
index 000000000000..7ab5bf149376
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/returnType/fixture.ts
@@ -0,0 +1 @@
+declare function foo(): void;
diff --git a/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/returnType/snapshots/1-TSESTree-AST.shot b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/returnType/snapshots/1-TSESTree-AST.shot
new file mode 100644
index 000000000000..45e65dbe80a1
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/returnType/snapshots/1-TSESTree-AST.shot
@@ -0,0 +1,58 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSDeclareFunction returnType TSESTree - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    TSDeclareFunction {
+      type: "TSDeclareFunction",
+      async: false,
+      declare: true,
+      expression: false,
+      generator: false,
+      id: Identifier {
+        type: "Identifier",
+        name: "foo",
+
+        range: [17, 20],
+        loc: {
+          start: { column: 17, line: 1 },
+          end: { column: 20, line: 1 },
+        },
+      },
+      params: Array [],
+      returnType: TSTypeAnnotation {
+        type: "TSTypeAnnotation",
+        typeAnnotation: TSVoidKeyword {
+          type: "TSVoidKeyword",
+
+          range: [24, 28],
+          loc: {
+            start: { column: 24, line: 1 },
+            end: { column: 28, line: 1 },
+          },
+        },
+
+        range: [22, 28],
+        loc: {
+          start: { column: 22, line: 1 },
+          end: { column: 28, line: 1 },
+        },
+      },
+
+      range: [0, 29],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 29, line: 1 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 30],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/returnType/snapshots/2-TSESTree-Tokens.shot b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/returnType/snapshots/2-TSESTree-Tokens.shot
new file mode 100644
index 000000000000..f06fda6f01ee
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/returnType/snapshots/2-TSESTree-Tokens.shot
@@ -0,0 +1,86 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSDeclareFunction returnType TSESTree - Tokens 1`] = `
+Array [
+  Identifier {
+    type: "Identifier",
+    value: "declare",
+
+    range: [0, 7],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 7, line: 1 },
+    },
+  },
+  Keyword {
+    type: "Keyword",
+    value: "function",
+
+    range: [8, 16],
+    loc: {
+      start: { column: 8, line: 1 },
+      end: { column: 16, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "foo",
+
+    range: [17, 20],
+    loc: {
+      start: { column: 17, line: 1 },
+      end: { column: 20, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "(",
+
+    range: [20, 21],
+    loc: {
+      start: { column: 20, line: 1 },
+      end: { column: 21, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ")",
+
+    range: [21, 22],
+    loc: {
+      start: { column: 21, line: 1 },
+      end: { column: 22, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ":",
+
+    range: [22, 23],
+    loc: {
+      start: { column: 22, line: 1 },
+      end: { column: 23, line: 1 },
+    },
+  },
+  Keyword {
+    type: "Keyword",
+    value: "void",
+
+    range: [24, 28],
+    loc: {
+      start: { column: 24, line: 1 },
+      end: { column: 28, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ";",
+
+    range: [28, 29],
+    loc: {
+      start: { column: 28, line: 1 },
+      end: { column: 29, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/returnType/snapshots/3-Babel-AST.shot b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/returnType/snapshots/3-Babel-AST.shot
new file mode 100644
index 000000000000..1ccc35aaadb4
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/returnType/snapshots/3-Babel-AST.shot
@@ -0,0 +1,58 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSDeclareFunction returnType Babel - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    TSDeclareFunction {
+      type: "TSDeclareFunction",
+      async: false,
+      declare: true,
+      expression: false,
+      generator: false,
+      id: Identifier {
+        type: "Identifier",
+        name: "foo",
+
+        range: [17, 20],
+        loc: {
+          start: { column: 17, line: 1 },
+          end: { column: 20, line: 1 },
+        },
+      },
+      params: Array [],
+      returnType: TSTypeAnnotation {
+        type: "TSTypeAnnotation",
+        typeAnnotation: TSVoidKeyword {
+          type: "TSVoidKeyword",
+
+          range: [24, 28],
+          loc: {
+            start: { column: 24, line: 1 },
+            end: { column: 28, line: 1 },
+          },
+        },
+
+        range: [22, 28],
+        loc: {
+          start: { column: 22, line: 1 },
+          end: { column: 28, line: 1 },
+        },
+      },
+
+      range: [0, 29],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 29, line: 1 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 30],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/returnType/snapshots/4-Babel-Tokens.shot b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/returnType/snapshots/4-Babel-Tokens.shot
new file mode 100644
index 000000000000..703e02000f58
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/returnType/snapshots/4-Babel-Tokens.shot
@@ -0,0 +1,86 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSDeclareFunction returnType Babel - Tokens 1`] = `
+Array [
+  Identifier {
+    type: "Identifier",
+    value: "declare",
+
+    range: [0, 7],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 7, line: 1 },
+    },
+  },
+  Keyword {
+    type: "Keyword",
+    value: "function",
+
+    range: [8, 16],
+    loc: {
+      start: { column: 8, line: 1 },
+      end: { column: 16, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "foo",
+
+    range: [17, 20],
+    loc: {
+      start: { column: 17, line: 1 },
+      end: { column: 20, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "(",
+
+    range: [20, 21],
+    loc: {
+      start: { column: 20, line: 1 },
+      end: { column: 21, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ")",
+
+    range: [21, 22],
+    loc: {
+      start: { column: 21, line: 1 },
+      end: { column: 22, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ":",
+
+    range: [22, 23],
+    loc: {
+      start: { column: 22, line: 1 },
+      end: { column: 23, line: 1 },
+    },
+  },
+  Keyword {
+    type: "Keyword",
+    value: "void",
+
+    range: [24, 28],
+    loc: {
+      start: { column: 24, line: 1 },
+      end: { column: 28, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ";",
+
+    range: [28, 29],
+    loc: {
+      start: { column: 28, line: 1 },
+      end: { column: 29, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/returnType/snapshots/5-AST-Alignment-AST.shot b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/returnType/snapshots/5-AST-Alignment-AST.shot
new file mode 100644
index 000000000000..bddda38b36f0
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/returnType/snapshots/5-AST-Alignment-AST.shot
@@ -0,0 +1,6 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSDeclareFunction returnType AST Alignment - AST 1`] = `
+"Snapshot Diff:
+Compared values have no visual difference."
+`;
diff --git a/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/returnType/snapshots/6-AST-Alignment-Tokens.shot b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/returnType/snapshots/6-AST-Alignment-Tokens.shot
new file mode 100644
index 000000000000..994903ee6092
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/returnType/snapshots/6-AST-Alignment-Tokens.shot
@@ -0,0 +1,6 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSDeclareFunction returnType AST Alignment - Token 1`] = `
+"Snapshot Diff:
+Compared values have no visual difference."
+`;
diff --git a/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/type-param-many/fixture.ts b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/type-param-many/fixture.ts
new file mode 100644
index 000000000000..4ab67258323e
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/type-param-many/fixture.ts
@@ -0,0 +1 @@
+declare function foo<T, U, V>();
diff --git a/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/type-param-many/snapshots/1-TSESTree-AST.shot b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/type-param-many/snapshots/1-TSESTree-AST.shot
new file mode 100644
index 000000000000..aefd6e905e23
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/type-param-many/snapshots/1-TSESTree-AST.shot
@@ -0,0 +1,114 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSDeclareFunction type-param-many TSESTree - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    TSDeclareFunction {
+      type: "TSDeclareFunction",
+      async: false,
+      declare: true,
+      expression: false,
+      generator: false,
+      id: Identifier {
+        type: "Identifier",
+        name: "foo",
+
+        range: [17, 20],
+        loc: {
+          start: { column: 17, line: 1 },
+          end: { column: 20, line: 1 },
+        },
+      },
+      params: Array [],
+      typeParameters: TSTypeParameterDeclaration {
+        type: "TSTypeParameterDeclaration",
+        params: Array [
+          TSTypeParameter {
+            type: "TSTypeParameter",
+            in: false,
+            name: Identifier {
+              type: "Identifier",
+              name: "T",
+
+              range: [21, 22],
+              loc: {
+                start: { column: 21, line: 1 },
+                end: { column: 22, line: 1 },
+              },
+            },
+            out: false,
+
+            range: [21, 22],
+            loc: {
+              start: { column: 21, line: 1 },
+              end: { column: 22, line: 1 },
+            },
+          },
+          TSTypeParameter {
+            type: "TSTypeParameter",
+            in: false,
+            name: Identifier {
+              type: "Identifier",
+              name: "U",
+
+              range: [24, 25],
+              loc: {
+                start: { column: 24, line: 1 },
+                end: { column: 25, line: 1 },
+              },
+            },
+            out: false,
+
+            range: [24, 25],
+            loc: {
+              start: { column: 24, line: 1 },
+              end: { column: 25, line: 1 },
+            },
+          },
+          TSTypeParameter {
+            type: "TSTypeParameter",
+            in: false,
+            name: Identifier {
+              type: "Identifier",
+              name: "V",
+
+              range: [27, 28],
+              loc: {
+                start: { column: 27, line: 1 },
+                end: { column: 28, line: 1 },
+              },
+            },
+            out: false,
+
+            range: [27, 28],
+            loc: {
+              start: { column: 27, line: 1 },
+              end: { column: 28, line: 1 },
+            },
+          },
+        ],
+
+        range: [20, 29],
+        loc: {
+          start: { column: 20, line: 1 },
+          end: { column: 29, line: 1 },
+        },
+      },
+
+      range: [0, 32],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 32, line: 1 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 33],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/type-param-many/snapshots/2-TSESTree-Tokens.shot b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/type-param-many/snapshots/2-TSESTree-Tokens.shot
new file mode 100644
index 000000000000..92b21a76dcf5
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/type-param-many/snapshots/2-TSESTree-Tokens.shot
@@ -0,0 +1,136 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSDeclareFunction type-param-many TSESTree - Tokens 1`] = `
+Array [
+  Identifier {
+    type: "Identifier",
+    value: "declare",
+
+    range: [0, 7],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 7, line: 1 },
+    },
+  },
+  Keyword {
+    type: "Keyword",
+    value: "function",
+
+    range: [8, 16],
+    loc: {
+      start: { column: 8, line: 1 },
+      end: { column: 16, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "foo",
+
+    range: [17, 20],
+    loc: {
+      start: { column: 17, line: 1 },
+      end: { column: 20, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "<",
+
+    range: [20, 21],
+    loc: {
+      start: { column: 20, line: 1 },
+      end: { column: 21, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "T",
+
+    range: [21, 22],
+    loc: {
+      start: { column: 21, line: 1 },
+      end: { column: 22, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ",",
+
+    range: [22, 23],
+    loc: {
+      start: { column: 22, line: 1 },
+      end: { column: 23, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "U",
+
+    range: [24, 25],
+    loc: {
+      start: { column: 24, line: 1 },
+      end: { column: 25, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ",",
+
+    range: [25, 26],
+    loc: {
+      start: { column: 25, line: 1 },
+      end: { column: 26, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "V",
+
+    range: [27, 28],
+    loc: {
+      start: { column: 27, line: 1 },
+      end: { column: 28, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ">",
+
+    range: [28, 29],
+    loc: {
+      start: { column: 28, line: 1 },
+      end: { column: 29, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "(",
+
+    range: [29, 30],
+    loc: {
+      start: { column: 29, line: 1 },
+      end: { column: 30, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ")",
+
+    range: [30, 31],
+    loc: {
+      start: { column: 30, line: 1 },
+      end: { column: 31, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ";",
+
+    range: [31, 32],
+    loc: {
+      start: { column: 31, line: 1 },
+      end: { column: 32, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/type-param-many/snapshots/3-Babel-AST.shot b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/type-param-many/snapshots/3-Babel-AST.shot
new file mode 100644
index 000000000000..76dc2ebf1f56
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/type-param-many/snapshots/3-Babel-AST.shot
@@ -0,0 +1,81 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSDeclareFunction type-param-many Babel - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    TSDeclareFunction {
+      type: "TSDeclareFunction",
+      async: false,
+      declare: true,
+      expression: false,
+      generator: false,
+      id: Identifier {
+        type: "Identifier",
+        name: "foo",
+
+        range: [17, 20],
+        loc: {
+          start: { column: 17, line: 1 },
+          end: { column: 20, line: 1 },
+        },
+      },
+      params: Array [],
+      typeParameters: TSTypeParameterDeclaration {
+        type: "TSTypeParameterDeclaration",
+        params: Array [
+          TSTypeParameter {
+            type: "TSTypeParameter",
+            name: "T",
+
+            range: [21, 22],
+            loc: {
+              start: { column: 21, line: 1 },
+              end: { column: 22, line: 1 },
+            },
+          },
+          TSTypeParameter {
+            type: "TSTypeParameter",
+            name: "U",
+
+            range: [24, 25],
+            loc: {
+              start: { column: 24, line: 1 },
+              end: { column: 25, line: 1 },
+            },
+          },
+          TSTypeParameter {
+            type: "TSTypeParameter",
+            name: "V",
+
+            range: [27, 28],
+            loc: {
+              start: { column: 27, line: 1 },
+              end: { column: 28, line: 1 },
+            },
+          },
+        ],
+
+        range: [20, 29],
+        loc: {
+          start: { column: 20, line: 1 },
+          end: { column: 29, line: 1 },
+        },
+      },
+
+      range: [0, 32],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 32, line: 1 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 33],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/type-param-many/snapshots/4-Babel-Tokens.shot b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/type-param-many/snapshots/4-Babel-Tokens.shot
new file mode 100644
index 000000000000..6aaaa58051c6
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/type-param-many/snapshots/4-Babel-Tokens.shot
@@ -0,0 +1,136 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSDeclareFunction type-param-many Babel - Tokens 1`] = `
+Array [
+  Identifier {
+    type: "Identifier",
+    value: "declare",
+
+    range: [0, 7],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 7, line: 1 },
+    },
+  },
+  Keyword {
+    type: "Keyword",
+    value: "function",
+
+    range: [8, 16],
+    loc: {
+      start: { column: 8, line: 1 },
+      end: { column: 16, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "foo",
+
+    range: [17, 20],
+    loc: {
+      start: { column: 17, line: 1 },
+      end: { column: 20, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "<",
+
+    range: [20, 21],
+    loc: {
+      start: { column: 20, line: 1 },
+      end: { column: 21, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "T",
+
+    range: [21, 22],
+    loc: {
+      start: { column: 21, line: 1 },
+      end: { column: 22, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ",",
+
+    range: [22, 23],
+    loc: {
+      start: { column: 22, line: 1 },
+      end: { column: 23, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "U",
+
+    range: [24, 25],
+    loc: {
+      start: { column: 24, line: 1 },
+      end: { column: 25, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ",",
+
+    range: [25, 26],
+    loc: {
+      start: { column: 25, line: 1 },
+      end: { column: 26, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "V",
+
+    range: [27, 28],
+    loc: {
+      start: { column: 27, line: 1 },
+      end: { column: 28, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ">",
+
+    range: [28, 29],
+    loc: {
+      start: { column: 28, line: 1 },
+      end: { column: 29, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "(",
+
+    range: [29, 30],
+    loc: {
+      start: { column: 29, line: 1 },
+      end: { column: 30, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ")",
+
+    range: [30, 31],
+    loc: {
+      start: { column: 30, line: 1 },
+      end: { column: 31, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ";",
+
+    range: [31, 32],
+    loc: {
+      start: { column: 31, line: 1 },
+      end: { column: 32, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/type-param-many/snapshots/5-AST-Alignment-AST.shot b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/type-param-many/snapshots/5-AST-Alignment-AST.shot
new file mode 100644
index 000000000000..5c07aedab59c
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/type-param-many/snapshots/5-AST-Alignment-AST.shot
@@ -0,0 +1,121 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSDeclareFunction type-param-many AST Alignment - AST 1`] = `
+"Snapshot Diff:
+- TSESTree
++ Babel
+
+  Program {
+    type: 'Program',
+    body: Array [
+      TSDeclareFunction {
+        type: 'TSDeclareFunction',
+        async: false,
+        declare: true,
+        expression: false,
+        generator: false,
+        id: Identifier {
+          type: 'Identifier',
+          name: 'foo',
+
+          range: [17, 20],
+          loc: {
+            start: { column: 17, line: 1 },
+            end: { column: 20, line: 1 },
+          },
+        },
+        params: Array [],
+        typeParameters: TSTypeParameterDeclaration {
+          type: 'TSTypeParameterDeclaration',
+          params: Array [
+            TSTypeParameter {
+              type: 'TSTypeParameter',
+-             in: false,
+-             name: Identifier {
+-               type: 'Identifier',
+-               name: 'T',
+-
+-               range: [21, 22],
+-               loc: {
+-                 start: { column: 21, line: 1 },
+-                 end: { column: 22, line: 1 },
+-               },
+-             },
+-             out: false,
++             name: 'T',
+
+              range: [21, 22],
+              loc: {
+                start: { column: 21, line: 1 },
+                end: { column: 22, line: 1 },
+              },
+            },
+            TSTypeParameter {
+              type: 'TSTypeParameter',
+-             in: false,
+-             name: Identifier {
+-               type: 'Identifier',
+-               name: 'U',
+-
+-               range: [24, 25],
+-               loc: {
+-                 start: { column: 24, line: 1 },
+-                 end: { column: 25, line: 1 },
+-               },
+-             },
+-             out: false,
++             name: 'U',
+
+              range: [24, 25],
+              loc: {
+                start: { column: 24, line: 1 },
+                end: { column: 25, line: 1 },
+              },
+            },
+            TSTypeParameter {
+              type: 'TSTypeParameter',
+-             in: false,
+-             name: Identifier {
+-               type: 'Identifier',
+-               name: 'V',
+-
+-               range: [27, 28],
+-               loc: {
+-                 start: { column: 27, line: 1 },
+-                 end: { column: 28, line: 1 },
+-               },
+-             },
+-             out: false,
++             name: 'V',
+
+              range: [27, 28],
+              loc: {
+                start: { column: 27, line: 1 },
+                end: { column: 28, line: 1 },
+              },
+            },
+          ],
+
+          range: [20, 29],
+          loc: {
+            start: { column: 20, line: 1 },
+            end: { column: 29, line: 1 },
+          },
+        },
+
+        range: [0, 32],
+        loc: {
+          start: { column: 0, line: 1 },
+          end: { column: 32, line: 1 },
+        },
+      },
+    ],
+    sourceType: 'script',
+
+    range: [0, 33],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 0, line: 2 },
+    },
+  }"
+`;
diff --git a/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/type-param-many/snapshots/6-AST-Alignment-Tokens.shot b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/type-param-many/snapshots/6-AST-Alignment-Tokens.shot
new file mode 100644
index 000000000000..cae8ddcdbee9
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/type-param-many/snapshots/6-AST-Alignment-Tokens.shot
@@ -0,0 +1,6 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSDeclareFunction type-param-many AST Alignment - Token 1`] = `
+"Snapshot Diff:
+Compared values have no visual difference."
+`;
diff --git a/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/type-param-one/fixture.ts b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/type-param-one/fixture.ts
new file mode 100644
index 000000000000..3f66cd9c4604
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/type-param-one/fixture.ts
@@ -0,0 +1 @@
+declare function foo<T>();
diff --git a/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/type-param-one/snapshots/1-TSESTree-AST.shot b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/type-param-one/snapshots/1-TSESTree-AST.shot
new file mode 100644
index 000000000000..4767a93811ca
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/type-param-one/snapshots/1-TSESTree-AST.shot
@@ -0,0 +1,72 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSDeclareFunction type-param-one TSESTree - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    TSDeclareFunction {
+      type: "TSDeclareFunction",
+      async: false,
+      declare: true,
+      expression: false,
+      generator: false,
+      id: Identifier {
+        type: "Identifier",
+        name: "foo",
+
+        range: [17, 20],
+        loc: {
+          start: { column: 17, line: 1 },
+          end: { column: 20, line: 1 },
+        },
+      },
+      params: Array [],
+      typeParameters: TSTypeParameterDeclaration {
+        type: "TSTypeParameterDeclaration",
+        params: Array [
+          TSTypeParameter {
+            type: "TSTypeParameter",
+            in: false,
+            name: Identifier {
+              type: "Identifier",
+              name: "T",
+
+              range: [21, 22],
+              loc: {
+                start: { column: 21, line: 1 },
+                end: { column: 22, line: 1 },
+              },
+            },
+            out: false,
+
+            range: [21, 22],
+            loc: {
+              start: { column: 21, line: 1 },
+              end: { column: 22, line: 1 },
+            },
+          },
+        ],
+
+        range: [20, 23],
+        loc: {
+          start: { column: 20, line: 1 },
+          end: { column: 23, line: 1 },
+        },
+      },
+
+      range: [0, 26],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 26, line: 1 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 27],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/type-param-one/snapshots/2-TSESTree-Tokens.shot b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/type-param-one/snapshots/2-TSESTree-Tokens.shot
new file mode 100644
index 000000000000..cf3ce53768e1
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/type-param-one/snapshots/2-TSESTree-Tokens.shot
@@ -0,0 +1,96 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSDeclareFunction type-param-one TSESTree - Tokens 1`] = `
+Array [
+  Identifier {
+    type: "Identifier",
+    value: "declare",
+
+    range: [0, 7],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 7, line: 1 },
+    },
+  },
+  Keyword {
+    type: "Keyword",
+    value: "function",
+
+    range: [8, 16],
+    loc: {
+      start: { column: 8, line: 1 },
+      end: { column: 16, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "foo",
+
+    range: [17, 20],
+    loc: {
+      start: { column: 17, line: 1 },
+      end: { column: 20, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "<",
+
+    range: [20, 21],
+    loc: {
+      start: { column: 20, line: 1 },
+      end: { column: 21, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "T",
+
+    range: [21, 22],
+    loc: {
+      start: { column: 21, line: 1 },
+      end: { column: 22, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ">",
+
+    range: [22, 23],
+    loc: {
+      start: { column: 22, line: 1 },
+      end: { column: 23, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "(",
+
+    range: [23, 24],
+    loc: {
+      start: { column: 23, line: 1 },
+      end: { column: 24, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ")",
+
+    range: [24, 25],
+    loc: {
+      start: { column: 24, line: 1 },
+      end: { column: 25, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ";",
+
+    range: [25, 26],
+    loc: {
+      start: { column: 25, line: 1 },
+      end: { column: 26, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/type-param-one/snapshots/3-Babel-AST.shot b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/type-param-one/snapshots/3-Babel-AST.shot
new file mode 100644
index 000000000000..745e9cba3935
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/type-param-one/snapshots/3-Babel-AST.shot
@@ -0,0 +1,61 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSDeclareFunction type-param-one Babel - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    TSDeclareFunction {
+      type: "TSDeclareFunction",
+      async: false,
+      declare: true,
+      expression: false,
+      generator: false,
+      id: Identifier {
+        type: "Identifier",
+        name: "foo",
+
+        range: [17, 20],
+        loc: {
+          start: { column: 17, line: 1 },
+          end: { column: 20, line: 1 },
+        },
+      },
+      params: Array [],
+      typeParameters: TSTypeParameterDeclaration {
+        type: "TSTypeParameterDeclaration",
+        params: Array [
+          TSTypeParameter {
+            type: "TSTypeParameter",
+            name: "T",
+
+            range: [21, 22],
+            loc: {
+              start: { column: 21, line: 1 },
+              end: { column: 22, line: 1 },
+            },
+          },
+        ],
+
+        range: [20, 23],
+        loc: {
+          start: { column: 20, line: 1 },
+          end: { column: 23, line: 1 },
+        },
+      },
+
+      range: [0, 26],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 26, line: 1 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 27],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/type-param-one/snapshots/4-Babel-Tokens.shot b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/type-param-one/snapshots/4-Babel-Tokens.shot
new file mode 100644
index 000000000000..8f4c003543d6
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/type-param-one/snapshots/4-Babel-Tokens.shot
@@ -0,0 +1,96 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSDeclareFunction type-param-one Babel - Tokens 1`] = `
+Array [
+  Identifier {
+    type: "Identifier",
+    value: "declare",
+
+    range: [0, 7],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 7, line: 1 },
+    },
+  },
+  Keyword {
+    type: "Keyword",
+    value: "function",
+
+    range: [8, 16],
+    loc: {
+      start: { column: 8, line: 1 },
+      end: { column: 16, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "foo",
+
+    range: [17, 20],
+    loc: {
+      start: { column: 17, line: 1 },
+      end: { column: 20, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "<",
+
+    range: [20, 21],
+    loc: {
+      start: { column: 20, line: 1 },
+      end: { column: 21, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "T",
+
+    range: [21, 22],
+    loc: {
+      start: { column: 21, line: 1 },
+      end: { column: 22, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ">",
+
+    range: [22, 23],
+    loc: {
+      start: { column: 22, line: 1 },
+      end: { column: 23, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "(",
+
+    range: [23, 24],
+    loc: {
+      start: { column: 23, line: 1 },
+      end: { column: 24, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ")",
+
+    range: [24, 25],
+    loc: {
+      start: { column: 24, line: 1 },
+      end: { column: 25, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ";",
+
+    range: [25, 26],
+    loc: {
+      start: { column: 25, line: 1 },
+      end: { column: 26, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/type-param-one/snapshots/5-AST-Alignment-AST.shot b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/type-param-one/snapshots/5-AST-Alignment-AST.shot
new file mode 100644
index 000000000000..6763966b08fc
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/type-param-one/snapshots/5-AST-Alignment-AST.shot
@@ -0,0 +1,77 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSDeclareFunction type-param-one AST Alignment - AST 1`] = `
+"Snapshot Diff:
+- TSESTree
++ Babel
+
+  Program {
+    type: 'Program',
+    body: Array [
+      TSDeclareFunction {
+        type: 'TSDeclareFunction',
+        async: false,
+        declare: true,
+        expression: false,
+        generator: false,
+        id: Identifier {
+          type: 'Identifier',
+          name: 'foo',
+
+          range: [17, 20],
+          loc: {
+            start: { column: 17, line: 1 },
+            end: { column: 20, line: 1 },
+          },
+        },
+        params: Array [],
+        typeParameters: TSTypeParameterDeclaration {
+          type: 'TSTypeParameterDeclaration',
+          params: Array [
+            TSTypeParameter {
+              type: 'TSTypeParameter',
+-             in: false,
+-             name: Identifier {
+-               type: 'Identifier',
+-               name: 'T',
+-
+-               range: [21, 22],
+-               loc: {
+-                 start: { column: 21, line: 1 },
+-                 end: { column: 22, line: 1 },
+-               },
+-             },
+-             out: false,
++             name: 'T',
+
+              range: [21, 22],
+              loc: {
+                start: { column: 21, line: 1 },
+                end: { column: 22, line: 1 },
+              },
+            },
+          ],
+
+          range: [20, 23],
+          loc: {
+            start: { column: 20, line: 1 },
+            end: { column: 23, line: 1 },
+          },
+        },
+
+        range: [0, 26],
+        loc: {
+          start: { column: 0, line: 1 },
+          end: { column: 26, line: 1 },
+        },
+      },
+    ],
+    sourceType: 'script',
+
+    range: [0, 27],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 0, line: 2 },
+    },
+  }"
+`;
diff --git a/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/type-param-one/snapshots/6-AST-Alignment-Tokens.shot b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/type-param-one/snapshots/6-AST-Alignment-Tokens.shot
new file mode 100644
index 000000000000..669ef13533fa
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/type-param-one/snapshots/6-AST-Alignment-Tokens.shot
@@ -0,0 +1,6 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSDeclareFunction type-param-one AST Alignment - Token 1`] = `
+"Snapshot Diff:
+Compared values have no visual difference."
+`;
diff --git a/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/without-declare/fixture.ts b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/without-declare/fixture.ts
new file mode 100644
index 000000000000..242942bf817d
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/without-declare/fixture.ts
@@ -0,0 +1 @@
+function foo(): void;
diff --git a/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/without-declare/snapshots/1-TSESTree-AST.shot b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/without-declare/snapshots/1-TSESTree-AST.shot
new file mode 100644
index 000000000000..5c46a6508afd
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/without-declare/snapshots/1-TSESTree-AST.shot
@@ -0,0 +1,57 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSDeclareFunction without-declare TSESTree - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    TSDeclareFunction {
+      type: "TSDeclareFunction",
+      async: false,
+      expression: false,
+      generator: false,
+      id: Identifier {
+        type: "Identifier",
+        name: "foo",
+
+        range: [9, 12],
+        loc: {
+          start: { column: 9, line: 1 },
+          end: { column: 12, line: 1 },
+        },
+      },
+      params: Array [],
+      returnType: TSTypeAnnotation {
+        type: "TSTypeAnnotation",
+        typeAnnotation: TSVoidKeyword {
+          type: "TSVoidKeyword",
+
+          range: [16, 20],
+          loc: {
+            start: { column: 16, line: 1 },
+            end: { column: 20, line: 1 },
+          },
+        },
+
+        range: [14, 20],
+        loc: {
+          start: { column: 14, line: 1 },
+          end: { column: 20, line: 1 },
+        },
+      },
+
+      range: [0, 21],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 21, line: 1 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 22],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/without-declare/snapshots/2-TSESTree-Tokens.shot b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/without-declare/snapshots/2-TSESTree-Tokens.shot
new file mode 100644
index 000000000000..67a00cfbc1a0
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/without-declare/snapshots/2-TSESTree-Tokens.shot
@@ -0,0 +1,76 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSDeclareFunction without-declare TSESTree - Tokens 1`] = `
+Array [
+  Keyword {
+    type: "Keyword",
+    value: "function",
+
+    range: [0, 8],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 8, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "foo",
+
+    range: [9, 12],
+    loc: {
+      start: { column: 9, line: 1 },
+      end: { column: 12, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "(",
+
+    range: [12, 13],
+    loc: {
+      start: { column: 12, line: 1 },
+      end: { column: 13, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ")",
+
+    range: [13, 14],
+    loc: {
+      start: { column: 13, line: 1 },
+      end: { column: 14, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ":",
+
+    range: [14, 15],
+    loc: {
+      start: { column: 14, line: 1 },
+      end: { column: 15, line: 1 },
+    },
+  },
+  Keyword {
+    type: "Keyword",
+    value: "void",
+
+    range: [16, 20],
+    loc: {
+      start: { column: 16, line: 1 },
+      end: { column: 20, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ";",
+
+    range: [20, 21],
+    loc: {
+      start: { column: 20, line: 1 },
+      end: { column: 21, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/without-declare/snapshots/3-Babel-AST.shot b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/without-declare/snapshots/3-Babel-AST.shot
new file mode 100644
index 000000000000..2e49a416b762
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/without-declare/snapshots/3-Babel-AST.shot
@@ -0,0 +1,57 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSDeclareFunction without-declare Babel - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    TSDeclareFunction {
+      type: "TSDeclareFunction",
+      async: false,
+      expression: false,
+      generator: false,
+      id: Identifier {
+        type: "Identifier",
+        name: "foo",
+
+        range: [9, 12],
+        loc: {
+          start: { column: 9, line: 1 },
+          end: { column: 12, line: 1 },
+        },
+      },
+      params: Array [],
+      returnType: TSTypeAnnotation {
+        type: "TSTypeAnnotation",
+        typeAnnotation: TSVoidKeyword {
+          type: "TSVoidKeyword",
+
+          range: [16, 20],
+          loc: {
+            start: { column: 16, line: 1 },
+            end: { column: 20, line: 1 },
+          },
+        },
+
+        range: [14, 20],
+        loc: {
+          start: { column: 14, line: 1 },
+          end: { column: 20, line: 1 },
+        },
+      },
+
+      range: [0, 21],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 21, line: 1 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 22],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/without-declare/snapshots/4-Babel-Tokens.shot b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/without-declare/snapshots/4-Babel-Tokens.shot
new file mode 100644
index 000000000000..0c6751d92ced
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/without-declare/snapshots/4-Babel-Tokens.shot
@@ -0,0 +1,76 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSDeclareFunction without-declare Babel - Tokens 1`] = `
+Array [
+  Keyword {
+    type: "Keyword",
+    value: "function",
+
+    range: [0, 8],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 8, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "foo",
+
+    range: [9, 12],
+    loc: {
+      start: { column: 9, line: 1 },
+      end: { column: 12, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "(",
+
+    range: [12, 13],
+    loc: {
+      start: { column: 12, line: 1 },
+      end: { column: 13, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ")",
+
+    range: [13, 14],
+    loc: {
+      start: { column: 13, line: 1 },
+      end: { column: 14, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ":",
+
+    range: [14, 15],
+    loc: {
+      start: { column: 14, line: 1 },
+      end: { column: 15, line: 1 },
+    },
+  },
+  Keyword {
+    type: "Keyword",
+    value: "void",
+
+    range: [16, 20],
+    loc: {
+      start: { column: 16, line: 1 },
+      end: { column: 20, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ";",
+
+    range: [20, 21],
+    loc: {
+      start: { column: 20, line: 1 },
+      end: { column: 21, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/without-declare/snapshots/5-AST-Alignment-AST.shot b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/without-declare/snapshots/5-AST-Alignment-AST.shot
new file mode 100644
index 000000000000..7f5b5b1b141d
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/without-declare/snapshots/5-AST-Alignment-AST.shot
@@ -0,0 +1,6 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSDeclareFunction without-declare AST Alignment - AST 1`] = `
+"Snapshot Diff:
+Compared values have no visual difference."
+`;
diff --git a/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/without-declare/snapshots/6-AST-Alignment-Tokens.shot b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/without-declare/snapshots/6-AST-Alignment-Tokens.shot
new file mode 100644
index 000000000000..9995b1b0eb91
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSDeclareFunction/fixtures/without-declare/snapshots/6-AST-Alignment-Tokens.shot
@@ -0,0 +1,6 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSDeclareFunction without-declare AST Alignment - Token 1`] = `
+"Snapshot Diff:
+Compared values have no visual difference."
+`;
diff --git a/packages/ast-spec/src/declaration/TSDeclareFunction/spec.ts b/packages/ast-spec/src/declaration/TSDeclareFunction/spec.ts
index 88bd4aff2f21..ea37a1e874f6 100644
--- a/packages/ast-spec/src/declaration/TSDeclareFunction/spec.ts
+++ b/packages/ast-spec/src/declaration/TSDeclareFunction/spec.ts
@@ -1,6 +1,13 @@
 import type { AST_NODE_TYPES } from '../../ast-node-types';
-import type { FunctionDeclarationBase } from '../../base/FunctionDeclarationBase';
+import type { FunctionBase } from '../../base/FunctionBase';
+import type { BlockStatement } from '../../statement/BlockStatement/spec';
 
-export interface TSDeclareFunction extends FunctionDeclarationBase {
+// TODO(#1852) - async + declare are semantically invalid together
+export interface TSDeclareFunction extends FunctionBase {
   type: AST_NODE_TYPES.TSDeclareFunction;
+  // TODO(#1852) - breaking change enforce this is always `null` like `TSEmptyBodyFunctionExpression`
+  body?: BlockStatement;
+  // TODO(#5020) - make this always `false` if it is not `declare`d instead of `undefined`
+  declare?: boolean;
+  expression: false;
 }
diff --git a/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/_error_/missing-body/fixture.ts b/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/_error_/missing-body/fixture.ts
new file mode 100644
index 000000000000..eeaa8c95655f
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/_error_/missing-body/fixture.ts
@@ -0,0 +1 @@
+enum Foo;
diff --git a/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/_error_/missing-body/snapshots/1-TSESTree-Error.shot b/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/_error_/missing-body/snapshots/1-TSESTree-Error.shot
new file mode 100644
index 000000000000..898964994760
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/_error_/missing-body/snapshots/1-TSESTree-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSEnumDeclaration _error_ missing-body TSESTree - Error 1`] = `[TSError: '{' expected.]`;
diff --git a/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/_error_/missing-body/snapshots/2-Babel-Error.shot b/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/_error_/missing-body/snapshots/2-Babel-Error.shot
new file mode 100644
index 000000000000..69fc4aef1475
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/_error_/missing-body/snapshots/2-Babel-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSEnumDeclaration _error_ missing-body Babel - Error 1`] = `[SyntaxError: Unexpected token, expected "{" (1:8)]`;
diff --git a/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/_error_/missing-body/snapshots/3-Alignment-Error.shot b/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/_error_/missing-body/snapshots/3-Alignment-Error.shot
new file mode 100644
index 000000000000..4d1d30b58b60
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/_error_/missing-body/snapshots/3-Alignment-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSEnumDeclaration _error_ missing-body Error Alignment 1`] = `"Both errored"`;
diff --git a/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/_error_/missing-id/fixture.ts b/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/_error_/missing-id/fixture.ts
new file mode 100644
index 000000000000..14404051ead9
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/_error_/missing-id/fixture.ts
@@ -0,0 +1 @@
+enum {}
diff --git a/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/_error_/missing-id/snapshots/1-TSESTree-Error.shot b/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/_error_/missing-id/snapshots/1-TSESTree-Error.shot
new file mode 100644
index 000000000000..0653a9025ef0
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/_error_/missing-id/snapshots/1-TSESTree-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSEnumDeclaration _error_ missing-id TSESTree - Error 1`] = `[TSError: Identifier expected.]`;
diff --git a/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/_error_/missing-id/snapshots/2-Babel-Error.shot b/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/_error_/missing-id/snapshots/2-Babel-Error.shot
new file mode 100644
index 000000000000..676c0503e372
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/_error_/missing-id/snapshots/2-Babel-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSEnumDeclaration _error_ missing-id Babel - Error 1`] = `[SyntaxError: Unexpected token (1:5)]`;
diff --git a/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/_error_/missing-id/snapshots/3-Alignment-Error.shot b/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/_error_/missing-id/snapshots/3-Alignment-Error.shot
new file mode 100644
index 000000000000..5fb97329274d
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/_error_/missing-id/snapshots/3-Alignment-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSEnumDeclaration _error_ missing-id Error Alignment 1`] = `"Both errored"`;
diff --git a/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/_error_/non-identifier-name/fixture.ts b/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/_error_/non-identifier-name/fixture.ts
new file mode 100644
index 000000000000..9089db7067dc
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/_error_/non-identifier-name/fixture.ts
@@ -0,0 +1 @@
+enum 1 {}
diff --git a/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/_error_/non-identifier-name/snapshots/1-TSESTree-Error.shot b/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/_error_/non-identifier-name/snapshots/1-TSESTree-Error.shot
new file mode 100644
index 000000000000..15a27efccaf5
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/_error_/non-identifier-name/snapshots/1-TSESTree-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSEnumDeclaration _error_ non-identifier-name TSESTree - Error 1`] = `[TSError: Identifier expected.]`;
diff --git a/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/_error_/non-identifier-name/snapshots/2-Babel-Error.shot b/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/_error_/non-identifier-name/snapshots/2-Babel-Error.shot
new file mode 100644
index 000000000000..1cf8f0ab8999
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/_error_/non-identifier-name/snapshots/2-Babel-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSEnumDeclaration _error_ non-identifier-name Babel - Error 1`] = `[SyntaxError: Unexpected token (1:5)]`;
diff --git a/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/_error_/non-identifier-name/snapshots/3-Alignment-Error.shot b/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/_error_/non-identifier-name/snapshots/3-Alignment-Error.shot
new file mode 100644
index 000000000000..dd5c61750081
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/_error_/non-identifier-name/snapshots/3-Alignment-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSEnumDeclaration _error_ non-identifier-name Error Alignment 1`] = `"Both errored"`;
diff --git a/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/const/fixture.ts b/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/const/fixture.ts
new file mode 100644
index 000000000000..97b096b8754b
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/const/fixture.ts
@@ -0,0 +1 @@
+const enum Foo {}
diff --git a/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/const/snapshots/1-TSESTree-AST.shot b/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/const/snapshots/1-TSESTree-AST.shot
new file mode 100644
index 000000000000..1d59f828b678
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/const/snapshots/1-TSESTree-AST.shot
@@ -0,0 +1,37 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSEnumDeclaration const TSESTree - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    TSEnumDeclaration {
+      type: "TSEnumDeclaration",
+      const: true,
+      id: Identifier {
+        type: "Identifier",
+        name: "Foo",
+
+        range: [11, 14],
+        loc: {
+          start: { column: 11, line: 1 },
+          end: { column: 14, line: 1 },
+        },
+      },
+      members: Array [],
+
+      range: [0, 17],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 17, line: 1 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 18],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/const/snapshots/2-TSESTree-Tokens.shot b/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/const/snapshots/2-TSESTree-Tokens.shot
new file mode 100644
index 000000000000..a25cddd52f6a
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/const/snapshots/2-TSESTree-Tokens.shot
@@ -0,0 +1,56 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSEnumDeclaration const TSESTree - Tokens 1`] = `
+Array [
+  Keyword {
+    type: "Keyword",
+    value: "const",
+
+    range: [0, 5],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 5, line: 1 },
+    },
+  },
+  Keyword {
+    type: "Keyword",
+    value: "enum",
+
+    range: [6, 10],
+    loc: {
+      start: { column: 6, line: 1 },
+      end: { column: 10, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "Foo",
+
+    range: [11, 14],
+    loc: {
+      start: { column: 11, line: 1 },
+      end: { column: 14, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "{",
+
+    range: [15, 16],
+    loc: {
+      start: { column: 15, line: 1 },
+      end: { column: 16, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "}",
+
+    range: [16, 17],
+    loc: {
+      start: { column: 16, line: 1 },
+      end: { column: 17, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/const/snapshots/3-Babel-AST.shot b/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/const/snapshots/3-Babel-AST.shot
new file mode 100644
index 000000000000..5ee7fea32e6f
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/const/snapshots/3-Babel-AST.shot
@@ -0,0 +1,37 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSEnumDeclaration const Babel - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    TSEnumDeclaration {
+      type: "TSEnumDeclaration",
+      const: true,
+      id: Identifier {
+        type: "Identifier",
+        name: "Foo",
+
+        range: [11, 14],
+        loc: {
+          start: { column: 11, line: 1 },
+          end: { column: 14, line: 1 },
+        },
+      },
+      members: Array [],
+
+      range: [0, 17],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 17, line: 1 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 18],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/const/snapshots/4-Babel-Tokens.shot b/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/const/snapshots/4-Babel-Tokens.shot
new file mode 100644
index 000000000000..4a4ccaf3ecc8
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/const/snapshots/4-Babel-Tokens.shot
@@ -0,0 +1,56 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSEnumDeclaration const Babel - Tokens 1`] = `
+Array [
+  Keyword {
+    type: "Keyword",
+    value: "const",
+
+    range: [0, 5],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 5, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "enum",
+
+    range: [6, 10],
+    loc: {
+      start: { column: 6, line: 1 },
+      end: { column: 10, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "Foo",
+
+    range: [11, 14],
+    loc: {
+      start: { column: 11, line: 1 },
+      end: { column: 14, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "{",
+
+    range: [15, 16],
+    loc: {
+      start: { column: 15, line: 1 },
+      end: { column: 16, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "}",
+
+    range: [16, 17],
+    loc: {
+      start: { column: 16, line: 1 },
+      end: { column: 17, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/const/snapshots/5-AST-Alignment-AST.shot b/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/const/snapshots/5-AST-Alignment-AST.shot
new file mode 100644
index 000000000000..95d4c8f6b4a0
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/const/snapshots/5-AST-Alignment-AST.shot
@@ -0,0 +1,6 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSEnumDeclaration const AST Alignment - AST 1`] = `
+"Snapshot Diff:
+Compared values have no visual difference."
+`;
diff --git a/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/const/snapshots/6-AST-Alignment-Tokens.shot b/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/const/snapshots/6-AST-Alignment-Tokens.shot
new file mode 100644
index 000000000000..2e994fa6ae9e
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/const/snapshots/6-AST-Alignment-Tokens.shot
@@ -0,0 +1,62 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSEnumDeclaration const AST Alignment - Token 1`] = `
+"Snapshot Diff:
+- TSESTree
++ Babel
+
+  Array [
+    Keyword {
+      type: 'Keyword',
+      value: 'const',
+
+      range: [0, 5],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 5, line: 1 },
+      },
+    },
+-   Keyword {
+-     type: 'Keyword',
++   Identifier {
++     type: 'Identifier',
+      value: 'enum',
+
+      range: [6, 10],
+      loc: {
+        start: { column: 6, line: 1 },
+        end: { column: 10, line: 1 },
+      },
+    },
+    Identifier {
+      type: 'Identifier',
+      value: 'Foo',
+
+      range: [11, 14],
+      loc: {
+        start: { column: 11, line: 1 },
+        end: { column: 14, line: 1 },
+      },
+    },
+    Punctuator {
+      type: 'Punctuator',
+      value: '{',
+
+      range: [15, 16],
+      loc: {
+        start: { column: 15, line: 1 },
+        end: { column: 16, line: 1 },
+      },
+    },
+    Punctuator {
+      type: 'Punctuator',
+      value: '}',
+
+      range: [16, 17],
+      loc: {
+        start: { column: 16, line: 1 },
+        end: { column: 17, line: 1 },
+      },
+    },
+  ]"
+`;
diff --git a/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/declare/fixture.ts b/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/declare/fixture.ts
new file mode 100644
index 000000000000..6ec0c1cbf6a2
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/declare/fixture.ts
@@ -0,0 +1 @@
+declare enum Foo {}
diff --git a/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/declare/snapshots/1-TSESTree-AST.shot b/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/declare/snapshots/1-TSESTree-AST.shot
new file mode 100644
index 000000000000..8b742184ed94
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/declare/snapshots/1-TSESTree-AST.shot
@@ -0,0 +1,37 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSEnumDeclaration declare TSESTree - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    TSEnumDeclaration {
+      type: "TSEnumDeclaration",
+      declare: true,
+      id: Identifier {
+        type: "Identifier",
+        name: "Foo",
+
+        range: [13, 16],
+        loc: {
+          start: { column: 13, line: 1 },
+          end: { column: 16, line: 1 },
+        },
+      },
+      members: Array [],
+
+      range: [0, 19],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 19, line: 1 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 20],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/declare/snapshots/2-TSESTree-Tokens.shot b/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/declare/snapshots/2-TSESTree-Tokens.shot
new file mode 100644
index 000000000000..b045362a4c54
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/declare/snapshots/2-TSESTree-Tokens.shot
@@ -0,0 +1,56 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSEnumDeclaration declare TSESTree - Tokens 1`] = `
+Array [
+  Identifier {
+    type: "Identifier",
+    value: "declare",
+
+    range: [0, 7],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 7, line: 1 },
+    },
+  },
+  Keyword {
+    type: "Keyword",
+    value: "enum",
+
+    range: [8, 12],
+    loc: {
+      start: { column: 8, line: 1 },
+      end: { column: 12, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "Foo",
+
+    range: [13, 16],
+    loc: {
+      start: { column: 13, line: 1 },
+      end: { column: 16, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "{",
+
+    range: [17, 18],
+    loc: {
+      start: { column: 17, line: 1 },
+      end: { column: 18, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "}",
+
+    range: [18, 19],
+    loc: {
+      start: { column: 18, line: 1 },
+      end: { column: 19, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/declare/snapshots/3-Babel-AST.shot b/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/declare/snapshots/3-Babel-AST.shot
new file mode 100644
index 000000000000..21a3e86cd15c
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/declare/snapshots/3-Babel-AST.shot
@@ -0,0 +1,37 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSEnumDeclaration declare Babel - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    TSEnumDeclaration {
+      type: "TSEnumDeclaration",
+      declare: true,
+      id: Identifier {
+        type: "Identifier",
+        name: "Foo",
+
+        range: [13, 16],
+        loc: {
+          start: { column: 13, line: 1 },
+          end: { column: 16, line: 1 },
+        },
+      },
+      members: Array [],
+
+      range: [0, 19],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 19, line: 1 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 20],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/declare/snapshots/4-Babel-Tokens.shot b/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/declare/snapshots/4-Babel-Tokens.shot
new file mode 100644
index 000000000000..ccf2a20885e8
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/declare/snapshots/4-Babel-Tokens.shot
@@ -0,0 +1,56 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSEnumDeclaration declare Babel - Tokens 1`] = `
+Array [
+  Identifier {
+    type: "Identifier",
+    value: "declare",
+
+    range: [0, 7],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 7, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "enum",
+
+    range: [8, 12],
+    loc: {
+      start: { column: 8, line: 1 },
+      end: { column: 12, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "Foo",
+
+    range: [13, 16],
+    loc: {
+      start: { column: 13, line: 1 },
+      end: { column: 16, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "{",
+
+    range: [17, 18],
+    loc: {
+      start: { column: 17, line: 1 },
+      end: { column: 18, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "}",
+
+    range: [18, 19],
+    loc: {
+      start: { column: 18, line: 1 },
+      end: { column: 19, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/declare/snapshots/5-AST-Alignment-AST.shot b/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/declare/snapshots/5-AST-Alignment-AST.shot
new file mode 100644
index 000000000000..5085b6b4609b
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/declare/snapshots/5-AST-Alignment-AST.shot
@@ -0,0 +1,6 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSEnumDeclaration declare AST Alignment - AST 1`] = `
+"Snapshot Diff:
+Compared values have no visual difference."
+`;
diff --git a/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/declare/snapshots/6-AST-Alignment-Tokens.shot b/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/declare/snapshots/6-AST-Alignment-Tokens.shot
new file mode 100644
index 000000000000..11a6693745f4
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/declare/snapshots/6-AST-Alignment-Tokens.shot
@@ -0,0 +1,62 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSEnumDeclaration declare AST Alignment - Token 1`] = `
+"Snapshot Diff:
+- TSESTree
++ Babel
+
+  Array [
+    Identifier {
+      type: 'Identifier',
+      value: 'declare',
+
+      range: [0, 7],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 7, line: 1 },
+      },
+    },
+-   Keyword {
+-     type: 'Keyword',
++   Identifier {
++     type: 'Identifier',
+      value: 'enum',
+
+      range: [8, 12],
+      loc: {
+        start: { column: 8, line: 1 },
+        end: { column: 12, line: 1 },
+      },
+    },
+    Identifier {
+      type: 'Identifier',
+      value: 'Foo',
+
+      range: [13, 16],
+      loc: {
+        start: { column: 13, line: 1 },
+        end: { column: 16, line: 1 },
+      },
+    },
+    Punctuator {
+      type: 'Punctuator',
+      value: '{',
+
+      range: [17, 18],
+      loc: {
+        start: { column: 17, line: 1 },
+        end: { column: 18, line: 1 },
+      },
+    },
+    Punctuator {
+      type: 'Punctuator',
+      value: '}',
+
+      range: [18, 19],
+      loc: {
+        start: { column: 18, line: 1 },
+        end: { column: 19, line: 1 },
+      },
+    },
+  ]"
+`;
diff --git a/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/empty/fixture.ts b/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/empty/fixture.ts
new file mode 100644
index 000000000000..f418fb66f4f1
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/empty/fixture.ts
@@ -0,0 +1 @@
+enum Foo {}
diff --git a/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/empty/snapshots/1-TSESTree-AST.shot b/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/empty/snapshots/1-TSESTree-AST.shot
new file mode 100644
index 000000000000..85e4f093eb2f
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/empty/snapshots/1-TSESTree-AST.shot
@@ -0,0 +1,36 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSEnumDeclaration empty TSESTree - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    TSEnumDeclaration {
+      type: "TSEnumDeclaration",
+      id: Identifier {
+        type: "Identifier",
+        name: "Foo",
+
+        range: [5, 8],
+        loc: {
+          start: { column: 5, line: 1 },
+          end: { column: 8, line: 1 },
+        },
+      },
+      members: Array [],
+
+      range: [0, 11],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 11, line: 1 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 12],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/empty/snapshots/2-TSESTree-Tokens.shot b/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/empty/snapshots/2-TSESTree-Tokens.shot
new file mode 100644
index 000000000000..c419adb83097
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/empty/snapshots/2-TSESTree-Tokens.shot
@@ -0,0 +1,46 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSEnumDeclaration empty TSESTree - Tokens 1`] = `
+Array [
+  Keyword {
+    type: "Keyword",
+    value: "enum",
+
+    range: [0, 4],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 4, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "Foo",
+
+    range: [5, 8],
+    loc: {
+      start: { column: 5, line: 1 },
+      end: { column: 8, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "{",
+
+    range: [9, 10],
+    loc: {
+      start: { column: 9, line: 1 },
+      end: { column: 10, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "}",
+
+    range: [10, 11],
+    loc: {
+      start: { column: 10, line: 1 },
+      end: { column: 11, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/empty/snapshots/3-Babel-AST.shot b/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/empty/snapshots/3-Babel-AST.shot
new file mode 100644
index 000000000000..79ad82443c71
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/empty/snapshots/3-Babel-AST.shot
@@ -0,0 +1,36 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSEnumDeclaration empty Babel - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    TSEnumDeclaration {
+      type: "TSEnumDeclaration",
+      id: Identifier {
+        type: "Identifier",
+        name: "Foo",
+
+        range: [5, 8],
+        loc: {
+          start: { column: 5, line: 1 },
+          end: { column: 8, line: 1 },
+        },
+      },
+      members: Array [],
+
+      range: [0, 11],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 11, line: 1 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 12],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/empty/snapshots/4-Babel-Tokens.shot b/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/empty/snapshots/4-Babel-Tokens.shot
new file mode 100644
index 000000000000..688f75fe0f2b
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/empty/snapshots/4-Babel-Tokens.shot
@@ -0,0 +1,46 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSEnumDeclaration empty Babel - Tokens 1`] = `
+Array [
+  Identifier {
+    type: "Identifier",
+    value: "enum",
+
+    range: [0, 4],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 4, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "Foo",
+
+    range: [5, 8],
+    loc: {
+      start: { column: 5, line: 1 },
+      end: { column: 8, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "{",
+
+    range: [9, 10],
+    loc: {
+      start: { column: 9, line: 1 },
+      end: { column: 10, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "}",
+
+    range: [10, 11],
+    loc: {
+      start: { column: 10, line: 1 },
+      end: { column: 11, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/empty/snapshots/5-AST-Alignment-AST.shot b/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/empty/snapshots/5-AST-Alignment-AST.shot
new file mode 100644
index 000000000000..2ce5c714db11
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/empty/snapshots/5-AST-Alignment-AST.shot
@@ -0,0 +1,6 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSEnumDeclaration empty AST Alignment - AST 1`] = `
+"Snapshot Diff:
+Compared values have no visual difference."
+`;
diff --git a/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/empty/snapshots/6-AST-Alignment-Tokens.shot b/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/empty/snapshots/6-AST-Alignment-Tokens.shot
new file mode 100644
index 000000000000..5c9479e0ff80
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/empty/snapshots/6-AST-Alignment-Tokens.shot
@@ -0,0 +1,52 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSEnumDeclaration empty AST Alignment - Token 1`] = `
+"Snapshot Diff:
+- TSESTree
++ Babel
+
+  Array [
+-   Keyword {
+-     type: 'Keyword',
++   Identifier {
++     type: 'Identifier',
+      value: 'enum',
+
+      range: [0, 4],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 4, line: 1 },
+      },
+    },
+    Identifier {
+      type: 'Identifier',
+      value: 'Foo',
+
+      range: [5, 8],
+      loc: {
+        start: { column: 5, line: 1 },
+        end: { column: 8, line: 1 },
+      },
+    },
+    Punctuator {
+      type: 'Punctuator',
+      value: '{',
+
+      range: [9, 10],
+      loc: {
+        start: { column: 9, line: 1 },
+        end: { column: 10, line: 1 },
+      },
+    },
+    Punctuator {
+      type: 'Punctuator',
+      value: '}',
+
+      range: [10, 11],
+      loc: {
+        start: { column: 10, line: 1 },
+        end: { column: 11, line: 1 },
+      },
+    },
+  ]"
+`;
diff --git a/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/with-member-one/fixture.ts b/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/with-member-one/fixture.ts
new file mode 100644
index 000000000000..a639ff46e1b4
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/with-member-one/fixture.ts
@@ -0,0 +1,3 @@
+enum Foo {
+  A,
+}
diff --git a/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/with-member-one/snapshots/1-TSESTree-AST.shot b/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/with-member-one/snapshots/1-TSESTree-AST.shot
new file mode 100644
index 000000000000..dc9b0027eed0
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/with-member-one/snapshots/1-TSESTree-AST.shot
@@ -0,0 +1,56 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSEnumDeclaration with-member-one TSESTree - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    TSEnumDeclaration {
+      type: "TSEnumDeclaration",
+      id: Identifier {
+        type: "Identifier",
+        name: "Foo",
+
+        range: [5, 8],
+        loc: {
+          start: { column: 5, line: 1 },
+          end: { column: 8, line: 1 },
+        },
+      },
+      members: Array [
+        TSEnumMember {
+          type: "TSEnumMember",
+          id: Identifier {
+            type: "Identifier",
+            name: "A",
+
+            range: [13, 14],
+            loc: {
+              start: { column: 2, line: 2 },
+              end: { column: 3, line: 2 },
+            },
+          },
+
+          range: [13, 14],
+          loc: {
+            start: { column: 2, line: 2 },
+            end: { column: 3, line: 2 },
+          },
+        },
+      ],
+
+      range: [0, 17],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 1, line: 3 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 18],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 4 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/with-member-one/snapshots/2-TSESTree-Tokens.shot b/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/with-member-one/snapshots/2-TSESTree-Tokens.shot
new file mode 100644
index 000000000000..e0ddd7d58be5
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/with-member-one/snapshots/2-TSESTree-Tokens.shot
@@ -0,0 +1,66 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSEnumDeclaration with-member-one TSESTree - Tokens 1`] = `
+Array [
+  Keyword {
+    type: "Keyword",
+    value: "enum",
+
+    range: [0, 4],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 4, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "Foo",
+
+    range: [5, 8],
+    loc: {
+      start: { column: 5, line: 1 },
+      end: { column: 8, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "{",
+
+    range: [9, 10],
+    loc: {
+      start: { column: 9, line: 1 },
+      end: { column: 10, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "A",
+
+    range: [13, 14],
+    loc: {
+      start: { column: 2, line: 2 },
+      end: { column: 3, line: 2 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ",",
+
+    range: [14, 15],
+    loc: {
+      start: { column: 3, line: 2 },
+      end: { column: 4, line: 2 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "}",
+
+    range: [16, 17],
+    loc: {
+      start: { column: 0, line: 3 },
+      end: { column: 1, line: 3 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/with-member-one/snapshots/3-Babel-AST.shot b/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/with-member-one/snapshots/3-Babel-AST.shot
new file mode 100644
index 000000000000..477613196944
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/with-member-one/snapshots/3-Babel-AST.shot
@@ -0,0 +1,56 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSEnumDeclaration with-member-one Babel - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    TSEnumDeclaration {
+      type: "TSEnumDeclaration",
+      id: Identifier {
+        type: "Identifier",
+        name: "Foo",
+
+        range: [5, 8],
+        loc: {
+          start: { column: 5, line: 1 },
+          end: { column: 8, line: 1 },
+        },
+      },
+      members: Array [
+        TSEnumMember {
+          type: "TSEnumMember",
+          id: Identifier {
+            type: "Identifier",
+            name: "A",
+
+            range: [13, 14],
+            loc: {
+              start: { column: 2, line: 2 },
+              end: { column: 3, line: 2 },
+            },
+          },
+
+          range: [13, 14],
+          loc: {
+            start: { column: 2, line: 2 },
+            end: { column: 3, line: 2 },
+          },
+        },
+      ],
+
+      range: [0, 17],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 1, line: 3 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 18],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 4 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/with-member-one/snapshots/4-Babel-Tokens.shot b/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/with-member-one/snapshots/4-Babel-Tokens.shot
new file mode 100644
index 000000000000..08d14feb8c4c
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/with-member-one/snapshots/4-Babel-Tokens.shot
@@ -0,0 +1,66 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSEnumDeclaration with-member-one Babel - Tokens 1`] = `
+Array [
+  Identifier {
+    type: "Identifier",
+    value: "enum",
+
+    range: [0, 4],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 4, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "Foo",
+
+    range: [5, 8],
+    loc: {
+      start: { column: 5, line: 1 },
+      end: { column: 8, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "{",
+
+    range: [9, 10],
+    loc: {
+      start: { column: 9, line: 1 },
+      end: { column: 10, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "A",
+
+    range: [13, 14],
+    loc: {
+      start: { column: 2, line: 2 },
+      end: { column: 3, line: 2 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ",",
+
+    range: [14, 15],
+    loc: {
+      start: { column: 3, line: 2 },
+      end: { column: 4, line: 2 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "}",
+
+    range: [16, 17],
+    loc: {
+      start: { column: 0, line: 3 },
+      end: { column: 1, line: 3 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/with-member-one/snapshots/5-AST-Alignment-AST.shot b/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/with-member-one/snapshots/5-AST-Alignment-AST.shot
new file mode 100644
index 000000000000..b707fc5d46bb
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/with-member-one/snapshots/5-AST-Alignment-AST.shot
@@ -0,0 +1,6 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSEnumDeclaration with-member-one AST Alignment - AST 1`] = `
+"Snapshot Diff:
+Compared values have no visual difference."
+`;
diff --git a/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/with-member-one/snapshots/6-AST-Alignment-Tokens.shot b/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/with-member-one/snapshots/6-AST-Alignment-Tokens.shot
new file mode 100644
index 000000000000..cf146a98eac1
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSEnumDeclaration/fixtures/with-member-one/snapshots/6-AST-Alignment-Tokens.shot
@@ -0,0 +1,72 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSEnumDeclaration with-member-one AST Alignment - Token 1`] = `
+"Snapshot Diff:
+- TSESTree
++ Babel
+
+  Array [
+-   Keyword {
+-     type: 'Keyword',
++   Identifier {
++     type: 'Identifier',
+      value: 'enum',
+
+      range: [0, 4],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 4, line: 1 },
+      },
+    },
+    Identifier {
+      type: 'Identifier',
+      value: 'Foo',
+
+      range: [5, 8],
+      loc: {
+        start: { column: 5, line: 1 },
+        end: { column: 8, line: 1 },
+      },
+    },
+    Punctuator {
+      type: 'Punctuator',
+      value: '{',
+
+      range: [9, 10],
+      loc: {
+        start: { column: 9, line: 1 },
+        end: { column: 10, line: 1 },
+      },
+    },
+    Identifier {
+      type: 'Identifier',
+      value: 'A',
+
+      range: [13, 14],
+      loc: {
+        start: { column: 2, line: 2 },
+        end: { column: 3, line: 2 },
+      },
+    },
+    Punctuator {
+      type: 'Punctuator',
+      value: ',',
+
+      range: [14, 15],
+      loc: {
+        start: { column: 3, line: 2 },
+        end: { column: 4, line: 2 },
+      },
+    },
+    Punctuator {
+      type: 'Punctuator',
+      value: '}',
+
+      range: [16, 17],
+      loc: {
+        start: { column: 0, line: 3 },
+        end: { column: 1, line: 3 },
+      },
+    },
+  ]"
+`;
diff --git a/packages/ast-spec/src/declaration/TSEnumDeclaration/spec.ts b/packages/ast-spec/src/declaration/TSEnumDeclaration/spec.ts
index 1c1530d501ff..9a0df845c5d8 100644
--- a/packages/ast-spec/src/declaration/TSEnumDeclaration/spec.ts
+++ b/packages/ast-spec/src/declaration/TSEnumDeclaration/spec.ts
@@ -6,9 +6,30 @@ import type { Modifier } from '../../unions/Modifier';
 
 export interface TSEnumDeclaration extends BaseNode {
   type: AST_NODE_TYPES.TSEnumDeclaration;
-  id: Identifier;
-  members: TSEnumMember[];
+  /**
+   * Whether this is a `const` enum.
+   * ```
+   * const enum Foo {...}
+   * ```
+   */
+  // TODO(#5020) - make this `false` if it is not `const`
   const?: boolean;
+  /**
+   * Whether this is a `declare`d enum.
+   * ```
+   * declare enum Foo {...}
+   * ```
+   */
+  // TODO(#5020) - make this `false` if it is not `declare`d
   declare?: boolean;
+  /**
+   * The enum name.
+   */
+  id: Identifier;
+  /**
+   * The enum members.
+   */
+  members: TSEnumMember[];
+  // TODO(#4759) - breaking change remove this
   modifiers?: Modifier[];
 }
diff --git a/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/_error_/entity-name-invalid/fixture.ts b/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/_error_/entity-name-invalid/fixture.ts
new file mode 100644
index 000000000000..7fe439305a48
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/_error_/entity-name-invalid/fixture.ts
@@ -0,0 +1 @@
+import F = 1;
diff --git a/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/_error_/entity-name-invalid/snapshots/1-TSESTree-Error.shot b/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/_error_/entity-name-invalid/snapshots/1-TSESTree-Error.shot
new file mode 100644
index 000000000000..3593291fdb2a
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/_error_/entity-name-invalid/snapshots/1-TSESTree-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSImportEqualsDeclaration _error_ entity-name-invalid TSESTree - Error 1`] = `[TSError: Identifier expected.]`;
diff --git a/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/_error_/entity-name-invalid/snapshots/2-Babel-Error.shot b/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/_error_/entity-name-invalid/snapshots/2-Babel-Error.shot
new file mode 100644
index 000000000000..d5cc0b77735b
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/_error_/entity-name-invalid/snapshots/2-Babel-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSImportEqualsDeclaration _error_ entity-name-invalid Babel - Error 1`] = `[SyntaxError: Unexpected token (1:11)]`;
diff --git a/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/_error_/entity-name-invalid/snapshots/3-Alignment-Error.shot b/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/_error_/entity-name-invalid/snapshots/3-Alignment-Error.shot
new file mode 100644
index 000000000000..463142c713f0
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/_error_/entity-name-invalid/snapshots/3-Alignment-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSImportEqualsDeclaration _error_ entity-name-invalid Error Alignment 1`] = `"Both errored"`;
diff --git a/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/_error_/external-module-ref-non-string/fixture.ts b/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/_error_/external-module-ref-non-string/fixture.ts
new file mode 100644
index 000000000000..b67ea934e8c0
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/_error_/external-module-ref-non-string/fixture.ts
@@ -0,0 +1 @@
+import F = require(1);
diff --git a/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/_error_/external-module-ref-non-string/snapshots/1-TSESTree-Error.shot b/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/_error_/external-module-ref-non-string/snapshots/1-TSESTree-Error.shot
new file mode 100644
index 000000000000..51aedf5fa316
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/_error_/external-module-ref-non-string/snapshots/1-TSESTree-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSImportEqualsDeclaration _error_ external-module-ref-non-string TSESTree - Error 1`] = `"NO ERROR"`;
diff --git a/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/_error_/external-module-ref-non-string/snapshots/2-Babel-Error.shot b/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/_error_/external-module-ref-non-string/snapshots/2-Babel-Error.shot
new file mode 100644
index 000000000000..b19940abe312
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/_error_/external-module-ref-non-string/snapshots/2-Babel-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSImportEqualsDeclaration _error_ external-module-ref-non-string Babel - Error 1`] = `[SyntaxError: Unexpected token (1:19)]`;
diff --git a/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/_error_/external-module-ref-non-string/snapshots/3-Alignment-Error.shot b/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/_error_/external-module-ref-non-string/snapshots/3-Alignment-Error.shot
new file mode 100644
index 000000000000..cda96c9ac3d2
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/_error_/external-module-ref-non-string/snapshots/3-Alignment-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSImportEqualsDeclaration _error_ external-module-ref-non-string Error Alignment 1`] = `"Babel errored but TSESTree didn't"`;
diff --git a/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/_error_/import-kind/fixture.ts b/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/_error_/import-kind/fixture.ts
new file mode 100644
index 000000000000..769999c5f680
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/_error_/import-kind/fixture.ts
@@ -0,0 +1,2 @@
+type T = 1;
+import type F = T;
diff --git a/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/_error_/import-kind/snapshots/1-TSESTree-Error.shot b/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/_error_/import-kind/snapshots/1-TSESTree-Error.shot
new file mode 100644
index 000000000000..387be14ced26
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/_error_/import-kind/snapshots/1-TSESTree-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSImportEqualsDeclaration _error_ import-kind TSESTree - Error 1`] = `"NO ERROR"`;
diff --git a/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/_error_/import-kind/snapshots/2-Babel-Error.shot b/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/_error_/import-kind/snapshots/2-Babel-Error.shot
new file mode 100644
index 000000000000..b8f9e5be4e4c
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/_error_/import-kind/snapshots/2-Babel-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSImportEqualsDeclaration _error_ import-kind Babel - Error 1`] = `[SyntaxError: An import alias can not use 'import type'. (2:16)]`;
diff --git a/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/_error_/import-kind/snapshots/3-Alignment-Error.shot b/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/_error_/import-kind/snapshots/3-Alignment-Error.shot
new file mode 100644
index 000000000000..d9472dcc7b67
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/_error_/import-kind/snapshots/3-Alignment-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSImportEqualsDeclaration _error_ import-kind Error Alignment 1`] = `"Babel errored but TSESTree didn't"`;
diff --git a/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/_error_/missing-id/fixture.ts b/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/_error_/missing-id/fixture.ts
new file mode 100644
index 000000000000..2b0ead218dd1
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/_error_/missing-id/fixture.ts
@@ -0,0 +1 @@
+import = A.B;
diff --git a/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/_error_/missing-id/snapshots/1-TSESTree-Error.shot b/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/_error_/missing-id/snapshots/1-TSESTree-Error.shot
new file mode 100644
index 000000000000..b5dc03a804c3
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/_error_/missing-id/snapshots/1-TSESTree-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSImportEqualsDeclaration _error_ missing-id TSESTree - Error 1`] = `[TSError: Declaration or statement expected.]`;
diff --git a/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/_error_/missing-id/snapshots/2-Babel-Error.shot b/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/_error_/missing-id/snapshots/2-Babel-Error.shot
new file mode 100644
index 000000000000..3c24250cf63a
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/_error_/missing-id/snapshots/2-Babel-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSImportEqualsDeclaration _error_ missing-id Babel - Error 1`] = `[SyntaxError: Unexpected token, expected "{" (1:7)]`;
diff --git a/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/_error_/missing-id/snapshots/3-Alignment-Error.shot b/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/_error_/missing-id/snapshots/3-Alignment-Error.shot
new file mode 100644
index 000000000000..3f9e697fc06c
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/_error_/missing-id/snapshots/3-Alignment-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSImportEqualsDeclaration _error_ missing-id Error Alignment 1`] = `"Both errored"`;
diff --git a/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/_error_/missing-reference/fixture.ts b/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/_error_/missing-reference/fixture.ts
new file mode 100644
index 000000000000..3ce78a91241f
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/_error_/missing-reference/fixture.ts
@@ -0,0 +1 @@
+import F;
diff --git a/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/_error_/missing-reference/snapshots/1-TSESTree-Error.shot b/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/_error_/missing-reference/snapshots/1-TSESTree-Error.shot
new file mode 100644
index 000000000000..cb33fd8279bc
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/_error_/missing-reference/snapshots/1-TSESTree-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSImportEqualsDeclaration _error_ missing-reference TSESTree - Error 1`] = `[TSError: '=' expected.]`;
diff --git a/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/_error_/missing-reference/snapshots/2-Babel-Error.shot b/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/_error_/missing-reference/snapshots/2-Babel-Error.shot
new file mode 100644
index 000000000000..6dcc0a599541
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/_error_/missing-reference/snapshots/2-Babel-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSImportEqualsDeclaration _error_ missing-reference Babel - Error 1`] = `[SyntaxError: Unexpected token, expected "from" (1:8)]`;
diff --git a/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/_error_/missing-reference/snapshots/3-Alignment-Error.shot b/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/_error_/missing-reference/snapshots/3-Alignment-Error.shot
new file mode 100644
index 000000000000..7a3b4167a3b2
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/_error_/missing-reference/snapshots/3-Alignment-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSImportEqualsDeclaration _error_ missing-reference Error Alignment 1`] = `"Both errored"`;
diff --git a/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/entity-name-many/fixture.ts b/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/entity-name-many/fixture.ts
new file mode 100644
index 000000000000..fdcbe7ffe415
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/entity-name-many/fixture.ts
@@ -0,0 +1 @@
+import F = A.B.C;
diff --git a/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/entity-name-many/snapshots/1-TSESTree-AST.shot b/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/entity-name-many/snapshots/1-TSESTree-AST.shot
new file mode 100644
index 000000000000..6d438a8c596e
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/entity-name-many/snapshots/1-TSESTree-AST.shot
@@ -0,0 +1,85 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSImportEqualsDeclaration entity-name-many TSESTree - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    TSImportEqualsDeclaration {
+      type: "TSImportEqualsDeclaration",
+      id: Identifier {
+        type: "Identifier",
+        name: "F",
+
+        range: [7, 8],
+        loc: {
+          start: { column: 7, line: 1 },
+          end: { column: 8, line: 1 },
+        },
+      },
+      importKind: "value",
+      isExport: false,
+      moduleReference: TSQualifiedName {
+        type: "TSQualifiedName",
+        left: TSQualifiedName {
+          type: "TSQualifiedName",
+          left: Identifier {
+            type: "Identifier",
+            name: "A",
+
+            range: [11, 12],
+            loc: {
+              start: { column: 11, line: 1 },
+              end: { column: 12, line: 1 },
+            },
+          },
+          right: Identifier {
+            type: "Identifier",
+            name: "B",
+
+            range: [13, 14],
+            loc: {
+              start: { column: 13, line: 1 },
+              end: { column: 14, line: 1 },
+            },
+          },
+
+          range: [11, 14],
+          loc: {
+            start: { column: 11, line: 1 },
+            end: { column: 14, line: 1 },
+          },
+        },
+        right: Identifier {
+          type: "Identifier",
+          name: "C",
+
+          range: [15, 16],
+          loc: {
+            start: { column: 15, line: 1 },
+            end: { column: 16, line: 1 },
+          },
+        },
+
+        range: [11, 16],
+        loc: {
+          start: { column: 11, line: 1 },
+          end: { column: 16, line: 1 },
+        },
+      },
+
+      range: [0, 17],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 17, line: 1 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 18],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/entity-name-many/snapshots/2-TSESTree-Tokens.shot b/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/entity-name-many/snapshots/2-TSESTree-Tokens.shot
new file mode 100644
index 000000000000..7d0291e8b8b2
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/entity-name-many/snapshots/2-TSESTree-Tokens.shot
@@ -0,0 +1,96 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSImportEqualsDeclaration entity-name-many TSESTree - Tokens 1`] = `
+Array [
+  Keyword {
+    type: "Keyword",
+    value: "import",
+
+    range: [0, 6],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 6, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "F",
+
+    range: [7, 8],
+    loc: {
+      start: { column: 7, line: 1 },
+      end: { column: 8, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "=",
+
+    range: [9, 10],
+    loc: {
+      start: { column: 9, line: 1 },
+      end: { column: 10, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "A",
+
+    range: [11, 12],
+    loc: {
+      start: { column: 11, line: 1 },
+      end: { column: 12, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ".",
+
+    range: [12, 13],
+    loc: {
+      start: { column: 12, line: 1 },
+      end: { column: 13, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "B",
+
+    range: [13, 14],
+    loc: {
+      start: { column: 13, line: 1 },
+      end: { column: 14, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ".",
+
+    range: [14, 15],
+    loc: {
+      start: { column: 14, line: 1 },
+      end: { column: 15, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "C",
+
+    range: [15, 16],
+    loc: {
+      start: { column: 15, line: 1 },
+      end: { column: 16, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ";",
+
+    range: [16, 17],
+    loc: {
+      start: { column: 16, line: 1 },
+      end: { column: 17, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/entity-name-many/snapshots/3-Babel-AST.shot b/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/entity-name-many/snapshots/3-Babel-AST.shot
new file mode 100644
index 000000000000..e4d68bb9f751
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/entity-name-many/snapshots/3-Babel-AST.shot
@@ -0,0 +1,85 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSImportEqualsDeclaration entity-name-many Babel - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    TSImportEqualsDeclaration {
+      type: "TSImportEqualsDeclaration",
+      id: Identifier {
+        type: "Identifier",
+        name: "F",
+
+        range: [7, 8],
+        loc: {
+          start: { column: 7, line: 1 },
+          end: { column: 8, line: 1 },
+        },
+      },
+      importKind: "value",
+      isExport: false,
+      moduleReference: TSQualifiedName {
+        type: "TSQualifiedName",
+        left: TSQualifiedName {
+          type: "TSQualifiedName",
+          left: Identifier {
+            type: "Identifier",
+            name: "A",
+
+            range: [11, 12],
+            loc: {
+              start: { column: 11, line: 1 },
+              end: { column: 12, line: 1 },
+            },
+          },
+          right: Identifier {
+            type: "Identifier",
+            name: "B",
+
+            range: [13, 14],
+            loc: {
+              start: { column: 13, line: 1 },
+              end: { column: 14, line: 1 },
+            },
+          },
+
+          range: [11, 14],
+          loc: {
+            start: { column: 11, line: 1 },
+            end: { column: 14, line: 1 },
+          },
+        },
+        right: Identifier {
+          type: "Identifier",
+          name: "C",
+
+          range: [15, 16],
+          loc: {
+            start: { column: 15, line: 1 },
+            end: { column: 16, line: 1 },
+          },
+        },
+
+        range: [11, 16],
+        loc: {
+          start: { column: 11, line: 1 },
+          end: { column: 16, line: 1 },
+        },
+      },
+
+      range: [0, 17],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 17, line: 1 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 18],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/entity-name-many/snapshots/4-Babel-Tokens.shot b/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/entity-name-many/snapshots/4-Babel-Tokens.shot
new file mode 100644
index 000000000000..08ed3e892d54
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/entity-name-many/snapshots/4-Babel-Tokens.shot
@@ -0,0 +1,96 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSImportEqualsDeclaration entity-name-many Babel - Tokens 1`] = `
+Array [
+  Keyword {
+    type: "Keyword",
+    value: "import",
+
+    range: [0, 6],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 6, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "F",
+
+    range: [7, 8],
+    loc: {
+      start: { column: 7, line: 1 },
+      end: { column: 8, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "=",
+
+    range: [9, 10],
+    loc: {
+      start: { column: 9, line: 1 },
+      end: { column: 10, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "A",
+
+    range: [11, 12],
+    loc: {
+      start: { column: 11, line: 1 },
+      end: { column: 12, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ".",
+
+    range: [12, 13],
+    loc: {
+      start: { column: 12, line: 1 },
+      end: { column: 13, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "B",
+
+    range: [13, 14],
+    loc: {
+      start: { column: 13, line: 1 },
+      end: { column: 14, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ".",
+
+    range: [14, 15],
+    loc: {
+      start: { column: 14, line: 1 },
+      end: { column: 15, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "C",
+
+    range: [15, 16],
+    loc: {
+      start: { column: 15, line: 1 },
+      end: { column: 16, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ";",
+
+    range: [16, 17],
+    loc: {
+      start: { column: 16, line: 1 },
+      end: { column: 17, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/entity-name-many/snapshots/5-AST-Alignment-AST.shot b/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/entity-name-many/snapshots/5-AST-Alignment-AST.shot
new file mode 100644
index 000000000000..88ec007b237d
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/entity-name-many/snapshots/5-AST-Alignment-AST.shot
@@ -0,0 +1,6 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSImportEqualsDeclaration entity-name-many AST Alignment - AST 1`] = `
+"Snapshot Diff:
+Compared values have no visual difference."
+`;
diff --git a/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/entity-name-many/snapshots/6-AST-Alignment-Tokens.shot b/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/entity-name-many/snapshots/6-AST-Alignment-Tokens.shot
new file mode 100644
index 000000000000..b006c4e07d24
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/entity-name-many/snapshots/6-AST-Alignment-Tokens.shot
@@ -0,0 +1,6 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSImportEqualsDeclaration entity-name-many AST Alignment - Token 1`] = `
+"Snapshot Diff:
+Compared values have no visual difference."
+`;
diff --git a/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/entity-name-one/fixture.ts b/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/entity-name-one/fixture.ts
new file mode 100644
index 000000000000..ac623ee9e280
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/entity-name-one/fixture.ts
@@ -0,0 +1 @@
+import F = A;
diff --git a/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/entity-name-one/snapshots/1-TSESTree-AST.shot b/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/entity-name-one/snapshots/1-TSESTree-AST.shot
new file mode 100644
index 000000000000..aa18656723b0
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/entity-name-one/snapshots/1-TSESTree-AST.shot
@@ -0,0 +1,47 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSImportEqualsDeclaration entity-name-one TSESTree - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    TSImportEqualsDeclaration {
+      type: "TSImportEqualsDeclaration",
+      id: Identifier {
+        type: "Identifier",
+        name: "F",
+
+        range: [7, 8],
+        loc: {
+          start: { column: 7, line: 1 },
+          end: { column: 8, line: 1 },
+        },
+      },
+      importKind: "value",
+      isExport: false,
+      moduleReference: Identifier {
+        type: "Identifier",
+        name: "A",
+
+        range: [11, 12],
+        loc: {
+          start: { column: 11, line: 1 },
+          end: { column: 12, line: 1 },
+        },
+      },
+
+      range: [0, 13],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 13, line: 1 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 14],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/entity-name-one/snapshots/2-TSESTree-Tokens.shot b/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/entity-name-one/snapshots/2-TSESTree-Tokens.shot
new file mode 100644
index 000000000000..1e7f3ae9a452
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/entity-name-one/snapshots/2-TSESTree-Tokens.shot
@@ -0,0 +1,56 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSImportEqualsDeclaration entity-name-one TSESTree - Tokens 1`] = `
+Array [
+  Keyword {
+    type: "Keyword",
+    value: "import",
+
+    range: [0, 6],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 6, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "F",
+
+    range: [7, 8],
+    loc: {
+      start: { column: 7, line: 1 },
+      end: { column: 8, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "=",
+
+    range: [9, 10],
+    loc: {
+      start: { column: 9, line: 1 },
+      end: { column: 10, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "A",
+
+    range: [11, 12],
+    loc: {
+      start: { column: 11, line: 1 },
+      end: { column: 12, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ";",
+
+    range: [12, 13],
+    loc: {
+      start: { column: 12, line: 1 },
+      end: { column: 13, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/entity-name-one/snapshots/3-Babel-AST.shot b/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/entity-name-one/snapshots/3-Babel-AST.shot
new file mode 100644
index 000000000000..d6e2ea9ed203
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/entity-name-one/snapshots/3-Babel-AST.shot
@@ -0,0 +1,47 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSImportEqualsDeclaration entity-name-one Babel - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    TSImportEqualsDeclaration {
+      type: "TSImportEqualsDeclaration",
+      id: Identifier {
+        type: "Identifier",
+        name: "F",
+
+        range: [7, 8],
+        loc: {
+          start: { column: 7, line: 1 },
+          end: { column: 8, line: 1 },
+        },
+      },
+      importKind: "value",
+      isExport: false,
+      moduleReference: Identifier {
+        type: "Identifier",
+        name: "A",
+
+        range: [11, 12],
+        loc: {
+          start: { column: 11, line: 1 },
+          end: { column: 12, line: 1 },
+        },
+      },
+
+      range: [0, 13],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 13, line: 1 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 14],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/entity-name-one/snapshots/4-Babel-Tokens.shot b/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/entity-name-one/snapshots/4-Babel-Tokens.shot
new file mode 100644
index 000000000000..85b199a73a43
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/entity-name-one/snapshots/4-Babel-Tokens.shot
@@ -0,0 +1,56 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSImportEqualsDeclaration entity-name-one Babel - Tokens 1`] = `
+Array [
+  Keyword {
+    type: "Keyword",
+    value: "import",
+
+    range: [0, 6],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 6, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "F",
+
+    range: [7, 8],
+    loc: {
+      start: { column: 7, line: 1 },
+      end: { column: 8, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "=",
+
+    range: [9, 10],
+    loc: {
+      start: { column: 9, line: 1 },
+      end: { column: 10, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "A",
+
+    range: [11, 12],
+    loc: {
+      start: { column: 11, line: 1 },
+      end: { column: 12, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ";",
+
+    range: [12, 13],
+    loc: {
+      start: { column: 12, line: 1 },
+      end: { column: 13, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/entity-name-one/snapshots/5-AST-Alignment-AST.shot b/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/entity-name-one/snapshots/5-AST-Alignment-AST.shot
new file mode 100644
index 000000000000..0cb17969d4fb
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/entity-name-one/snapshots/5-AST-Alignment-AST.shot
@@ -0,0 +1,6 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSImportEqualsDeclaration entity-name-one AST Alignment - AST 1`] = `
+"Snapshot Diff:
+Compared values have no visual difference."
+`;
diff --git a/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/entity-name-one/snapshots/6-AST-Alignment-Tokens.shot b/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/entity-name-one/snapshots/6-AST-Alignment-Tokens.shot
new file mode 100644
index 000000000000..28d07eeb4739
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/entity-name-one/snapshots/6-AST-Alignment-Tokens.shot
@@ -0,0 +1,6 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSImportEqualsDeclaration entity-name-one AST Alignment - Token 1`] = `
+"Snapshot Diff:
+Compared values have no visual difference."
+`;
diff --git a/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/external-module-ref-string/fixture.ts b/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/external-module-ref-string/fixture.ts
new file mode 100644
index 000000000000..2c8ef7abf25c
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/external-module-ref-string/fixture.ts
@@ -0,0 +1 @@
+import F = require('mod');
diff --git a/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/external-module-ref-string/snapshots/1-TSESTree-AST.shot b/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/external-module-ref-string/snapshots/1-TSESTree-AST.shot
new file mode 100644
index 000000000000..aca9d9ab5f3c
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/external-module-ref-string/snapshots/1-TSESTree-AST.shot
@@ -0,0 +1,57 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSImportEqualsDeclaration external-module-ref-string TSESTree - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    TSImportEqualsDeclaration {
+      type: "TSImportEqualsDeclaration",
+      id: Identifier {
+        type: "Identifier",
+        name: "F",
+
+        range: [7, 8],
+        loc: {
+          start: { column: 7, line: 1 },
+          end: { column: 8, line: 1 },
+        },
+      },
+      importKind: "value",
+      isExport: false,
+      moduleReference: TSExternalModuleReference {
+        type: "TSExternalModuleReference",
+        expression: Literal {
+          type: "Literal",
+          raw: "'mod'",
+          value: "mod",
+
+          range: [19, 24],
+          loc: {
+            start: { column: 19, line: 1 },
+            end: { column: 24, line: 1 },
+          },
+        },
+
+        range: [11, 25],
+        loc: {
+          start: { column: 11, line: 1 },
+          end: { column: 25, line: 1 },
+        },
+      },
+
+      range: [0, 26],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 26, line: 1 },
+      },
+    },
+  ],
+  sourceType: "module",
+
+  range: [0, 27],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/external-module-ref-string/snapshots/2-TSESTree-Tokens.shot b/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/external-module-ref-string/snapshots/2-TSESTree-Tokens.shot
new file mode 100644
index 000000000000..023028ef7d99
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/external-module-ref-string/snapshots/2-TSESTree-Tokens.shot
@@ -0,0 +1,86 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSImportEqualsDeclaration external-module-ref-string TSESTree - Tokens 1`] = `
+Array [
+  Keyword {
+    type: "Keyword",
+    value: "import",
+
+    range: [0, 6],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 6, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "F",
+
+    range: [7, 8],
+    loc: {
+      start: { column: 7, line: 1 },
+      end: { column: 8, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "=",
+
+    range: [9, 10],
+    loc: {
+      start: { column: 9, line: 1 },
+      end: { column: 10, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "require",
+
+    range: [11, 18],
+    loc: {
+      start: { column: 11, line: 1 },
+      end: { column: 18, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "(",
+
+    range: [18, 19],
+    loc: {
+      start: { column: 18, line: 1 },
+      end: { column: 19, line: 1 },
+    },
+  },
+  String {
+    type: "String",
+    value: "'mod'",
+
+    range: [19, 24],
+    loc: {
+      start: { column: 19, line: 1 },
+      end: { column: 24, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ")",
+
+    range: [24, 25],
+    loc: {
+      start: { column: 24, line: 1 },
+      end: { column: 25, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ";",
+
+    range: [25, 26],
+    loc: {
+      start: { column: 25, line: 1 },
+      end: { column: 26, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/external-module-ref-string/snapshots/3-Babel-AST.shot b/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/external-module-ref-string/snapshots/3-Babel-AST.shot
new file mode 100644
index 000000000000..f904ff1dbcff
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/external-module-ref-string/snapshots/3-Babel-AST.shot
@@ -0,0 +1,57 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSImportEqualsDeclaration external-module-ref-string Babel - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    TSImportEqualsDeclaration {
+      type: "TSImportEqualsDeclaration",
+      id: Identifier {
+        type: "Identifier",
+        name: "F",
+
+        range: [7, 8],
+        loc: {
+          start: { column: 7, line: 1 },
+          end: { column: 8, line: 1 },
+        },
+      },
+      importKind: "value",
+      isExport: false,
+      moduleReference: TSExternalModuleReference {
+        type: "TSExternalModuleReference",
+        expression: Literal {
+          type: "Literal",
+          raw: "'mod'",
+          value: "mod",
+
+          range: [19, 24],
+          loc: {
+            start: { column: 19, line: 1 },
+            end: { column: 24, line: 1 },
+          },
+        },
+
+        range: [11, 25],
+        loc: {
+          start: { column: 11, line: 1 },
+          end: { column: 25, line: 1 },
+        },
+      },
+
+      range: [0, 26],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 26, line: 1 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 27],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/external-module-ref-string/snapshots/4-Babel-Tokens.shot b/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/external-module-ref-string/snapshots/4-Babel-Tokens.shot
new file mode 100644
index 000000000000..91b65568fbec
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/external-module-ref-string/snapshots/4-Babel-Tokens.shot
@@ -0,0 +1,86 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSImportEqualsDeclaration external-module-ref-string Babel - Tokens 1`] = `
+Array [
+  Keyword {
+    type: "Keyword",
+    value: "import",
+
+    range: [0, 6],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 6, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "F",
+
+    range: [7, 8],
+    loc: {
+      start: { column: 7, line: 1 },
+      end: { column: 8, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "=",
+
+    range: [9, 10],
+    loc: {
+      start: { column: 9, line: 1 },
+      end: { column: 10, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "require",
+
+    range: [11, 18],
+    loc: {
+      start: { column: 11, line: 1 },
+      end: { column: 18, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "(",
+
+    range: [18, 19],
+    loc: {
+      start: { column: 18, line: 1 },
+      end: { column: 19, line: 1 },
+    },
+  },
+  String {
+    type: "String",
+    value: "'mod'",
+
+    range: [19, 24],
+    loc: {
+      start: { column: 19, line: 1 },
+      end: { column: 24, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ")",
+
+    range: [24, 25],
+    loc: {
+      start: { column: 24, line: 1 },
+      end: { column: 25, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ";",
+
+    range: [25, 26],
+    loc: {
+      start: { column: 25, line: 1 },
+      end: { column: 26, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/external-module-ref-string/snapshots/5-AST-Alignment-AST.shot b/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/external-module-ref-string/snapshots/5-AST-Alignment-AST.shot
new file mode 100644
index 000000000000..a0b231ec7a17
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/external-module-ref-string/snapshots/5-AST-Alignment-AST.shot
@@ -0,0 +1,62 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSImportEqualsDeclaration external-module-ref-string AST Alignment - AST 1`] = `
+"Snapshot Diff:
+- TSESTree
++ Babel
+
+  Program {
+    type: 'Program',
+    body: Array [
+      TSImportEqualsDeclaration {
+        type: 'TSImportEqualsDeclaration',
+        id: Identifier {
+          type: 'Identifier',
+          name: 'F',
+
+          range: [7, 8],
+          loc: {
+            start: { column: 7, line: 1 },
+            end: { column: 8, line: 1 },
+          },
+        },
+        importKind: 'value',
+        isExport: false,
+        moduleReference: TSExternalModuleReference {
+          type: 'TSExternalModuleReference',
+          expression: Literal {
+            type: 'Literal',
+            raw: '\\\\'mod\\\\'',
+            value: 'mod',
+
+            range: [19, 24],
+            loc: {
+              start: { column: 19, line: 1 },
+              end: { column: 24, line: 1 },
+            },
+          },
+
+          range: [11, 25],
+          loc: {
+            start: { column: 11, line: 1 },
+            end: { column: 25, line: 1 },
+          },
+        },
+
+        range: [0, 26],
+        loc: {
+          start: { column: 0, line: 1 },
+          end: { column: 26, line: 1 },
+        },
+      },
+    ],
+-   sourceType: 'module',
++   sourceType: 'script',
+
+    range: [0, 27],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 0, line: 2 },
+    },
+  }"
+`;
diff --git a/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/external-module-ref-string/snapshots/6-AST-Alignment-Tokens.shot b/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/external-module-ref-string/snapshots/6-AST-Alignment-Tokens.shot
new file mode 100644
index 000000000000..ce5e5680101a
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/fixtures/external-module-ref-string/snapshots/6-AST-Alignment-Tokens.shot
@@ -0,0 +1,6 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSImportEqualsDeclaration external-module-ref-string AST Alignment - Token 1`] = `
+"Snapshot Diff:
+Compared values have no visual difference."
+`;
diff --git a/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/spec.ts b/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/spec.ts
index 5ccd9b6fc4fc..d4db9a64168b 100644
--- a/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/spec.ts
+++ b/packages/ast-spec/src/declaration/TSImportEqualsDeclaration/spec.ts
@@ -7,8 +7,27 @@ import type { ImportKind } from '../ExportAndImportKind';
 
 export interface TSImportEqualsDeclaration extends BaseNode {
   type: AST_NODE_TYPES.TSImportEqualsDeclaration;
+  /**
+   * The locally imported name
+   */
   id: Identifier;
+  /**
+   * The value being aliased.
+   * ```
+   * import F1 = A;
+   * import F2 = A.B.C;
+   * import F3 = require('mod');
+   * ```
+   */
   moduleReference: EntityName | TSExternalModuleReference;
+  // TODO(#1852) - breaking change remove this as it is invalid
   importKind: ImportKind;
+  /**
+   * Whether this is immediately exported
+   * ```
+   * export import F = A;
+   * ```
+   */
+  // TODO(#4130) - this should be represented in the AST
   isExport: boolean;
 }
diff --git a/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/_error_/missing-body/fixture.ts b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/_error_/missing-body/fixture.ts
new file mode 100644
index 000000000000..b3123630664e
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/_error_/missing-body/fixture.ts
@@ -0,0 +1 @@
+interface F;
diff --git a/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/_error_/missing-body/snapshots/1-TSESTree-Error.shot b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/_error_/missing-body/snapshots/1-TSESTree-Error.shot
new file mode 100644
index 000000000000..128274dff580
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/_error_/missing-body/snapshots/1-TSESTree-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSInterfaceDeclaration _error_ missing-body TSESTree - Error 1`] = `[TSError: '{' expected.]`;
diff --git a/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/_error_/missing-body/snapshots/2-Babel-Error.shot b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/_error_/missing-body/snapshots/2-Babel-Error.shot
new file mode 100644
index 000000000000..12baf6e07385
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/_error_/missing-body/snapshots/2-Babel-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSInterfaceDeclaration _error_ missing-body Babel - Error 1`] = `[SyntaxError: Unexpected token, expected "{" (1:11)]`;
diff --git a/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/_error_/missing-body/snapshots/3-Alignment-Error.shot b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/_error_/missing-body/snapshots/3-Alignment-Error.shot
new file mode 100644
index 000000000000..6caba1ae72c9
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/_error_/missing-body/snapshots/3-Alignment-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSInterfaceDeclaration _error_ missing-body Error Alignment 1`] = `"Both errored"`;
diff --git a/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/_error_/missing-extends/fixture.ts b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/_error_/missing-extends/fixture.ts
new file mode 100644
index 000000000000..74fde08aea13
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/_error_/missing-extends/fixture.ts
@@ -0,0 +1 @@
+interface F extends {}
diff --git a/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/_error_/missing-extends/snapshots/1-TSESTree-Error.shot b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/_error_/missing-extends/snapshots/1-TSESTree-Error.shot
new file mode 100644
index 000000000000..a33eb58a06d4
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/_error_/missing-extends/snapshots/1-TSESTree-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSInterfaceDeclaration _error_ missing-extends TSESTree - Error 1`] = `"NO ERROR"`;
diff --git a/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/_error_/missing-extends/snapshots/2-Babel-Error.shot b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/_error_/missing-extends/snapshots/2-Babel-Error.shot
new file mode 100644
index 000000000000..add92930a37f
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/_error_/missing-extends/snapshots/2-Babel-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSInterfaceDeclaration _error_ missing-extends Babel - Error 1`] = `[SyntaxError: 'extends' list cannot be empty. (1:20)]`;
diff --git a/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/_error_/missing-extends/snapshots/3-Alignment-Error.shot b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/_error_/missing-extends/snapshots/3-Alignment-Error.shot
new file mode 100644
index 000000000000..6eb1bf9104f9
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/_error_/missing-extends/snapshots/3-Alignment-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSInterfaceDeclaration _error_ missing-extends Error Alignment 1`] = `"Babel errored but TSESTree didn't"`;
diff --git a/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/_error_/missing-id/fixture.ts b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/_error_/missing-id/fixture.ts
new file mode 100644
index 000000000000..6b562c272fc7
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/_error_/missing-id/fixture.ts
@@ -0,0 +1 @@
+interface {}
diff --git a/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/_error_/missing-id/snapshots/1-TSESTree-Error.shot b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/_error_/missing-id/snapshots/1-TSESTree-Error.shot
new file mode 100644
index 000000000000..d640ad78d536
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/_error_/missing-id/snapshots/1-TSESTree-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSInterfaceDeclaration _error_ missing-id TSESTree - Error 1`] = `[TSError: Interface must be given a name.]`;
diff --git a/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/_error_/missing-id/snapshots/2-Babel-Error.shot b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/_error_/missing-id/snapshots/2-Babel-Error.shot
new file mode 100644
index 000000000000..e06bfcc1a1c5
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/_error_/missing-id/snapshots/2-Babel-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSInterfaceDeclaration _error_ missing-id Babel - Error 1`] = `[SyntaxError: 'interface' declarations must be followed by an identifier. (1:10)]`;
diff --git a/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/_error_/missing-id/snapshots/3-Alignment-Error.shot b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/_error_/missing-id/snapshots/3-Alignment-Error.shot
new file mode 100644
index 000000000000..bbce8c51c4d4
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/_error_/missing-id/snapshots/3-Alignment-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSInterfaceDeclaration _error_ missing-id Error Alignment 1`] = `"Both errored"`;
diff --git a/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/_error_/missing-type-param/fixture.ts b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/_error_/missing-type-param/fixture.ts
new file mode 100644
index 000000000000..f03a31c78c2e
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/_error_/missing-type-param/fixture.ts
@@ -0,0 +1 @@
+interface F<> {}
diff --git a/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/_error_/missing-type-param/snapshots/1-TSESTree-Error.shot b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/_error_/missing-type-param/snapshots/1-TSESTree-Error.shot
new file mode 100644
index 000000000000..9d0be0712d44
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/_error_/missing-type-param/snapshots/1-TSESTree-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSInterfaceDeclaration _error_ missing-type-param TSESTree - Error 1`] = `"NO ERROR"`;
diff --git a/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/_error_/missing-type-param/snapshots/2-Babel-Error.shot b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/_error_/missing-type-param/snapshots/2-Babel-Error.shot
new file mode 100644
index 000000000000..936edbec8c8a
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/_error_/missing-type-param/snapshots/2-Babel-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSInterfaceDeclaration _error_ missing-type-param Babel - Error 1`] = `[SyntaxError: Type parameter list cannot be empty. (1:11)]`;
diff --git a/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/_error_/missing-type-param/snapshots/3-Alignment-Error.shot b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/_error_/missing-type-param/snapshots/3-Alignment-Error.shot
new file mode 100644
index 000000000000..5846179dd56b
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/_error_/missing-type-param/snapshots/3-Alignment-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSInterfaceDeclaration _error_ missing-type-param Error Alignment 1`] = `"Babel errored but TSESTree didn't"`;
diff --git a/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/_error_/non-identifier-extends/fixture.ts b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/_error_/non-identifier-extends/fixture.ts
new file mode 100644
index 000000000000..c649bd496622
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/_error_/non-identifier-extends/fixture.ts
@@ -0,0 +1 @@
+interface F extends 1 {}
diff --git a/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/_error_/non-identifier-extends/snapshots/1-TSESTree-Error.shot b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/_error_/non-identifier-extends/snapshots/1-TSESTree-Error.shot
new file mode 100644
index 000000000000..e8e8c0e5fdb9
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/_error_/non-identifier-extends/snapshots/1-TSESTree-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSInterfaceDeclaration _error_ non-identifier-extends TSESTree - Error 1`] = `"NO ERROR"`;
diff --git a/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/_error_/non-identifier-extends/snapshots/2-Babel-Error.shot b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/_error_/non-identifier-extends/snapshots/2-Babel-Error.shot
new file mode 100644
index 000000000000..e7b584a9cd2e
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/_error_/non-identifier-extends/snapshots/2-Babel-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSInterfaceDeclaration _error_ non-identifier-extends Babel - Error 1`] = `[SyntaxError: Unexpected token (1:20)]`;
diff --git a/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/_error_/non-identifier-extends/snapshots/3-Alignment-Error.shot b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/_error_/non-identifier-extends/snapshots/3-Alignment-Error.shot
new file mode 100644
index 000000000000..c429168c2884
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/_error_/non-identifier-extends/snapshots/3-Alignment-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSInterfaceDeclaration _error_ non-identifier-extends Error Alignment 1`] = `"Babel errored but TSESTree didn't"`;
diff --git a/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/_error_/non-identifier-name/fixture.ts b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/_error_/non-identifier-name/fixture.ts
new file mode 100644
index 000000000000..7b8c5e961eed
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/_error_/non-identifier-name/fixture.ts
@@ -0,0 +1 @@
+interface 1 {}
diff --git a/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/_error_/non-identifier-name/snapshots/1-TSESTree-Error.shot b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/_error_/non-identifier-name/snapshots/1-TSESTree-Error.shot
new file mode 100644
index 000000000000..7b6a2f0a6669
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/_error_/non-identifier-name/snapshots/1-TSESTree-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSInterfaceDeclaration _error_ non-identifier-name TSESTree - Error 1`] = `[TSError: Interface name cannot be '1'.]`;
diff --git a/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/_error_/non-identifier-name/snapshots/2-Babel-Error.shot b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/_error_/non-identifier-name/snapshots/2-Babel-Error.shot
new file mode 100644
index 000000000000..64f544addb3b
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/_error_/non-identifier-name/snapshots/2-Babel-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSInterfaceDeclaration _error_ non-identifier-name Babel - Error 1`] = `[SyntaxError: 'interface' declarations must be followed by an identifier. (1:10)]`;
diff --git a/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/_error_/non-identifier-name/snapshots/3-Alignment-Error.shot b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/_error_/non-identifier-name/snapshots/3-Alignment-Error.shot
new file mode 100644
index 000000000000..5470a1ec04e8
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/_error_/non-identifier-name/snapshots/3-Alignment-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSInterfaceDeclaration _error_ non-identifier-name Error Alignment 1`] = `"Both errored"`;
diff --git a/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/_error_/non-identifier-type-param/fixture.ts b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/_error_/non-identifier-type-param/fixture.ts
new file mode 100644
index 000000000000..2809a08b8cf2
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/_error_/non-identifier-type-param/fixture.ts
@@ -0,0 +1 @@
+interface F<1> {}
diff --git a/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/_error_/non-identifier-type-param/snapshots/1-TSESTree-Error.shot b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/_error_/non-identifier-type-param/snapshots/1-TSESTree-Error.shot
new file mode 100644
index 000000000000..e48629574cff
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/_error_/non-identifier-type-param/snapshots/1-TSESTree-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSInterfaceDeclaration _error_ non-identifier-type-param TSESTree - Error 1`] = `[TSError: Type parameter declaration expected.]`;
diff --git a/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/_error_/non-identifier-type-param/snapshots/2-Babel-Error.shot b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/_error_/non-identifier-type-param/snapshots/2-Babel-Error.shot
new file mode 100644
index 000000000000..69166a9fa112
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/_error_/non-identifier-type-param/snapshots/2-Babel-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSInterfaceDeclaration _error_ non-identifier-type-param Babel - Error 1`] = `[SyntaxError: Unexpected token (1:12)]`;
diff --git a/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/_error_/non-identifier-type-param/snapshots/3-Alignment-Error.shot b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/_error_/non-identifier-type-param/snapshots/3-Alignment-Error.shot
new file mode 100644
index 000000000000..5f1be010c628
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/_error_/non-identifier-type-param/snapshots/3-Alignment-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSInterfaceDeclaration _error_ non-identifier-type-param Error Alignment 1`] = `"Both errored"`;
diff --git a/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/declare/fixture.ts b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/declare/fixture.ts
new file mode 100644
index 000000000000..0e8aa5a34797
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/declare/fixture.ts
@@ -0,0 +1 @@
+declare interface F {}
diff --git a/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/declare/snapshots/1-TSESTree-AST.shot b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/declare/snapshots/1-TSESTree-AST.shot
new file mode 100644
index 000000000000..501d609a46c6
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/declare/snapshots/1-TSESTree-AST.shot
@@ -0,0 +1,46 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSInterfaceDeclaration declare TSESTree - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    TSInterfaceDeclaration {
+      type: "TSInterfaceDeclaration",
+      body: TSInterfaceBody {
+        type: "TSInterfaceBody",
+        body: Array [],
+
+        range: [20, 22],
+        loc: {
+          start: { column: 20, line: 1 },
+          end: { column: 22, line: 1 },
+        },
+      },
+      declare: true,
+      id: Identifier {
+        type: "Identifier",
+        name: "F",
+
+        range: [18, 19],
+        loc: {
+          start: { column: 18, line: 1 },
+          end: { column: 19, line: 1 },
+        },
+      },
+
+      range: [0, 22],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 22, line: 1 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 23],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/declare/snapshots/2-TSESTree-Tokens.shot b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/declare/snapshots/2-TSESTree-Tokens.shot
new file mode 100644
index 000000000000..8899a66c8a3d
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/declare/snapshots/2-TSESTree-Tokens.shot
@@ -0,0 +1,56 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSInterfaceDeclaration declare TSESTree - Tokens 1`] = `
+Array [
+  Identifier {
+    type: "Identifier",
+    value: "declare",
+
+    range: [0, 7],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 7, line: 1 },
+    },
+  },
+  Keyword {
+    type: "Keyword",
+    value: "interface",
+
+    range: [8, 17],
+    loc: {
+      start: { column: 8, line: 1 },
+      end: { column: 17, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "F",
+
+    range: [18, 19],
+    loc: {
+      start: { column: 18, line: 1 },
+      end: { column: 19, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "{",
+
+    range: [20, 21],
+    loc: {
+      start: { column: 20, line: 1 },
+      end: { column: 21, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "}",
+
+    range: [21, 22],
+    loc: {
+      start: { column: 21, line: 1 },
+      end: { column: 22, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/declare/snapshots/3-Babel-AST.shot b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/declare/snapshots/3-Babel-AST.shot
new file mode 100644
index 000000000000..4642a30ee6d6
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/declare/snapshots/3-Babel-AST.shot
@@ -0,0 +1,46 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSInterfaceDeclaration declare Babel - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    TSInterfaceDeclaration {
+      type: "TSInterfaceDeclaration",
+      body: TSInterfaceBody {
+        type: "TSInterfaceBody",
+        body: Array [],
+
+        range: [20, 22],
+        loc: {
+          start: { column: 20, line: 1 },
+          end: { column: 22, line: 1 },
+        },
+      },
+      declare: true,
+      id: Identifier {
+        type: "Identifier",
+        name: "F",
+
+        range: [18, 19],
+        loc: {
+          start: { column: 18, line: 1 },
+          end: { column: 19, line: 1 },
+        },
+      },
+
+      range: [0, 22],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 22, line: 1 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 23],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/declare/snapshots/4-Babel-Tokens.shot b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/declare/snapshots/4-Babel-Tokens.shot
new file mode 100644
index 000000000000..b75639c632d9
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/declare/snapshots/4-Babel-Tokens.shot
@@ -0,0 +1,56 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSInterfaceDeclaration declare Babel - Tokens 1`] = `
+Array [
+  Identifier {
+    type: "Identifier",
+    value: "declare",
+
+    range: [0, 7],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 7, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "interface",
+
+    range: [8, 17],
+    loc: {
+      start: { column: 8, line: 1 },
+      end: { column: 17, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "F",
+
+    range: [18, 19],
+    loc: {
+      start: { column: 18, line: 1 },
+      end: { column: 19, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "{",
+
+    range: [20, 21],
+    loc: {
+      start: { column: 20, line: 1 },
+      end: { column: 21, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "}",
+
+    range: [21, 22],
+    loc: {
+      start: { column: 21, line: 1 },
+      end: { column: 22, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/declare/snapshots/5-AST-Alignment-AST.shot b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/declare/snapshots/5-AST-Alignment-AST.shot
new file mode 100644
index 000000000000..c5bfaba693bb
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/declare/snapshots/5-AST-Alignment-AST.shot
@@ -0,0 +1,6 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSInterfaceDeclaration declare AST Alignment - AST 1`] = `
+"Snapshot Diff:
+Compared values have no visual difference."
+`;
diff --git a/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/declare/snapshots/6-AST-Alignment-Tokens.shot b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/declare/snapshots/6-AST-Alignment-Tokens.shot
new file mode 100644
index 000000000000..057cff335273
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/declare/snapshots/6-AST-Alignment-Tokens.shot
@@ -0,0 +1,62 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSInterfaceDeclaration declare AST Alignment - Token 1`] = `
+"Snapshot Diff:
+- TSESTree
++ Babel
+
+  Array [
+    Identifier {
+      type: 'Identifier',
+      value: 'declare',
+
+      range: [0, 7],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 7, line: 1 },
+      },
+    },
+-   Keyword {
+-     type: 'Keyword',
++   Identifier {
++     type: 'Identifier',
+      value: 'interface',
+
+      range: [8, 17],
+      loc: {
+        start: { column: 8, line: 1 },
+        end: { column: 17, line: 1 },
+      },
+    },
+    Identifier {
+      type: 'Identifier',
+      value: 'F',
+
+      range: [18, 19],
+      loc: {
+        start: { column: 18, line: 1 },
+        end: { column: 19, line: 1 },
+      },
+    },
+    Punctuator {
+      type: 'Punctuator',
+      value: '{',
+
+      range: [20, 21],
+      loc: {
+        start: { column: 20, line: 1 },
+        end: { column: 21, line: 1 },
+      },
+    },
+    Punctuator {
+      type: 'Punctuator',
+      value: '}',
+
+      range: [21, 22],
+      loc: {
+        start: { column: 21, line: 1 },
+        end: { column: 22, line: 1 },
+      },
+    },
+  ]"
+`;
diff --git a/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/empty/fixture.ts b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/empty/fixture.ts
new file mode 100644
index 000000000000..296dc32043fa
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/empty/fixture.ts
@@ -0,0 +1 @@
+interface F {}
diff --git a/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/empty/snapshots/1-TSESTree-AST.shot b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/empty/snapshots/1-TSESTree-AST.shot
new file mode 100644
index 000000000000..aa7db3176924
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/empty/snapshots/1-TSESTree-AST.shot
@@ -0,0 +1,45 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSInterfaceDeclaration empty TSESTree - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    TSInterfaceDeclaration {
+      type: "TSInterfaceDeclaration",
+      body: TSInterfaceBody {
+        type: "TSInterfaceBody",
+        body: Array [],
+
+        range: [12, 14],
+        loc: {
+          start: { column: 12, line: 1 },
+          end: { column: 14, line: 1 },
+        },
+      },
+      id: Identifier {
+        type: "Identifier",
+        name: "F",
+
+        range: [10, 11],
+        loc: {
+          start: { column: 10, line: 1 },
+          end: { column: 11, line: 1 },
+        },
+      },
+
+      range: [0, 14],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 14, line: 1 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 15],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/empty/snapshots/2-TSESTree-Tokens.shot b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/empty/snapshots/2-TSESTree-Tokens.shot
new file mode 100644
index 000000000000..b46401c81876
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/empty/snapshots/2-TSESTree-Tokens.shot
@@ -0,0 +1,46 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSInterfaceDeclaration empty TSESTree - Tokens 1`] = `
+Array [
+  Keyword {
+    type: "Keyword",
+    value: "interface",
+
+    range: [0, 9],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 9, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "F",
+
+    range: [10, 11],
+    loc: {
+      start: { column: 10, line: 1 },
+      end: { column: 11, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "{",
+
+    range: [12, 13],
+    loc: {
+      start: { column: 12, line: 1 },
+      end: { column: 13, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "}",
+
+    range: [13, 14],
+    loc: {
+      start: { column: 13, line: 1 },
+      end: { column: 14, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/empty/snapshots/3-Babel-AST.shot b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/empty/snapshots/3-Babel-AST.shot
new file mode 100644
index 000000000000..e6048d6bde46
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/empty/snapshots/3-Babel-AST.shot
@@ -0,0 +1,45 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSInterfaceDeclaration empty Babel - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    TSInterfaceDeclaration {
+      type: "TSInterfaceDeclaration",
+      body: TSInterfaceBody {
+        type: "TSInterfaceBody",
+        body: Array [],
+
+        range: [12, 14],
+        loc: {
+          start: { column: 12, line: 1 },
+          end: { column: 14, line: 1 },
+        },
+      },
+      id: Identifier {
+        type: "Identifier",
+        name: "F",
+
+        range: [10, 11],
+        loc: {
+          start: { column: 10, line: 1 },
+          end: { column: 11, line: 1 },
+        },
+      },
+
+      range: [0, 14],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 14, line: 1 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 15],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/empty/snapshots/4-Babel-Tokens.shot b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/empty/snapshots/4-Babel-Tokens.shot
new file mode 100644
index 000000000000..01311e4df0ca
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/empty/snapshots/4-Babel-Tokens.shot
@@ -0,0 +1,46 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSInterfaceDeclaration empty Babel - Tokens 1`] = `
+Array [
+  Identifier {
+    type: "Identifier",
+    value: "interface",
+
+    range: [0, 9],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 9, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "F",
+
+    range: [10, 11],
+    loc: {
+      start: { column: 10, line: 1 },
+      end: { column: 11, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "{",
+
+    range: [12, 13],
+    loc: {
+      start: { column: 12, line: 1 },
+      end: { column: 13, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "}",
+
+    range: [13, 14],
+    loc: {
+      start: { column: 13, line: 1 },
+      end: { column: 14, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/empty/snapshots/5-AST-Alignment-AST.shot b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/empty/snapshots/5-AST-Alignment-AST.shot
new file mode 100644
index 000000000000..42bc3c4eb68c
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/empty/snapshots/5-AST-Alignment-AST.shot
@@ -0,0 +1,6 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSInterfaceDeclaration empty AST Alignment - AST 1`] = `
+"Snapshot Diff:
+Compared values have no visual difference."
+`;
diff --git a/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/empty/snapshots/6-AST-Alignment-Tokens.shot b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/empty/snapshots/6-AST-Alignment-Tokens.shot
new file mode 100644
index 000000000000..68a5be8dd4f8
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/empty/snapshots/6-AST-Alignment-Tokens.shot
@@ -0,0 +1,52 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSInterfaceDeclaration empty AST Alignment - Token 1`] = `
+"Snapshot Diff:
+- TSESTree
++ Babel
+
+  Array [
+-   Keyword {
+-     type: 'Keyword',
++   Identifier {
++     type: 'Identifier',
+      value: 'interface',
+
+      range: [0, 9],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 9, line: 1 },
+      },
+    },
+    Identifier {
+      type: 'Identifier',
+      value: 'F',
+
+      range: [10, 11],
+      loc: {
+        start: { column: 10, line: 1 },
+        end: { column: 11, line: 1 },
+      },
+    },
+    Punctuator {
+      type: 'Punctuator',
+      value: '{',
+
+      range: [12, 13],
+      loc: {
+        start: { column: 12, line: 1 },
+        end: { column: 13, line: 1 },
+      },
+    },
+    Punctuator {
+      type: 'Punctuator',
+      value: '}',
+
+      range: [13, 14],
+      loc: {
+        start: { column: 13, line: 1 },
+        end: { column: 14, line: 1 },
+      },
+    },
+  ]"
+`;
diff --git a/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/extends-many/fixture.ts b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/extends-many/fixture.ts
new file mode 100644
index 000000000000..a0c396132b50
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/extends-many/fixture.ts
@@ -0,0 +1 @@
+interface F extends A, B, C {}
diff --git a/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/extends-many/snapshots/1-TSESTree-AST.shot b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/extends-many/snapshots/1-TSESTree-AST.shot
new file mode 100644
index 000000000000..2e08532845c8
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/extends-many/snapshots/1-TSESTree-AST.shot
@@ -0,0 +1,104 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSInterfaceDeclaration extends-many TSESTree - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    TSInterfaceDeclaration {
+      type: "TSInterfaceDeclaration",
+      body: TSInterfaceBody {
+        type: "TSInterfaceBody",
+        body: Array [],
+
+        range: [28, 30],
+        loc: {
+          start: { column: 28, line: 1 },
+          end: { column: 30, line: 1 },
+        },
+      },
+      extends: Array [
+        TSInterfaceHeritage {
+          type: "TSInterfaceHeritage",
+          expression: Identifier {
+            type: "Identifier",
+            name: "A",
+
+            range: [20, 21],
+            loc: {
+              start: { column: 20, line: 1 },
+              end: { column: 21, line: 1 },
+            },
+          },
+
+          range: [20, 21],
+          loc: {
+            start: { column: 20, line: 1 },
+            end: { column: 21, line: 1 },
+          },
+        },
+        TSInterfaceHeritage {
+          type: "TSInterfaceHeritage",
+          expression: Identifier {
+            type: "Identifier",
+            name: "B",
+
+            range: [23, 24],
+            loc: {
+              start: { column: 23, line: 1 },
+              end: { column: 24, line: 1 },
+            },
+          },
+
+          range: [23, 24],
+          loc: {
+            start: { column: 23, line: 1 },
+            end: { column: 24, line: 1 },
+          },
+        },
+        TSInterfaceHeritage {
+          type: "TSInterfaceHeritage",
+          expression: Identifier {
+            type: "Identifier",
+            name: "C",
+
+            range: [26, 27],
+            loc: {
+              start: { column: 26, line: 1 },
+              end: { column: 27, line: 1 },
+            },
+          },
+
+          range: [26, 27],
+          loc: {
+            start: { column: 26, line: 1 },
+            end: { column: 27, line: 1 },
+          },
+        },
+      ],
+      id: Identifier {
+        type: "Identifier",
+        name: "F",
+
+        range: [10, 11],
+        loc: {
+          start: { column: 10, line: 1 },
+          end: { column: 11, line: 1 },
+        },
+      },
+
+      range: [0, 30],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 30, line: 1 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 31],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/extends-many/snapshots/2-TSESTree-Tokens.shot b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/extends-many/snapshots/2-TSESTree-Tokens.shot
new file mode 100644
index 000000000000..b5418859abc6
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/extends-many/snapshots/2-TSESTree-Tokens.shot
@@ -0,0 +1,106 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSInterfaceDeclaration extends-many TSESTree - Tokens 1`] = `
+Array [
+  Keyword {
+    type: "Keyword",
+    value: "interface",
+
+    range: [0, 9],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 9, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "F",
+
+    range: [10, 11],
+    loc: {
+      start: { column: 10, line: 1 },
+      end: { column: 11, line: 1 },
+    },
+  },
+  Keyword {
+    type: "Keyword",
+    value: "extends",
+
+    range: [12, 19],
+    loc: {
+      start: { column: 12, line: 1 },
+      end: { column: 19, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "A",
+
+    range: [20, 21],
+    loc: {
+      start: { column: 20, line: 1 },
+      end: { column: 21, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ",",
+
+    range: [21, 22],
+    loc: {
+      start: { column: 21, line: 1 },
+      end: { column: 22, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "B",
+
+    range: [23, 24],
+    loc: {
+      start: { column: 23, line: 1 },
+      end: { column: 24, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ",",
+
+    range: [24, 25],
+    loc: {
+      start: { column: 24, line: 1 },
+      end: { column: 25, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "C",
+
+    range: [26, 27],
+    loc: {
+      start: { column: 26, line: 1 },
+      end: { column: 27, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "{",
+
+    range: [28, 29],
+    loc: {
+      start: { column: 28, line: 1 },
+      end: { column: 29, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "}",
+
+    range: [29, 30],
+    loc: {
+      start: { column: 29, line: 1 },
+      end: { column: 30, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/extends-many/snapshots/3-Babel-AST.shot b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/extends-many/snapshots/3-Babel-AST.shot
new file mode 100644
index 000000000000..18e1c620074b
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/extends-many/snapshots/3-Babel-AST.shot
@@ -0,0 +1,104 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSInterfaceDeclaration extends-many Babel - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    TSInterfaceDeclaration {
+      type: "TSInterfaceDeclaration",
+      body: TSInterfaceBody {
+        type: "TSInterfaceBody",
+        body: Array [],
+
+        range: [28, 30],
+        loc: {
+          start: { column: 28, line: 1 },
+          end: { column: 30, line: 1 },
+        },
+      },
+      extends: Array [
+        TSExpressionWithTypeArguments {
+          type: "TSExpressionWithTypeArguments",
+          expression: Identifier {
+            type: "Identifier",
+            name: "A",
+
+            range: [20, 21],
+            loc: {
+              start: { column: 20, line: 1 },
+              end: { column: 21, line: 1 },
+            },
+          },
+
+          range: [20, 21],
+          loc: {
+            start: { column: 20, line: 1 },
+            end: { column: 21, line: 1 },
+          },
+        },
+        TSExpressionWithTypeArguments {
+          type: "TSExpressionWithTypeArguments",
+          expression: Identifier {
+            type: "Identifier",
+            name: "B",
+
+            range: [23, 24],
+            loc: {
+              start: { column: 23, line: 1 },
+              end: { column: 24, line: 1 },
+            },
+          },
+
+          range: [23, 24],
+          loc: {
+            start: { column: 23, line: 1 },
+            end: { column: 24, line: 1 },
+          },
+        },
+        TSExpressionWithTypeArguments {
+          type: "TSExpressionWithTypeArguments",
+          expression: Identifier {
+            type: "Identifier",
+            name: "C",
+
+            range: [26, 27],
+            loc: {
+              start: { column: 26, line: 1 },
+              end: { column: 27, line: 1 },
+            },
+          },
+
+          range: [26, 27],
+          loc: {
+            start: { column: 26, line: 1 },
+            end: { column: 27, line: 1 },
+          },
+        },
+      ],
+      id: Identifier {
+        type: "Identifier",
+        name: "F",
+
+        range: [10, 11],
+        loc: {
+          start: { column: 10, line: 1 },
+          end: { column: 11, line: 1 },
+        },
+      },
+
+      range: [0, 30],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 30, line: 1 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 31],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/extends-many/snapshots/4-Babel-Tokens.shot b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/extends-many/snapshots/4-Babel-Tokens.shot
new file mode 100644
index 000000000000..c6f5129d13f9
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/extends-many/snapshots/4-Babel-Tokens.shot
@@ -0,0 +1,106 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSInterfaceDeclaration extends-many Babel - Tokens 1`] = `
+Array [
+  Identifier {
+    type: "Identifier",
+    value: "interface",
+
+    range: [0, 9],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 9, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "F",
+
+    range: [10, 11],
+    loc: {
+      start: { column: 10, line: 1 },
+      end: { column: 11, line: 1 },
+    },
+  },
+  Keyword {
+    type: "Keyword",
+    value: "extends",
+
+    range: [12, 19],
+    loc: {
+      start: { column: 12, line: 1 },
+      end: { column: 19, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "A",
+
+    range: [20, 21],
+    loc: {
+      start: { column: 20, line: 1 },
+      end: { column: 21, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ",",
+
+    range: [21, 22],
+    loc: {
+      start: { column: 21, line: 1 },
+      end: { column: 22, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "B",
+
+    range: [23, 24],
+    loc: {
+      start: { column: 23, line: 1 },
+      end: { column: 24, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ",",
+
+    range: [24, 25],
+    loc: {
+      start: { column: 24, line: 1 },
+      end: { column: 25, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "C",
+
+    range: [26, 27],
+    loc: {
+      start: { column: 26, line: 1 },
+      end: { column: 27, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "{",
+
+    range: [28, 29],
+    loc: {
+      start: { column: 28, line: 1 },
+      end: { column: 29, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "}",
+
+    range: [29, 30],
+    loc: {
+      start: { column: 29, line: 1 },
+      end: { column: 30, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/extends-many/snapshots/5-AST-Alignment-AST.shot b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/extends-many/snapshots/5-AST-Alignment-AST.shot
new file mode 100644
index 000000000000..793c00b7e980
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/extends-many/snapshots/5-AST-Alignment-AST.shot
@@ -0,0 +1,114 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSInterfaceDeclaration extends-many AST Alignment - AST 1`] = `
+"Snapshot Diff:
+- TSESTree
++ Babel
+
+  Program {
+    type: 'Program',
+    body: Array [
+      TSInterfaceDeclaration {
+        type: 'TSInterfaceDeclaration',
+        body: TSInterfaceBody {
+          type: 'TSInterfaceBody',
+          body: Array [],
+
+          range: [28, 30],
+          loc: {
+            start: { column: 28, line: 1 },
+            end: { column: 30, line: 1 },
+          },
+        },
+        extends: Array [
+-         TSInterfaceHeritage {
+-           type: 'TSInterfaceHeritage',
++         TSExpressionWithTypeArguments {
++           type: 'TSExpressionWithTypeArguments',
+            expression: Identifier {
+              type: 'Identifier',
+              name: 'A',
+
+              range: [20, 21],
+              loc: {
+                start: { column: 20, line: 1 },
+                end: { column: 21, line: 1 },
+              },
+            },
+
+            range: [20, 21],
+            loc: {
+              start: { column: 20, line: 1 },
+              end: { column: 21, line: 1 },
+            },
+          },
+-         TSInterfaceHeritage {
+-           type: 'TSInterfaceHeritage',
++         TSExpressionWithTypeArguments {
++           type: 'TSExpressionWithTypeArguments',
+            expression: Identifier {
+              type: 'Identifier',
+              name: 'B',
+
+              range: [23, 24],
+              loc: {
+                start: { column: 23, line: 1 },
+                end: { column: 24, line: 1 },
+              },
+            },
+
+            range: [23, 24],
+            loc: {
+              start: { column: 23, line: 1 },
+              end: { column: 24, line: 1 },
+            },
+          },
+-         TSInterfaceHeritage {
+-           type: 'TSInterfaceHeritage',
++         TSExpressionWithTypeArguments {
++           type: 'TSExpressionWithTypeArguments',
+            expression: Identifier {
+              type: 'Identifier',
+              name: 'C',
+
+              range: [26, 27],
+              loc: {
+                start: { column: 26, line: 1 },
+                end: { column: 27, line: 1 },
+              },
+            },
+
+            range: [26, 27],
+            loc: {
+              start: { column: 26, line: 1 },
+              end: { column: 27, line: 1 },
+            },
+          },
+        ],
+        id: Identifier {
+          type: 'Identifier',
+          name: 'F',
+
+          range: [10, 11],
+          loc: {
+            start: { column: 10, line: 1 },
+            end: { column: 11, line: 1 },
+          },
+        },
+
+        range: [0, 30],
+        loc: {
+          start: { column: 0, line: 1 },
+          end: { column: 30, line: 1 },
+        },
+      },
+    ],
+    sourceType: 'script',
+
+    range: [0, 31],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 0, line: 2 },
+    },
+  }"
+`;
diff --git a/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/extends-many/snapshots/6-AST-Alignment-Tokens.shot b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/extends-many/snapshots/6-AST-Alignment-Tokens.shot
new file mode 100644
index 000000000000..c6ea1aca49b7
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/extends-many/snapshots/6-AST-Alignment-Tokens.shot
@@ -0,0 +1,112 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSInterfaceDeclaration extends-many AST Alignment - Token 1`] = `
+"Snapshot Diff:
+- TSESTree
++ Babel
+
+  Array [
+-   Keyword {
+-     type: 'Keyword',
++   Identifier {
++     type: 'Identifier',
+      value: 'interface',
+
+      range: [0, 9],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 9, line: 1 },
+      },
+    },
+    Identifier {
+      type: 'Identifier',
+      value: 'F',
+
+      range: [10, 11],
+      loc: {
+        start: { column: 10, line: 1 },
+        end: { column: 11, line: 1 },
+      },
+    },
+    Keyword {
+      type: 'Keyword',
+      value: 'extends',
+
+      range: [12, 19],
+      loc: {
+        start: { column: 12, line: 1 },
+        end: { column: 19, line: 1 },
+      },
+    },
+    Identifier {
+      type: 'Identifier',
+      value: 'A',
+
+      range: [20, 21],
+      loc: {
+        start: { column: 20, line: 1 },
+        end: { column: 21, line: 1 },
+      },
+    },
+    Punctuator {
+      type: 'Punctuator',
+      value: ',',
+
+      range: [21, 22],
+      loc: {
+        start: { column: 21, line: 1 },
+        end: { column: 22, line: 1 },
+      },
+    },
+    Identifier {
+      type: 'Identifier',
+      value: 'B',
+
+      range: [23, 24],
+      loc: {
+        start: { column: 23, line: 1 },
+        end: { column: 24, line: 1 },
+      },
+    },
+    Punctuator {
+      type: 'Punctuator',
+      value: ',',
+
+      range: [24, 25],
+      loc: {
+        start: { column: 24, line: 1 },
+        end: { column: 25, line: 1 },
+      },
+    },
+    Identifier {
+      type: 'Identifier',
+      value: 'C',
+
+      range: [26, 27],
+      loc: {
+        start: { column: 26, line: 1 },
+        end: { column: 27, line: 1 },
+      },
+    },
+    Punctuator {
+      type: 'Punctuator',
+      value: '{',
+
+      range: [28, 29],
+      loc: {
+        start: { column: 28, line: 1 },
+        end: { column: 29, line: 1 },
+      },
+    },
+    Punctuator {
+      type: 'Punctuator',
+      value: '}',
+
+      range: [29, 30],
+      loc: {
+        start: { column: 29, line: 1 },
+        end: { column: 30, line: 1 },
+      },
+    },
+  ]"
+`;
diff --git a/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/extends-one/fixture.ts b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/extends-one/fixture.ts
new file mode 100644
index 000000000000..cd5394400b56
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/extends-one/fixture.ts
@@ -0,0 +1 @@
+interface F extends A {}
diff --git a/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/extends-one/snapshots/1-TSESTree-AST.shot b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/extends-one/snapshots/1-TSESTree-AST.shot
new file mode 100644
index 000000000000..795dc661bbe4
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/extends-one/snapshots/1-TSESTree-AST.shot
@@ -0,0 +1,66 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSInterfaceDeclaration extends-one TSESTree - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    TSInterfaceDeclaration {
+      type: "TSInterfaceDeclaration",
+      body: TSInterfaceBody {
+        type: "TSInterfaceBody",
+        body: Array [],
+
+        range: [22, 24],
+        loc: {
+          start: { column: 22, line: 1 },
+          end: { column: 24, line: 1 },
+        },
+      },
+      extends: Array [
+        TSInterfaceHeritage {
+          type: "TSInterfaceHeritage",
+          expression: Identifier {
+            type: "Identifier",
+            name: "A",
+
+            range: [20, 21],
+            loc: {
+              start: { column: 20, line: 1 },
+              end: { column: 21, line: 1 },
+            },
+          },
+
+          range: [20, 21],
+          loc: {
+            start: { column: 20, line: 1 },
+            end: { column: 21, line: 1 },
+          },
+        },
+      ],
+      id: Identifier {
+        type: "Identifier",
+        name: "F",
+
+        range: [10, 11],
+        loc: {
+          start: { column: 10, line: 1 },
+          end: { column: 11, line: 1 },
+        },
+      },
+
+      range: [0, 24],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 24, line: 1 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 25],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/extends-one/snapshots/2-TSESTree-Tokens.shot b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/extends-one/snapshots/2-TSESTree-Tokens.shot
new file mode 100644
index 000000000000..b9e3f8a240d6
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/extends-one/snapshots/2-TSESTree-Tokens.shot
@@ -0,0 +1,66 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSInterfaceDeclaration extends-one TSESTree - Tokens 1`] = `
+Array [
+  Keyword {
+    type: "Keyword",
+    value: "interface",
+
+    range: [0, 9],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 9, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "F",
+
+    range: [10, 11],
+    loc: {
+      start: { column: 10, line: 1 },
+      end: { column: 11, line: 1 },
+    },
+  },
+  Keyword {
+    type: "Keyword",
+    value: "extends",
+
+    range: [12, 19],
+    loc: {
+      start: { column: 12, line: 1 },
+      end: { column: 19, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "A",
+
+    range: [20, 21],
+    loc: {
+      start: { column: 20, line: 1 },
+      end: { column: 21, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "{",
+
+    range: [22, 23],
+    loc: {
+      start: { column: 22, line: 1 },
+      end: { column: 23, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "}",
+
+    range: [23, 24],
+    loc: {
+      start: { column: 23, line: 1 },
+      end: { column: 24, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/extends-one/snapshots/3-Babel-AST.shot b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/extends-one/snapshots/3-Babel-AST.shot
new file mode 100644
index 000000000000..87260af0dd55
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/extends-one/snapshots/3-Babel-AST.shot
@@ -0,0 +1,66 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSInterfaceDeclaration extends-one Babel - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    TSInterfaceDeclaration {
+      type: "TSInterfaceDeclaration",
+      body: TSInterfaceBody {
+        type: "TSInterfaceBody",
+        body: Array [],
+
+        range: [22, 24],
+        loc: {
+          start: { column: 22, line: 1 },
+          end: { column: 24, line: 1 },
+        },
+      },
+      extends: Array [
+        TSExpressionWithTypeArguments {
+          type: "TSExpressionWithTypeArguments",
+          expression: Identifier {
+            type: "Identifier",
+            name: "A",
+
+            range: [20, 21],
+            loc: {
+              start: { column: 20, line: 1 },
+              end: { column: 21, line: 1 },
+            },
+          },
+
+          range: [20, 21],
+          loc: {
+            start: { column: 20, line: 1 },
+            end: { column: 21, line: 1 },
+          },
+        },
+      ],
+      id: Identifier {
+        type: "Identifier",
+        name: "F",
+
+        range: [10, 11],
+        loc: {
+          start: { column: 10, line: 1 },
+          end: { column: 11, line: 1 },
+        },
+      },
+
+      range: [0, 24],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 24, line: 1 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 25],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/extends-one/snapshots/4-Babel-Tokens.shot b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/extends-one/snapshots/4-Babel-Tokens.shot
new file mode 100644
index 000000000000..26da7a11f7cc
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/extends-one/snapshots/4-Babel-Tokens.shot
@@ -0,0 +1,66 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSInterfaceDeclaration extends-one Babel - Tokens 1`] = `
+Array [
+  Identifier {
+    type: "Identifier",
+    value: "interface",
+
+    range: [0, 9],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 9, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "F",
+
+    range: [10, 11],
+    loc: {
+      start: { column: 10, line: 1 },
+      end: { column: 11, line: 1 },
+    },
+  },
+  Keyword {
+    type: "Keyword",
+    value: "extends",
+
+    range: [12, 19],
+    loc: {
+      start: { column: 12, line: 1 },
+      end: { column: 19, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "A",
+
+    range: [20, 21],
+    loc: {
+      start: { column: 20, line: 1 },
+      end: { column: 21, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "{",
+
+    range: [22, 23],
+    loc: {
+      start: { column: 22, line: 1 },
+      end: { column: 23, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "}",
+
+    range: [23, 24],
+    loc: {
+      start: { column: 23, line: 1 },
+      end: { column: 24, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/extends-one/snapshots/5-AST-Alignment-AST.shot b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/extends-one/snapshots/5-AST-Alignment-AST.shot
new file mode 100644
index 000000000000..fe6cf12f1a56
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/extends-one/snapshots/5-AST-Alignment-AST.shot
@@ -0,0 +1,72 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSInterfaceDeclaration extends-one AST Alignment - AST 1`] = `
+"Snapshot Diff:
+- TSESTree
++ Babel
+
+  Program {
+    type: 'Program',
+    body: Array [
+      TSInterfaceDeclaration {
+        type: 'TSInterfaceDeclaration',
+        body: TSInterfaceBody {
+          type: 'TSInterfaceBody',
+          body: Array [],
+
+          range: [22, 24],
+          loc: {
+            start: { column: 22, line: 1 },
+            end: { column: 24, line: 1 },
+          },
+        },
+        extends: Array [
+-         TSInterfaceHeritage {
+-           type: 'TSInterfaceHeritage',
++         TSExpressionWithTypeArguments {
++           type: 'TSExpressionWithTypeArguments',
+            expression: Identifier {
+              type: 'Identifier',
+              name: 'A',
+
+              range: [20, 21],
+              loc: {
+                start: { column: 20, line: 1 },
+                end: { column: 21, line: 1 },
+              },
+            },
+
+            range: [20, 21],
+            loc: {
+              start: { column: 20, line: 1 },
+              end: { column: 21, line: 1 },
+            },
+          },
+        ],
+        id: Identifier {
+          type: 'Identifier',
+          name: 'F',
+
+          range: [10, 11],
+          loc: {
+            start: { column: 10, line: 1 },
+            end: { column: 11, line: 1 },
+          },
+        },
+
+        range: [0, 24],
+        loc: {
+          start: { column: 0, line: 1 },
+          end: { column: 24, line: 1 },
+        },
+      },
+    ],
+    sourceType: 'script',
+
+    range: [0, 25],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 0, line: 2 },
+    },
+  }"
+`;
diff --git a/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/extends-one/snapshots/6-AST-Alignment-Tokens.shot b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/extends-one/snapshots/6-AST-Alignment-Tokens.shot
new file mode 100644
index 000000000000..f12bb69db9bb
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/extends-one/snapshots/6-AST-Alignment-Tokens.shot
@@ -0,0 +1,72 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSInterfaceDeclaration extends-one AST Alignment - Token 1`] = `
+"Snapshot Diff:
+- TSESTree
++ Babel
+
+  Array [
+-   Keyword {
+-     type: 'Keyword',
++   Identifier {
++     type: 'Identifier',
+      value: 'interface',
+
+      range: [0, 9],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 9, line: 1 },
+      },
+    },
+    Identifier {
+      type: 'Identifier',
+      value: 'F',
+
+      range: [10, 11],
+      loc: {
+        start: { column: 10, line: 1 },
+        end: { column: 11, line: 1 },
+      },
+    },
+    Keyword {
+      type: 'Keyword',
+      value: 'extends',
+
+      range: [12, 19],
+      loc: {
+        start: { column: 12, line: 1 },
+        end: { column: 19, line: 1 },
+      },
+    },
+    Identifier {
+      type: 'Identifier',
+      value: 'A',
+
+      range: [20, 21],
+      loc: {
+        start: { column: 20, line: 1 },
+        end: { column: 21, line: 1 },
+      },
+    },
+    Punctuator {
+      type: 'Punctuator',
+      value: '{',
+
+      range: [22, 23],
+      loc: {
+        start: { column: 22, line: 1 },
+        end: { column: 23, line: 1 },
+      },
+    },
+    Punctuator {
+      type: 'Punctuator',
+      value: '}',
+
+      range: [23, 24],
+      loc: {
+        start: { column: 23, line: 1 },
+        end: { column: 24, line: 1 },
+      },
+    },
+  ]"
+`;
diff --git a/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/type-param-many/fixture.ts b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/type-param-many/fixture.ts
new file mode 100644
index 000000000000..82042ece0e31
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/type-param-many/fixture.ts
@@ -0,0 +1 @@
+interface F<T, U, V> {}
diff --git a/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/type-param-many/snapshots/1-TSESTree-AST.shot b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/type-param-many/snapshots/1-TSESTree-AST.shot
new file mode 100644
index 000000000000..6aea3322462f
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/type-param-many/snapshots/1-TSESTree-AST.shot
@@ -0,0 +1,119 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSInterfaceDeclaration type-param-many TSESTree - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    TSInterfaceDeclaration {
+      type: "TSInterfaceDeclaration",
+      body: TSInterfaceBody {
+        type: "TSInterfaceBody",
+        body: Array [],
+
+        range: [21, 23],
+        loc: {
+          start: { column: 21, line: 1 },
+          end: { column: 23, line: 1 },
+        },
+      },
+      id: Identifier {
+        type: "Identifier",
+        name: "F",
+
+        range: [10, 11],
+        loc: {
+          start: { column: 10, line: 1 },
+          end: { column: 11, line: 1 },
+        },
+      },
+      typeParameters: TSTypeParameterDeclaration {
+        type: "TSTypeParameterDeclaration",
+        params: Array [
+          TSTypeParameter {
+            type: "TSTypeParameter",
+            in: false,
+            name: Identifier {
+              type: "Identifier",
+              name: "T",
+
+              range: [12, 13],
+              loc: {
+                start: { column: 12, line: 1 },
+                end: { column: 13, line: 1 },
+              },
+            },
+            out: false,
+
+            range: [12, 13],
+            loc: {
+              start: { column: 12, line: 1 },
+              end: { column: 13, line: 1 },
+            },
+          },
+          TSTypeParameter {
+            type: "TSTypeParameter",
+            in: false,
+            name: Identifier {
+              type: "Identifier",
+              name: "U",
+
+              range: [15, 16],
+              loc: {
+                start: { column: 15, line: 1 },
+                end: { column: 16, line: 1 },
+              },
+            },
+            out: false,
+
+            range: [15, 16],
+            loc: {
+              start: { column: 15, line: 1 },
+              end: { column: 16, line: 1 },
+            },
+          },
+          TSTypeParameter {
+            type: "TSTypeParameter",
+            in: false,
+            name: Identifier {
+              type: "Identifier",
+              name: "V",
+
+              range: [18, 19],
+              loc: {
+                start: { column: 18, line: 1 },
+                end: { column: 19, line: 1 },
+              },
+            },
+            out: false,
+
+            range: [18, 19],
+            loc: {
+              start: { column: 18, line: 1 },
+              end: { column: 19, line: 1 },
+            },
+          },
+        ],
+
+        range: [11, 20],
+        loc: {
+          start: { column: 11, line: 1 },
+          end: { column: 20, line: 1 },
+        },
+      },
+
+      range: [0, 23],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 23, line: 1 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 24],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/type-param-many/snapshots/2-TSESTree-Tokens.shot b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/type-param-many/snapshots/2-TSESTree-Tokens.shot
new file mode 100644
index 000000000000..d96cb3d9489e
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/type-param-many/snapshots/2-TSESTree-Tokens.shot
@@ -0,0 +1,116 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSInterfaceDeclaration type-param-many TSESTree - Tokens 1`] = `
+Array [
+  Keyword {
+    type: "Keyword",
+    value: "interface",
+
+    range: [0, 9],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 9, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "F",
+
+    range: [10, 11],
+    loc: {
+      start: { column: 10, line: 1 },
+      end: { column: 11, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "<",
+
+    range: [11, 12],
+    loc: {
+      start: { column: 11, line: 1 },
+      end: { column: 12, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "T",
+
+    range: [12, 13],
+    loc: {
+      start: { column: 12, line: 1 },
+      end: { column: 13, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ",",
+
+    range: [13, 14],
+    loc: {
+      start: { column: 13, line: 1 },
+      end: { column: 14, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "U",
+
+    range: [15, 16],
+    loc: {
+      start: { column: 15, line: 1 },
+      end: { column: 16, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ",",
+
+    range: [16, 17],
+    loc: {
+      start: { column: 16, line: 1 },
+      end: { column: 17, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "V",
+
+    range: [18, 19],
+    loc: {
+      start: { column: 18, line: 1 },
+      end: { column: 19, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ">",
+
+    range: [19, 20],
+    loc: {
+      start: { column: 19, line: 1 },
+      end: { column: 20, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "{",
+
+    range: [21, 22],
+    loc: {
+      start: { column: 21, line: 1 },
+      end: { column: 22, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "}",
+
+    range: [22, 23],
+    loc: {
+      start: { column: 22, line: 1 },
+      end: { column: 23, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/type-param-many/snapshots/3-Babel-AST.shot b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/type-param-many/snapshots/3-Babel-AST.shot
new file mode 100644
index 000000000000..579e9191d103
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/type-param-many/snapshots/3-Babel-AST.shot
@@ -0,0 +1,86 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSInterfaceDeclaration type-param-many Babel - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    TSInterfaceDeclaration {
+      type: "TSInterfaceDeclaration",
+      body: TSInterfaceBody {
+        type: "TSInterfaceBody",
+        body: Array [],
+
+        range: [21, 23],
+        loc: {
+          start: { column: 21, line: 1 },
+          end: { column: 23, line: 1 },
+        },
+      },
+      id: Identifier {
+        type: "Identifier",
+        name: "F",
+
+        range: [10, 11],
+        loc: {
+          start: { column: 10, line: 1 },
+          end: { column: 11, line: 1 },
+        },
+      },
+      typeParameters: TSTypeParameterDeclaration {
+        type: "TSTypeParameterDeclaration",
+        params: Array [
+          TSTypeParameter {
+            type: "TSTypeParameter",
+            name: "T",
+
+            range: [12, 13],
+            loc: {
+              start: { column: 12, line: 1 },
+              end: { column: 13, line: 1 },
+            },
+          },
+          TSTypeParameter {
+            type: "TSTypeParameter",
+            name: "U",
+
+            range: [15, 16],
+            loc: {
+              start: { column: 15, line: 1 },
+              end: { column: 16, line: 1 },
+            },
+          },
+          TSTypeParameter {
+            type: "TSTypeParameter",
+            name: "V",
+
+            range: [18, 19],
+            loc: {
+              start: { column: 18, line: 1 },
+              end: { column: 19, line: 1 },
+            },
+          },
+        ],
+
+        range: [11, 20],
+        loc: {
+          start: { column: 11, line: 1 },
+          end: { column: 20, line: 1 },
+        },
+      },
+
+      range: [0, 23],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 23, line: 1 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 24],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/type-param-many/snapshots/4-Babel-Tokens.shot b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/type-param-many/snapshots/4-Babel-Tokens.shot
new file mode 100644
index 000000000000..174304a412f4
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/type-param-many/snapshots/4-Babel-Tokens.shot
@@ -0,0 +1,116 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSInterfaceDeclaration type-param-many Babel - Tokens 1`] = `
+Array [
+  Identifier {
+    type: "Identifier",
+    value: "interface",
+
+    range: [0, 9],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 9, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "F",
+
+    range: [10, 11],
+    loc: {
+      start: { column: 10, line: 1 },
+      end: { column: 11, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "<",
+
+    range: [11, 12],
+    loc: {
+      start: { column: 11, line: 1 },
+      end: { column: 12, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "T",
+
+    range: [12, 13],
+    loc: {
+      start: { column: 12, line: 1 },
+      end: { column: 13, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ",",
+
+    range: [13, 14],
+    loc: {
+      start: { column: 13, line: 1 },
+      end: { column: 14, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "U",
+
+    range: [15, 16],
+    loc: {
+      start: { column: 15, line: 1 },
+      end: { column: 16, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ",",
+
+    range: [16, 17],
+    loc: {
+      start: { column: 16, line: 1 },
+      end: { column: 17, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "V",
+
+    range: [18, 19],
+    loc: {
+      start: { column: 18, line: 1 },
+      end: { column: 19, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ">",
+
+    range: [19, 20],
+    loc: {
+      start: { column: 19, line: 1 },
+      end: { column: 20, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "{",
+
+    range: [21, 22],
+    loc: {
+      start: { column: 21, line: 1 },
+      end: { column: 22, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "}",
+
+    range: [22, 23],
+    loc: {
+      start: { column: 22, line: 1 },
+      end: { column: 23, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/type-param-many/snapshots/5-AST-Alignment-AST.shot b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/type-param-many/snapshots/5-AST-Alignment-AST.shot
new file mode 100644
index 000000000000..56e43bd66323
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/type-param-many/snapshots/5-AST-Alignment-AST.shot
@@ -0,0 +1,126 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSInterfaceDeclaration type-param-many AST Alignment - AST 1`] = `
+"Snapshot Diff:
+- TSESTree
++ Babel
+
+  Program {
+    type: 'Program',
+    body: Array [
+      TSInterfaceDeclaration {
+        type: 'TSInterfaceDeclaration',
+        body: TSInterfaceBody {
+          type: 'TSInterfaceBody',
+          body: Array [],
+
+          range: [21, 23],
+          loc: {
+            start: { column: 21, line: 1 },
+            end: { column: 23, line: 1 },
+          },
+        },
+        id: Identifier {
+          type: 'Identifier',
+          name: 'F',
+
+          range: [10, 11],
+          loc: {
+            start: { column: 10, line: 1 },
+            end: { column: 11, line: 1 },
+          },
+        },
+        typeParameters: TSTypeParameterDeclaration {
+          type: 'TSTypeParameterDeclaration',
+          params: Array [
+            TSTypeParameter {
+              type: 'TSTypeParameter',
+-             in: false,
+-             name: Identifier {
+-               type: 'Identifier',
+-               name: 'T',
+-
+-               range: [12, 13],
+-               loc: {
+-                 start: { column: 12, line: 1 },
+-                 end: { column: 13, line: 1 },
+-               },
+-             },
+-             out: false,
++             name: 'T',
+
+              range: [12, 13],
+              loc: {
+                start: { column: 12, line: 1 },
+                end: { column: 13, line: 1 },
+              },
+            },
+            TSTypeParameter {
+              type: 'TSTypeParameter',
+-             in: false,
+-             name: Identifier {
+-               type: 'Identifier',
+-               name: 'U',
+-
+-               range: [15, 16],
+-               loc: {
+-                 start: { column: 15, line: 1 },
+-                 end: { column: 16, line: 1 },
+-               },
+-             },
+-             out: false,
++             name: 'U',
+
+              range: [15, 16],
+              loc: {
+                start: { column: 15, line: 1 },
+                end: { column: 16, line: 1 },
+              },
+            },
+            TSTypeParameter {
+              type: 'TSTypeParameter',
+-             in: false,
+-             name: Identifier {
+-               type: 'Identifier',
+-               name: 'V',
+-
+-               range: [18, 19],
+-               loc: {
+-                 start: { column: 18, line: 1 },
+-                 end: { column: 19, line: 1 },
+-               },
+-             },
+-             out: false,
++             name: 'V',
+
+              range: [18, 19],
+              loc: {
+                start: { column: 18, line: 1 },
+                end: { column: 19, line: 1 },
+              },
+            },
+          ],
+
+          range: [11, 20],
+          loc: {
+            start: { column: 11, line: 1 },
+            end: { column: 20, line: 1 },
+          },
+        },
+
+        range: [0, 23],
+        loc: {
+          start: { column: 0, line: 1 },
+          end: { column: 23, line: 1 },
+        },
+      },
+    ],
+    sourceType: 'script',
+
+    range: [0, 24],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 0, line: 2 },
+    },
+  }"
+`;
diff --git a/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/type-param-many/snapshots/6-AST-Alignment-Tokens.shot b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/type-param-many/snapshots/6-AST-Alignment-Tokens.shot
new file mode 100644
index 000000000000..889b7b8eba0e
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/type-param-many/snapshots/6-AST-Alignment-Tokens.shot
@@ -0,0 +1,122 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSInterfaceDeclaration type-param-many AST Alignment - Token 1`] = `
+"Snapshot Diff:
+- TSESTree
++ Babel
+
+  Array [
+-   Keyword {
+-     type: 'Keyword',
++   Identifier {
++     type: 'Identifier',
+      value: 'interface',
+
+      range: [0, 9],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 9, line: 1 },
+      },
+    },
+    Identifier {
+      type: 'Identifier',
+      value: 'F',
+
+      range: [10, 11],
+      loc: {
+        start: { column: 10, line: 1 },
+        end: { column: 11, line: 1 },
+      },
+    },
+    Punctuator {
+      type: 'Punctuator',
+      value: '<',
+
+      range: [11, 12],
+      loc: {
+        start: { column: 11, line: 1 },
+        end: { column: 12, line: 1 },
+      },
+    },
+    Identifier {
+      type: 'Identifier',
+      value: 'T',
+
+      range: [12, 13],
+      loc: {
+        start: { column: 12, line: 1 },
+        end: { column: 13, line: 1 },
+      },
+    },
+    Punctuator {
+      type: 'Punctuator',
+      value: ',',
+
+      range: [13, 14],
+      loc: {
+        start: { column: 13, line: 1 },
+        end: { column: 14, line: 1 },
+      },
+    },
+    Identifier {
+      type: 'Identifier',
+      value: 'U',
+
+      range: [15, 16],
+      loc: {
+        start: { column: 15, line: 1 },
+        end: { column: 16, line: 1 },
+      },
+    },
+    Punctuator {
+      type: 'Punctuator',
+      value: ',',
+
+      range: [16, 17],
+      loc: {
+        start: { column: 16, line: 1 },
+        end: { column: 17, line: 1 },
+      },
+    },
+    Identifier {
+      type: 'Identifier',
+      value: 'V',
+
+      range: [18, 19],
+      loc: {
+        start: { column: 18, line: 1 },
+        end: { column: 19, line: 1 },
+      },
+    },
+    Punctuator {
+      type: 'Punctuator',
+      value: '>',
+
+      range: [19, 20],
+      loc: {
+        start: { column: 19, line: 1 },
+        end: { column: 20, line: 1 },
+      },
+    },
+    Punctuator {
+      type: 'Punctuator',
+      value: '{',
+
+      range: [21, 22],
+      loc: {
+        start: { column: 21, line: 1 },
+        end: { column: 22, line: 1 },
+      },
+    },
+    Punctuator {
+      type: 'Punctuator',
+      value: '}',
+
+      range: [22, 23],
+      loc: {
+        start: { column: 22, line: 1 },
+        end: { column: 23, line: 1 },
+      },
+    },
+  ]"
+`;
diff --git a/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/type-param-one/fixture.ts b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/type-param-one/fixture.ts
new file mode 100644
index 000000000000..abd3720f1a68
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/type-param-one/fixture.ts
@@ -0,0 +1 @@
+interface F<T> {}
diff --git a/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/type-param-one/snapshots/1-TSESTree-AST.shot b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/type-param-one/snapshots/1-TSESTree-AST.shot
new file mode 100644
index 000000000000..15f674485662
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/type-param-one/snapshots/1-TSESTree-AST.shot
@@ -0,0 +1,77 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSInterfaceDeclaration type-param-one TSESTree - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    TSInterfaceDeclaration {
+      type: "TSInterfaceDeclaration",
+      body: TSInterfaceBody {
+        type: "TSInterfaceBody",
+        body: Array [],
+
+        range: [15, 17],
+        loc: {
+          start: { column: 15, line: 1 },
+          end: { column: 17, line: 1 },
+        },
+      },
+      id: Identifier {
+        type: "Identifier",
+        name: "F",
+
+        range: [10, 11],
+        loc: {
+          start: { column: 10, line: 1 },
+          end: { column: 11, line: 1 },
+        },
+      },
+      typeParameters: TSTypeParameterDeclaration {
+        type: "TSTypeParameterDeclaration",
+        params: Array [
+          TSTypeParameter {
+            type: "TSTypeParameter",
+            in: false,
+            name: Identifier {
+              type: "Identifier",
+              name: "T",
+
+              range: [12, 13],
+              loc: {
+                start: { column: 12, line: 1 },
+                end: { column: 13, line: 1 },
+              },
+            },
+            out: false,
+
+            range: [12, 13],
+            loc: {
+              start: { column: 12, line: 1 },
+              end: { column: 13, line: 1 },
+            },
+          },
+        ],
+
+        range: [11, 14],
+        loc: {
+          start: { column: 11, line: 1 },
+          end: { column: 14, line: 1 },
+        },
+      },
+
+      range: [0, 17],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 17, line: 1 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 18],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/type-param-one/snapshots/2-TSESTree-Tokens.shot b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/type-param-one/snapshots/2-TSESTree-Tokens.shot
new file mode 100644
index 000000000000..d88a78ec4006
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/type-param-one/snapshots/2-TSESTree-Tokens.shot
@@ -0,0 +1,76 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSInterfaceDeclaration type-param-one TSESTree - Tokens 1`] = `
+Array [
+  Keyword {
+    type: "Keyword",
+    value: "interface",
+
+    range: [0, 9],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 9, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "F",
+
+    range: [10, 11],
+    loc: {
+      start: { column: 10, line: 1 },
+      end: { column: 11, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "<",
+
+    range: [11, 12],
+    loc: {
+      start: { column: 11, line: 1 },
+      end: { column: 12, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "T",
+
+    range: [12, 13],
+    loc: {
+      start: { column: 12, line: 1 },
+      end: { column: 13, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ">",
+
+    range: [13, 14],
+    loc: {
+      start: { column: 13, line: 1 },
+      end: { column: 14, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "{",
+
+    range: [15, 16],
+    loc: {
+      start: { column: 15, line: 1 },
+      end: { column: 16, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "}",
+
+    range: [16, 17],
+    loc: {
+      start: { column: 16, line: 1 },
+      end: { column: 17, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/type-param-one/snapshots/3-Babel-AST.shot b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/type-param-one/snapshots/3-Babel-AST.shot
new file mode 100644
index 000000000000..dc81d623ecc1
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/type-param-one/snapshots/3-Babel-AST.shot
@@ -0,0 +1,66 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSInterfaceDeclaration type-param-one Babel - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    TSInterfaceDeclaration {
+      type: "TSInterfaceDeclaration",
+      body: TSInterfaceBody {
+        type: "TSInterfaceBody",
+        body: Array [],
+
+        range: [15, 17],
+        loc: {
+          start: { column: 15, line: 1 },
+          end: { column: 17, line: 1 },
+        },
+      },
+      id: Identifier {
+        type: "Identifier",
+        name: "F",
+
+        range: [10, 11],
+        loc: {
+          start: { column: 10, line: 1 },
+          end: { column: 11, line: 1 },
+        },
+      },
+      typeParameters: TSTypeParameterDeclaration {
+        type: "TSTypeParameterDeclaration",
+        params: Array [
+          TSTypeParameter {
+            type: "TSTypeParameter",
+            name: "T",
+
+            range: [12, 13],
+            loc: {
+              start: { column: 12, line: 1 },
+              end: { column: 13, line: 1 },
+            },
+          },
+        ],
+
+        range: [11, 14],
+        loc: {
+          start: { column: 11, line: 1 },
+          end: { column: 14, line: 1 },
+        },
+      },
+
+      range: [0, 17],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 17, line: 1 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 18],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/type-param-one/snapshots/4-Babel-Tokens.shot b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/type-param-one/snapshots/4-Babel-Tokens.shot
new file mode 100644
index 000000000000..a41373677b11
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/type-param-one/snapshots/4-Babel-Tokens.shot
@@ -0,0 +1,76 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSInterfaceDeclaration type-param-one Babel - Tokens 1`] = `
+Array [
+  Identifier {
+    type: "Identifier",
+    value: "interface",
+
+    range: [0, 9],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 9, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "F",
+
+    range: [10, 11],
+    loc: {
+      start: { column: 10, line: 1 },
+      end: { column: 11, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "<",
+
+    range: [11, 12],
+    loc: {
+      start: { column: 11, line: 1 },
+      end: { column: 12, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "T",
+
+    range: [12, 13],
+    loc: {
+      start: { column: 12, line: 1 },
+      end: { column: 13, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ">",
+
+    range: [13, 14],
+    loc: {
+      start: { column: 13, line: 1 },
+      end: { column: 14, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "{",
+
+    range: [15, 16],
+    loc: {
+      start: { column: 15, line: 1 },
+      end: { column: 16, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "}",
+
+    range: [16, 17],
+    loc: {
+      start: { column: 16, line: 1 },
+      end: { column: 17, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/type-param-one/snapshots/5-AST-Alignment-AST.shot b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/type-param-one/snapshots/5-AST-Alignment-AST.shot
new file mode 100644
index 000000000000..d6859d52b512
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/type-param-one/snapshots/5-AST-Alignment-AST.shot
@@ -0,0 +1,82 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSInterfaceDeclaration type-param-one AST Alignment - AST 1`] = `
+"Snapshot Diff:
+- TSESTree
++ Babel
+
+  Program {
+    type: 'Program',
+    body: Array [
+      TSInterfaceDeclaration {
+        type: 'TSInterfaceDeclaration',
+        body: TSInterfaceBody {
+          type: 'TSInterfaceBody',
+          body: Array [],
+
+          range: [15, 17],
+          loc: {
+            start: { column: 15, line: 1 },
+            end: { column: 17, line: 1 },
+          },
+        },
+        id: Identifier {
+          type: 'Identifier',
+          name: 'F',
+
+          range: [10, 11],
+          loc: {
+            start: { column: 10, line: 1 },
+            end: { column: 11, line: 1 },
+          },
+        },
+        typeParameters: TSTypeParameterDeclaration {
+          type: 'TSTypeParameterDeclaration',
+          params: Array [
+            TSTypeParameter {
+              type: 'TSTypeParameter',
+-             in: false,
+-             name: Identifier {
+-               type: 'Identifier',
+-               name: 'T',
+-
+-               range: [12, 13],
+-               loc: {
+-                 start: { column: 12, line: 1 },
+-                 end: { column: 13, line: 1 },
+-               },
+-             },
+-             out: false,
++             name: 'T',
+
+              range: [12, 13],
+              loc: {
+                start: { column: 12, line: 1 },
+                end: { column: 13, line: 1 },
+              },
+            },
+          ],
+
+          range: [11, 14],
+          loc: {
+            start: { column: 11, line: 1 },
+            end: { column: 14, line: 1 },
+          },
+        },
+
+        range: [0, 17],
+        loc: {
+          start: { column: 0, line: 1 },
+          end: { column: 17, line: 1 },
+        },
+      },
+    ],
+    sourceType: 'script',
+
+    range: [0, 18],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 0, line: 2 },
+    },
+  }"
+`;
diff --git a/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/type-param-one/snapshots/6-AST-Alignment-Tokens.shot b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/type-param-one/snapshots/6-AST-Alignment-Tokens.shot
new file mode 100644
index 000000000000..fc20247a46e5
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/type-param-one/snapshots/6-AST-Alignment-Tokens.shot
@@ -0,0 +1,82 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSInterfaceDeclaration type-param-one AST Alignment - Token 1`] = `
+"Snapshot Diff:
+- TSESTree
++ Babel
+
+  Array [
+-   Keyword {
+-     type: 'Keyword',
++   Identifier {
++     type: 'Identifier',
+      value: 'interface',
+
+      range: [0, 9],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 9, line: 1 },
+      },
+    },
+    Identifier {
+      type: 'Identifier',
+      value: 'F',
+
+      range: [10, 11],
+      loc: {
+        start: { column: 10, line: 1 },
+        end: { column: 11, line: 1 },
+      },
+    },
+    Punctuator {
+      type: 'Punctuator',
+      value: '<',
+
+      range: [11, 12],
+      loc: {
+        start: { column: 11, line: 1 },
+        end: { column: 12, line: 1 },
+      },
+    },
+    Identifier {
+      type: 'Identifier',
+      value: 'T',
+
+      range: [12, 13],
+      loc: {
+        start: { column: 12, line: 1 },
+        end: { column: 13, line: 1 },
+      },
+    },
+    Punctuator {
+      type: 'Punctuator',
+      value: '>',
+
+      range: [13, 14],
+      loc: {
+        start: { column: 13, line: 1 },
+        end: { column: 14, line: 1 },
+      },
+    },
+    Punctuator {
+      type: 'Punctuator',
+      value: '{',
+
+      range: [15, 16],
+      loc: {
+        start: { column: 15, line: 1 },
+        end: { column: 16, line: 1 },
+      },
+    },
+    Punctuator {
+      type: 'Punctuator',
+      value: '}',
+
+      range: [16, 17],
+      loc: {
+        start: { column: 16, line: 1 },
+        end: { column: 17, line: 1 },
+      },
+    },
+  ]"
+`;
diff --git a/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/with-member-one/fixture.ts b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/with-member-one/fixture.ts
new file mode 100644
index 000000000000..2f47465c4e0b
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/with-member-one/fixture.ts
@@ -0,0 +1,3 @@
+interface F {
+  prop;
+}
diff --git a/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/with-member-one/snapshots/1-TSESTree-AST.shot b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/with-member-one/snapshots/1-TSESTree-AST.shot
new file mode 100644
index 000000000000..424cf585b19b
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/with-member-one/snapshots/1-TSESTree-AST.shot
@@ -0,0 +1,66 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSInterfaceDeclaration with-member-one TSESTree - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    TSInterfaceDeclaration {
+      type: "TSInterfaceDeclaration",
+      body: TSInterfaceBody {
+        type: "TSInterfaceBody",
+        body: Array [
+          TSPropertySignature {
+            type: "TSPropertySignature",
+            computed: false,
+            key: Identifier {
+              type: "Identifier",
+              name: "prop",
+
+              range: [16, 20],
+              loc: {
+                start: { column: 2, line: 2 },
+                end: { column: 6, line: 2 },
+              },
+            },
+
+            range: [16, 21],
+            loc: {
+              start: { column: 2, line: 2 },
+              end: { column: 7, line: 2 },
+            },
+          },
+        ],
+
+        range: [12, 23],
+        loc: {
+          start: { column: 12, line: 1 },
+          end: { column: 1, line: 3 },
+        },
+      },
+      id: Identifier {
+        type: "Identifier",
+        name: "F",
+
+        range: [10, 11],
+        loc: {
+          start: { column: 10, line: 1 },
+          end: { column: 11, line: 1 },
+        },
+      },
+
+      range: [0, 23],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 1, line: 3 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 24],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 4 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/with-member-one/snapshots/2-TSESTree-Tokens.shot b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/with-member-one/snapshots/2-TSESTree-Tokens.shot
new file mode 100644
index 000000000000..c57ff756e66e
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/with-member-one/snapshots/2-TSESTree-Tokens.shot
@@ -0,0 +1,66 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSInterfaceDeclaration with-member-one TSESTree - Tokens 1`] = `
+Array [
+  Keyword {
+    type: "Keyword",
+    value: "interface",
+
+    range: [0, 9],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 9, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "F",
+
+    range: [10, 11],
+    loc: {
+      start: { column: 10, line: 1 },
+      end: { column: 11, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "{",
+
+    range: [12, 13],
+    loc: {
+      start: { column: 12, line: 1 },
+      end: { column: 13, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "prop",
+
+    range: [16, 20],
+    loc: {
+      start: { column: 2, line: 2 },
+      end: { column: 6, line: 2 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ";",
+
+    range: [20, 21],
+    loc: {
+      start: { column: 6, line: 2 },
+      end: { column: 7, line: 2 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "}",
+
+    range: [22, 23],
+    loc: {
+      start: { column: 0, line: 3 },
+      end: { column: 1, line: 3 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/with-member-one/snapshots/3-Babel-AST.shot b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/with-member-one/snapshots/3-Babel-AST.shot
new file mode 100644
index 000000000000..94437c371ec2
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/with-member-one/snapshots/3-Babel-AST.shot
@@ -0,0 +1,66 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSInterfaceDeclaration with-member-one Babel - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    TSInterfaceDeclaration {
+      type: "TSInterfaceDeclaration",
+      body: TSInterfaceBody {
+        type: "TSInterfaceBody",
+        body: Array [
+          TSPropertySignature {
+            type: "TSPropertySignature",
+            computed: false,
+            key: Identifier {
+              type: "Identifier",
+              name: "prop",
+
+              range: [16, 20],
+              loc: {
+                start: { column: 2, line: 2 },
+                end: { column: 6, line: 2 },
+              },
+            },
+
+            range: [16, 21],
+            loc: {
+              start: { column: 2, line: 2 },
+              end: { column: 7, line: 2 },
+            },
+          },
+        ],
+
+        range: [12, 23],
+        loc: {
+          start: { column: 12, line: 1 },
+          end: { column: 1, line: 3 },
+        },
+      },
+      id: Identifier {
+        type: "Identifier",
+        name: "F",
+
+        range: [10, 11],
+        loc: {
+          start: { column: 10, line: 1 },
+          end: { column: 11, line: 1 },
+        },
+      },
+
+      range: [0, 23],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 1, line: 3 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 24],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 4 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/with-member-one/snapshots/4-Babel-Tokens.shot b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/with-member-one/snapshots/4-Babel-Tokens.shot
new file mode 100644
index 000000000000..af379bd7026c
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/with-member-one/snapshots/4-Babel-Tokens.shot
@@ -0,0 +1,66 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSInterfaceDeclaration with-member-one Babel - Tokens 1`] = `
+Array [
+  Identifier {
+    type: "Identifier",
+    value: "interface",
+
+    range: [0, 9],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 9, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "F",
+
+    range: [10, 11],
+    loc: {
+      start: { column: 10, line: 1 },
+      end: { column: 11, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "{",
+
+    range: [12, 13],
+    loc: {
+      start: { column: 12, line: 1 },
+      end: { column: 13, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "prop",
+
+    range: [16, 20],
+    loc: {
+      start: { column: 2, line: 2 },
+      end: { column: 6, line: 2 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ";",
+
+    range: [20, 21],
+    loc: {
+      start: { column: 6, line: 2 },
+      end: { column: 7, line: 2 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "}",
+
+    range: [22, 23],
+    loc: {
+      start: { column: 0, line: 3 },
+      end: { column: 1, line: 3 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/with-member-one/snapshots/5-AST-Alignment-AST.shot b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/with-member-one/snapshots/5-AST-Alignment-AST.shot
new file mode 100644
index 000000000000..8e0b58b2efe7
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/with-member-one/snapshots/5-AST-Alignment-AST.shot
@@ -0,0 +1,6 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSInterfaceDeclaration with-member-one AST Alignment - AST 1`] = `
+"Snapshot Diff:
+Compared values have no visual difference."
+`;
diff --git a/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/with-member-one/snapshots/6-AST-Alignment-Tokens.shot b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/with-member-one/snapshots/6-AST-Alignment-Tokens.shot
new file mode 100644
index 000000000000..32b0173342da
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/fixtures/with-member-one/snapshots/6-AST-Alignment-Tokens.shot
@@ -0,0 +1,72 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSInterfaceDeclaration with-member-one AST Alignment - Token 1`] = `
+"Snapshot Diff:
+- TSESTree
++ Babel
+
+  Array [
+-   Keyword {
+-     type: 'Keyword',
++   Identifier {
++     type: 'Identifier',
+      value: 'interface',
+
+      range: [0, 9],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 9, line: 1 },
+      },
+    },
+    Identifier {
+      type: 'Identifier',
+      value: 'F',
+
+      range: [10, 11],
+      loc: {
+        start: { column: 10, line: 1 },
+        end: { column: 11, line: 1 },
+      },
+    },
+    Punctuator {
+      type: 'Punctuator',
+      value: '{',
+
+      range: [12, 13],
+      loc: {
+        start: { column: 12, line: 1 },
+        end: { column: 13, line: 1 },
+      },
+    },
+    Identifier {
+      type: 'Identifier',
+      value: 'prop',
+
+      range: [16, 20],
+      loc: {
+        start: { column: 2, line: 2 },
+        end: { column: 6, line: 2 },
+      },
+    },
+    Punctuator {
+      type: 'Punctuator',
+      value: ';',
+
+      range: [20, 21],
+      loc: {
+        start: { column: 6, line: 2 },
+        end: { column: 7, line: 2 },
+      },
+    },
+    Punctuator {
+      type: 'Punctuator',
+      value: '}',
+
+      range: [22, 23],
+      loc: {
+        start: { column: 0, line: 3 },
+        end: { column: 1, line: 3 },
+      },
+    },
+  ]"
+`;
diff --git a/packages/ast-spec/src/declaration/TSInterfaceDeclaration/spec.ts b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/spec.ts
index 1e95380c3cbb..a75c769daf92 100644
--- a/packages/ast-spec/src/declaration/TSInterfaceDeclaration/spec.ts
+++ b/packages/ast-spec/src/declaration/TSInterfaceDeclaration/spec.ts
@@ -7,11 +7,30 @@ import type { TSTypeParameterDeclaration } from '../../special/TSTypeParameterDe
 
 export interface TSInterfaceDeclaration extends BaseNode {
   type: AST_NODE_TYPES.TSInterfaceDeclaration;
+  // TODO(#4759) - breaking change remove this
+  abstract?: boolean;
+  /**
+   * The body of the interface
+   */
   body: TSInterfaceBody;
-  id: Identifier;
-  typeParameters?: TSTypeParameterDeclaration;
+  /**
+   * Whether the interface was `declare`d, `undefined` otherwise
+   */
+  // TODO(#5020) - make this `false` if it is not `declare`d
+  declare?: boolean;
+  /**
+   * The types this interface `extends`
+   */
   extends?: TSInterfaceHeritage[];
+  /**
+   * The name of this interface
+   */
+  id: Identifier;
+  // TODO(#4759) - breaking change remove this
   implements?: TSInterfaceHeritage[];
-  abstract?: boolean;
-  declare?: boolean;
+  /**
+   * The generic type parameters declared for the interface.
+   * This is `undefined` if there are no generic type parameters declared.
+   */
+  typeParameters?: TSTypeParameterDeclaration;
 }
diff --git a/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/_error_/module-invalid-id/fixture.ts b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/_error_/module-invalid-id/fixture.ts
new file mode 100644
index 000000000000..95cad2575043
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/_error_/module-invalid-id/fixture.ts
@@ -0,0 +1 @@
+module 1 {}
diff --git a/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/_error_/module-invalid-id/snapshots/1-TSESTree-Error.shot b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/_error_/module-invalid-id/snapshots/1-TSESTree-Error.shot
new file mode 100644
index 000000000000..082a7d854c2d
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/_error_/module-invalid-id/snapshots/1-TSESTree-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSModuleDeclaration _error_ module-invalid-id TSESTree - Error 1`] = `[TSError: Namespace name cannot be '1'.]`;
diff --git a/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/_error_/module-invalid-id/snapshots/2-Babel-Error.shot b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/_error_/module-invalid-id/snapshots/2-Babel-Error.shot
new file mode 100644
index 000000000000..9848b6e55cd4
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/_error_/module-invalid-id/snapshots/2-Babel-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSModuleDeclaration _error_ module-invalid-id Babel - Error 1`] = `[SyntaxError: Missing semicolon. (1:6)]`;
diff --git a/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/_error_/module-invalid-id/snapshots/3-Alignment-Error.shot b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/_error_/module-invalid-id/snapshots/3-Alignment-Error.shot
new file mode 100644
index 000000000000..1ed7cf1aba5a
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/_error_/module-invalid-id/snapshots/3-Alignment-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSModuleDeclaration _error_ module-invalid-id Error Alignment 1`] = `"Both errored"`;
diff --git a/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/_error_/module-missing-body/fixture.ts b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/_error_/module-missing-body/fixture.ts
new file mode 100644
index 000000000000..7d0dcd8add30
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/_error_/module-missing-body/fixture.ts
@@ -0,0 +1 @@
+module F;
diff --git a/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/_error_/module-missing-body/snapshots/1-TSESTree-Error.shot b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/_error_/module-missing-body/snapshots/1-TSESTree-Error.shot
new file mode 100644
index 000000000000..0a8a833a27ad
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/_error_/module-missing-body/snapshots/1-TSESTree-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSModuleDeclaration _error_ module-missing-body TSESTree - Error 1`] = `[TSError: '{' expected.]`;
diff --git a/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/_error_/module-missing-body/snapshots/2-Babel-Error.shot b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/_error_/module-missing-body/snapshots/2-Babel-Error.shot
new file mode 100644
index 000000000000..c7c0b7ca1d45
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/_error_/module-missing-body/snapshots/2-Babel-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSModuleDeclaration _error_ module-missing-body Babel - Error 1`] = `[SyntaxError: Unexpected token, expected "{" (1:8)]`;
diff --git a/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/_error_/module-missing-body/snapshots/3-Alignment-Error.shot b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/_error_/module-missing-body/snapshots/3-Alignment-Error.shot
new file mode 100644
index 000000000000..f8381f6dde37
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/_error_/module-missing-body/snapshots/3-Alignment-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSModuleDeclaration _error_ module-missing-body Error Alignment 1`] = `"Both errored"`;
diff --git a/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/_error_/namespace-declare-no-body/fixture.ts b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/_error_/namespace-declare-no-body/fixture.ts
new file mode 100644
index 000000000000..fe124427907e
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/_error_/namespace-declare-no-body/fixture.ts
@@ -0,0 +1 @@
+declare namespace F;
diff --git a/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/_error_/namespace-declare-no-body/snapshots/1-TSESTree-Error.shot b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/_error_/namespace-declare-no-body/snapshots/1-TSESTree-Error.shot
new file mode 100644
index 000000000000..6a1c0b8eebfd
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/_error_/namespace-declare-no-body/snapshots/1-TSESTree-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSModuleDeclaration _error_ namespace-declare-no-body TSESTree - Error 1`] = `[TSError: '{' expected.]`;
diff --git a/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/_error_/namespace-declare-no-body/snapshots/2-Babel-Error.shot b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/_error_/namespace-declare-no-body/snapshots/2-Babel-Error.shot
new file mode 100644
index 000000000000..0cc4df30bc58
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/_error_/namespace-declare-no-body/snapshots/2-Babel-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSModuleDeclaration _error_ namespace-declare-no-body Babel - Error 1`] = `[SyntaxError: Unexpected token, expected "{" (1:19)]`;
diff --git a/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/_error_/namespace-declare-no-body/snapshots/3-Alignment-Error.shot b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/_error_/namespace-declare-no-body/snapshots/3-Alignment-Error.shot
new file mode 100644
index 000000000000..62ff96dfe97d
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/_error_/namespace-declare-no-body/snapshots/3-Alignment-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSModuleDeclaration _error_ namespace-declare-no-body Error Alignment 1`] = `"Both errored"`;
diff --git a/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/_error_/namespace-id-literal/fixture.ts b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/_error_/namespace-id-literal/fixture.ts
new file mode 100644
index 000000000000..173024ac6a33
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/_error_/namespace-id-literal/fixture.ts
@@ -0,0 +1 @@
+namespace 'a' {}
diff --git a/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/_error_/namespace-id-literal/snapshots/1-TSESTree-Error.shot b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/_error_/namespace-id-literal/snapshots/1-TSESTree-Error.shot
new file mode 100644
index 000000000000..bdb99cfb914e
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/_error_/namespace-id-literal/snapshots/1-TSESTree-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSModuleDeclaration _error_ namespace-id-literal TSESTree - Error 1`] = `[TSError: Identifier expected.]`;
diff --git a/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/_error_/namespace-id-literal/snapshots/2-Babel-Error.shot b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/_error_/namespace-id-literal/snapshots/2-Babel-Error.shot
new file mode 100644
index 000000000000..3dc7480d32a2
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/_error_/namespace-id-literal/snapshots/2-Babel-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSModuleDeclaration _error_ namespace-id-literal Babel - Error 1`] = `[SyntaxError: Missing semicolon. (1:9)]`;
diff --git a/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/_error_/namespace-id-literal/snapshots/3-Alignment-Error.shot b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/_error_/namespace-id-literal/snapshots/3-Alignment-Error.shot
new file mode 100644
index 000000000000..354b7482759b
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/_error_/namespace-id-literal/snapshots/3-Alignment-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSModuleDeclaration _error_ namespace-id-literal Error Alignment 1`] = `"Both errored"`;
diff --git a/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/_error_/namespace-invalid-id/fixture.ts b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/_error_/namespace-invalid-id/fixture.ts
new file mode 100644
index 000000000000..32cdae5da4b7
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/_error_/namespace-invalid-id/fixture.ts
@@ -0,0 +1 @@
+namespace 1 {}
diff --git a/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/_error_/namespace-invalid-id/snapshots/1-TSESTree-Error.shot b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/_error_/namespace-invalid-id/snapshots/1-TSESTree-Error.shot
new file mode 100644
index 000000000000..3fbcf961cfad
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/_error_/namespace-invalid-id/snapshots/1-TSESTree-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSModuleDeclaration _error_ namespace-invalid-id TSESTree - Error 1`] = `[TSError: Namespace name cannot be '1'.]`;
diff --git a/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/_error_/namespace-invalid-id/snapshots/2-Babel-Error.shot b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/_error_/namespace-invalid-id/snapshots/2-Babel-Error.shot
new file mode 100644
index 000000000000..be52f2461a2a
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/_error_/namespace-invalid-id/snapshots/2-Babel-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSModuleDeclaration _error_ namespace-invalid-id Babel - Error 1`] = `[SyntaxError: Missing semicolon. (1:9)]`;
diff --git a/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/_error_/namespace-invalid-id/snapshots/3-Alignment-Error.shot b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/_error_/namespace-invalid-id/snapshots/3-Alignment-Error.shot
new file mode 100644
index 000000000000..1a3abc42ed72
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/_error_/namespace-invalid-id/snapshots/3-Alignment-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSModuleDeclaration _error_ namespace-invalid-id Error Alignment 1`] = `"Both errored"`;
diff --git a/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/_error_/namespace-no-body/fixture.ts b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/_error_/namespace-no-body/fixture.ts
new file mode 100644
index 000000000000..d0caf4acec49
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/_error_/namespace-no-body/fixture.ts
@@ -0,0 +1 @@
+namespace F;
diff --git a/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/_error_/namespace-no-body/snapshots/1-TSESTree-Error.shot b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/_error_/namespace-no-body/snapshots/1-TSESTree-Error.shot
new file mode 100644
index 000000000000..33a26d312caf
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/_error_/namespace-no-body/snapshots/1-TSESTree-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSModuleDeclaration _error_ namespace-no-body TSESTree - Error 1`] = `[TSError: '{' expected.]`;
diff --git a/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/_error_/namespace-no-body/snapshots/2-Babel-Error.shot b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/_error_/namespace-no-body/snapshots/2-Babel-Error.shot
new file mode 100644
index 000000000000..4e9e941de863
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/_error_/namespace-no-body/snapshots/2-Babel-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSModuleDeclaration _error_ namespace-no-body Babel - Error 1`] = `[SyntaxError: Unexpected token, expected "{" (1:11)]`;
diff --git a/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/_error_/namespace-no-body/snapshots/3-Alignment-Error.shot b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/_error_/namespace-no-body/snapshots/3-Alignment-Error.shot
new file mode 100644
index 000000000000..2c9165727c10
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/_error_/namespace-no-body/snapshots/3-Alignment-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSModuleDeclaration _error_ namespace-no-body Error Alignment 1`] = `"Both errored"`;
diff --git a/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/global/fixture.ts b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/global/fixture.ts
new file mode 100644
index 000000000000..3f1ee73dee12
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/global/fixture.ts
@@ -0,0 +1 @@
+declare global {}
diff --git a/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/global/snapshots/1-TSESTree-AST.shot b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/global/snapshots/1-TSESTree-AST.shot
new file mode 100644
index 000000000000..424909a0e10c
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/global/snapshots/1-TSESTree-AST.shot
@@ -0,0 +1,47 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSModuleDeclaration global TSESTree - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    TSModuleDeclaration {
+      type: "TSModuleDeclaration",
+      body: TSModuleBlock {
+        type: "TSModuleBlock",
+        body: Array [],
+
+        range: [15, 17],
+        loc: {
+          start: { column: 15, line: 1 },
+          end: { column: 17, line: 1 },
+        },
+      },
+      declare: true,
+      global: true,
+      id: Identifier {
+        type: "Identifier",
+        name: "global",
+
+        range: [8, 14],
+        loc: {
+          start: { column: 8, line: 1 },
+          end: { column: 14, line: 1 },
+        },
+      },
+
+      range: [0, 17],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 17, line: 1 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 18],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/global/snapshots/2-TSESTree-Tokens.shot b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/global/snapshots/2-TSESTree-Tokens.shot
new file mode 100644
index 000000000000..910131ba7b8c
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/global/snapshots/2-TSESTree-Tokens.shot
@@ -0,0 +1,46 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSModuleDeclaration global TSESTree - Tokens 1`] = `
+Array [
+  Identifier {
+    type: "Identifier",
+    value: "declare",
+
+    range: [0, 7],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 7, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "global",
+
+    range: [8, 14],
+    loc: {
+      start: { column: 8, line: 1 },
+      end: { column: 14, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "{",
+
+    range: [15, 16],
+    loc: {
+      start: { column: 15, line: 1 },
+      end: { column: 16, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "}",
+
+    range: [16, 17],
+    loc: {
+      start: { column: 16, line: 1 },
+      end: { column: 17, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/global/snapshots/3-Babel-AST.shot b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/global/snapshots/3-Babel-AST.shot
new file mode 100644
index 000000000000..4e1a238040b4
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/global/snapshots/3-Babel-AST.shot
@@ -0,0 +1,47 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSModuleDeclaration global Babel - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    TSModuleDeclaration {
+      type: "TSModuleDeclaration",
+      body: TSModuleBlock {
+        type: "TSModuleBlock",
+        body: Array [],
+
+        range: [15, 17],
+        loc: {
+          start: { column: 15, line: 1 },
+          end: { column: 17, line: 1 },
+        },
+      },
+      declare: true,
+      global: true,
+      id: Identifier {
+        type: "Identifier",
+        name: "global",
+
+        range: [8, 14],
+        loc: {
+          start: { column: 8, line: 1 },
+          end: { column: 14, line: 1 },
+        },
+      },
+
+      range: [0, 17],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 17, line: 1 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 18],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/global/snapshots/4-Babel-Tokens.shot b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/global/snapshots/4-Babel-Tokens.shot
new file mode 100644
index 000000000000..393012dfc4b8
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/global/snapshots/4-Babel-Tokens.shot
@@ -0,0 +1,46 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSModuleDeclaration global Babel - Tokens 1`] = `
+Array [
+  Identifier {
+    type: "Identifier",
+    value: "declare",
+
+    range: [0, 7],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 7, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "global",
+
+    range: [8, 14],
+    loc: {
+      start: { column: 8, line: 1 },
+      end: { column: 14, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "{",
+
+    range: [15, 16],
+    loc: {
+      start: { column: 15, line: 1 },
+      end: { column: 16, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "}",
+
+    range: [16, 17],
+    loc: {
+      start: { column: 16, line: 1 },
+      end: { column: 17, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/global/snapshots/5-AST-Alignment-AST.shot b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/global/snapshots/5-AST-Alignment-AST.shot
new file mode 100644
index 000000000000..bdf259261537
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/global/snapshots/5-AST-Alignment-AST.shot
@@ -0,0 +1,6 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSModuleDeclaration global AST Alignment - AST 1`] = `
+"Snapshot Diff:
+Compared values have no visual difference."
+`;
diff --git a/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/global/snapshots/6-AST-Alignment-Tokens.shot b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/global/snapshots/6-AST-Alignment-Tokens.shot
new file mode 100644
index 000000000000..b92eb152c95b
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/global/snapshots/6-AST-Alignment-Tokens.shot
@@ -0,0 +1,6 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSModuleDeclaration global AST Alignment - Token 1`] = `
+"Snapshot Diff:
+Compared values have no visual difference."
+`;
diff --git a/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-declare-no-body/fixture.ts b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-declare-no-body/fixture.ts
new file mode 100644
index 000000000000..2758941f3c3a
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-declare-no-body/fixture.ts
@@ -0,0 +1 @@
+declare module 'a';
diff --git a/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-declare-no-body/snapshots/1-TSESTree-AST.shot b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-declare-no-body/snapshots/1-TSESTree-AST.shot
new file mode 100644
index 000000000000..a0ad297f73cd
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-declare-no-body/snapshots/1-TSESTree-AST.shot
@@ -0,0 +1,37 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSModuleDeclaration module-declare-no-body TSESTree - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    TSModuleDeclaration {
+      type: "TSModuleDeclaration",
+      declare: true,
+      id: Literal {
+        type: "Literal",
+        raw: "'a'",
+        value: "a",
+
+        range: [15, 18],
+        loc: {
+          start: { column: 15, line: 1 },
+          end: { column: 18, line: 1 },
+        },
+      },
+
+      range: [0, 19],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 19, line: 1 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 20],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-declare-no-body/snapshots/2-TSESTree-Tokens.shot b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-declare-no-body/snapshots/2-TSESTree-Tokens.shot
new file mode 100644
index 000000000000..0c2959419e23
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-declare-no-body/snapshots/2-TSESTree-Tokens.shot
@@ -0,0 +1,46 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSModuleDeclaration module-declare-no-body TSESTree - Tokens 1`] = `
+Array [
+  Identifier {
+    type: "Identifier",
+    value: "declare",
+
+    range: [0, 7],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 7, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "module",
+
+    range: [8, 14],
+    loc: {
+      start: { column: 8, line: 1 },
+      end: { column: 14, line: 1 },
+    },
+  },
+  String {
+    type: "String",
+    value: "'a'",
+
+    range: [15, 18],
+    loc: {
+      start: { column: 15, line: 1 },
+      end: { column: 18, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ";",
+
+    range: [18, 19],
+    loc: {
+      start: { column: 18, line: 1 },
+      end: { column: 19, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-declare-no-body/snapshots/3-Babel-AST.shot b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-declare-no-body/snapshots/3-Babel-AST.shot
new file mode 100644
index 000000000000..d90a0fdea6a6
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-declare-no-body/snapshots/3-Babel-AST.shot
@@ -0,0 +1,37 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSModuleDeclaration module-declare-no-body Babel - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    TSModuleDeclaration {
+      type: "TSModuleDeclaration",
+      declare: true,
+      id: Literal {
+        type: "Literal",
+        raw: "'a'",
+        value: "a",
+
+        range: [15, 18],
+        loc: {
+          start: { column: 15, line: 1 },
+          end: { column: 18, line: 1 },
+        },
+      },
+
+      range: [0, 19],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 19, line: 1 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 20],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-declare-no-body/snapshots/4-Babel-Tokens.shot b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-declare-no-body/snapshots/4-Babel-Tokens.shot
new file mode 100644
index 000000000000..d6f2b8430a15
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-declare-no-body/snapshots/4-Babel-Tokens.shot
@@ -0,0 +1,46 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSModuleDeclaration module-declare-no-body Babel - Tokens 1`] = `
+Array [
+  Identifier {
+    type: "Identifier",
+    value: "declare",
+
+    range: [0, 7],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 7, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "module",
+
+    range: [8, 14],
+    loc: {
+      start: { column: 8, line: 1 },
+      end: { column: 14, line: 1 },
+    },
+  },
+  String {
+    type: "String",
+    value: "'a'",
+
+    range: [15, 18],
+    loc: {
+      start: { column: 15, line: 1 },
+      end: { column: 18, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ";",
+
+    range: [18, 19],
+    loc: {
+      start: { column: 18, line: 1 },
+      end: { column: 19, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-declare-no-body/snapshots/5-AST-Alignment-AST.shot b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-declare-no-body/snapshots/5-AST-Alignment-AST.shot
new file mode 100644
index 000000000000..29dc0c7a7765
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-declare-no-body/snapshots/5-AST-Alignment-AST.shot
@@ -0,0 +1,6 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSModuleDeclaration module-declare-no-body AST Alignment - AST 1`] = `
+"Snapshot Diff:
+Compared values have no visual difference."
+`;
diff --git a/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-declare-no-body/snapshots/6-AST-Alignment-Tokens.shot b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-declare-no-body/snapshots/6-AST-Alignment-Tokens.shot
new file mode 100644
index 000000000000..6341815959d2
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-declare-no-body/snapshots/6-AST-Alignment-Tokens.shot
@@ -0,0 +1,6 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSModuleDeclaration module-declare-no-body AST Alignment - Token 1`] = `
+"Snapshot Diff:
+Compared values have no visual difference."
+`;
diff --git a/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-declare/fixture.ts b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-declare/fixture.ts
new file mode 100644
index 000000000000..2cbec48309b3
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-declare/fixture.ts
@@ -0,0 +1 @@
+declare module F {}
diff --git a/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-declare/snapshots/1-TSESTree-AST.shot b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-declare/snapshots/1-TSESTree-AST.shot
new file mode 100644
index 000000000000..74a329eeb585
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-declare/snapshots/1-TSESTree-AST.shot
@@ -0,0 +1,46 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSModuleDeclaration module-declare TSESTree - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    TSModuleDeclaration {
+      type: "TSModuleDeclaration",
+      body: TSModuleBlock {
+        type: "TSModuleBlock",
+        body: Array [],
+
+        range: [17, 19],
+        loc: {
+          start: { column: 17, line: 1 },
+          end: { column: 19, line: 1 },
+        },
+      },
+      declare: true,
+      id: Identifier {
+        type: "Identifier",
+        name: "F",
+
+        range: [15, 16],
+        loc: {
+          start: { column: 15, line: 1 },
+          end: { column: 16, line: 1 },
+        },
+      },
+
+      range: [0, 19],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 19, line: 1 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 20],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-declare/snapshots/2-TSESTree-Tokens.shot b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-declare/snapshots/2-TSESTree-Tokens.shot
new file mode 100644
index 000000000000..487f26037f87
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-declare/snapshots/2-TSESTree-Tokens.shot
@@ -0,0 +1,56 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSModuleDeclaration module-declare TSESTree - Tokens 1`] = `
+Array [
+  Identifier {
+    type: "Identifier",
+    value: "declare",
+
+    range: [0, 7],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 7, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "module",
+
+    range: [8, 14],
+    loc: {
+      start: { column: 8, line: 1 },
+      end: { column: 14, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "F",
+
+    range: [15, 16],
+    loc: {
+      start: { column: 15, line: 1 },
+      end: { column: 16, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "{",
+
+    range: [17, 18],
+    loc: {
+      start: { column: 17, line: 1 },
+      end: { column: 18, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "}",
+
+    range: [18, 19],
+    loc: {
+      start: { column: 18, line: 1 },
+      end: { column: 19, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-declare/snapshots/3-Babel-AST.shot b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-declare/snapshots/3-Babel-AST.shot
new file mode 100644
index 000000000000..dd00b5173a18
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-declare/snapshots/3-Babel-AST.shot
@@ -0,0 +1,46 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSModuleDeclaration module-declare Babel - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    TSModuleDeclaration {
+      type: "TSModuleDeclaration",
+      body: TSModuleBlock {
+        type: "TSModuleBlock",
+        body: Array [],
+
+        range: [17, 19],
+        loc: {
+          start: { column: 17, line: 1 },
+          end: { column: 19, line: 1 },
+        },
+      },
+      declare: true,
+      id: Identifier {
+        type: "Identifier",
+        name: "F",
+
+        range: [15, 16],
+        loc: {
+          start: { column: 15, line: 1 },
+          end: { column: 16, line: 1 },
+        },
+      },
+
+      range: [0, 19],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 19, line: 1 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 20],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-declare/snapshots/4-Babel-Tokens.shot b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-declare/snapshots/4-Babel-Tokens.shot
new file mode 100644
index 000000000000..e2dfc2330dcb
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-declare/snapshots/4-Babel-Tokens.shot
@@ -0,0 +1,56 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSModuleDeclaration module-declare Babel - Tokens 1`] = `
+Array [
+  Identifier {
+    type: "Identifier",
+    value: "declare",
+
+    range: [0, 7],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 7, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "module",
+
+    range: [8, 14],
+    loc: {
+      start: { column: 8, line: 1 },
+      end: { column: 14, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "F",
+
+    range: [15, 16],
+    loc: {
+      start: { column: 15, line: 1 },
+      end: { column: 16, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "{",
+
+    range: [17, 18],
+    loc: {
+      start: { column: 17, line: 1 },
+      end: { column: 18, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "}",
+
+    range: [18, 19],
+    loc: {
+      start: { column: 18, line: 1 },
+      end: { column: 19, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-declare/snapshots/5-AST-Alignment-AST.shot b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-declare/snapshots/5-AST-Alignment-AST.shot
new file mode 100644
index 000000000000..d70930f793c0
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-declare/snapshots/5-AST-Alignment-AST.shot
@@ -0,0 +1,6 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSModuleDeclaration module-declare AST Alignment - AST 1`] = `
+"Snapshot Diff:
+Compared values have no visual difference."
+`;
diff --git a/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-declare/snapshots/6-AST-Alignment-Tokens.shot b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-declare/snapshots/6-AST-Alignment-Tokens.shot
new file mode 100644
index 000000000000..bae19f0bd143
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-declare/snapshots/6-AST-Alignment-Tokens.shot
@@ -0,0 +1,6 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSModuleDeclaration module-declare AST Alignment - Token 1`] = `
+"Snapshot Diff:
+Compared values have no visual difference."
+`;
diff --git a/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-id-identifier/fixture.ts b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-id-identifier/fixture.ts
new file mode 100644
index 000000000000..499f11944678
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-id-identifier/fixture.ts
@@ -0,0 +1 @@
+module F {}
diff --git a/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-id-identifier/snapshots/1-TSESTree-AST.shot b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-id-identifier/snapshots/1-TSESTree-AST.shot
new file mode 100644
index 000000000000..3559c1ce1a19
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-id-identifier/snapshots/1-TSESTree-AST.shot
@@ -0,0 +1,45 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSModuleDeclaration module-id-identifier TSESTree - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    TSModuleDeclaration {
+      type: "TSModuleDeclaration",
+      body: TSModuleBlock {
+        type: "TSModuleBlock",
+        body: Array [],
+
+        range: [9, 11],
+        loc: {
+          start: { column: 9, line: 1 },
+          end: { column: 11, line: 1 },
+        },
+      },
+      id: Identifier {
+        type: "Identifier",
+        name: "F",
+
+        range: [7, 8],
+        loc: {
+          start: { column: 7, line: 1 },
+          end: { column: 8, line: 1 },
+        },
+      },
+
+      range: [0, 11],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 11, line: 1 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 12],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-id-identifier/snapshots/2-TSESTree-Tokens.shot b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-id-identifier/snapshots/2-TSESTree-Tokens.shot
new file mode 100644
index 000000000000..e8658090b431
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-id-identifier/snapshots/2-TSESTree-Tokens.shot
@@ -0,0 +1,46 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSModuleDeclaration module-id-identifier TSESTree - Tokens 1`] = `
+Array [
+  Identifier {
+    type: "Identifier",
+    value: "module",
+
+    range: [0, 6],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 6, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "F",
+
+    range: [7, 8],
+    loc: {
+      start: { column: 7, line: 1 },
+      end: { column: 8, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "{",
+
+    range: [9, 10],
+    loc: {
+      start: { column: 9, line: 1 },
+      end: { column: 10, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "}",
+
+    range: [10, 11],
+    loc: {
+      start: { column: 10, line: 1 },
+      end: { column: 11, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-id-identifier/snapshots/3-Babel-AST.shot b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-id-identifier/snapshots/3-Babel-AST.shot
new file mode 100644
index 000000000000..7acb1bcd8716
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-id-identifier/snapshots/3-Babel-AST.shot
@@ -0,0 +1,45 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSModuleDeclaration module-id-identifier Babel - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    TSModuleDeclaration {
+      type: "TSModuleDeclaration",
+      body: TSModuleBlock {
+        type: "TSModuleBlock",
+        body: Array [],
+
+        range: [9, 11],
+        loc: {
+          start: { column: 9, line: 1 },
+          end: { column: 11, line: 1 },
+        },
+      },
+      id: Identifier {
+        type: "Identifier",
+        name: "F",
+
+        range: [7, 8],
+        loc: {
+          start: { column: 7, line: 1 },
+          end: { column: 8, line: 1 },
+        },
+      },
+
+      range: [0, 11],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 11, line: 1 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 12],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-id-identifier/snapshots/4-Babel-Tokens.shot b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-id-identifier/snapshots/4-Babel-Tokens.shot
new file mode 100644
index 000000000000..f8093f686fb0
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-id-identifier/snapshots/4-Babel-Tokens.shot
@@ -0,0 +1,46 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSModuleDeclaration module-id-identifier Babel - Tokens 1`] = `
+Array [
+  Identifier {
+    type: "Identifier",
+    value: "module",
+
+    range: [0, 6],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 6, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "F",
+
+    range: [7, 8],
+    loc: {
+      start: { column: 7, line: 1 },
+      end: { column: 8, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "{",
+
+    range: [9, 10],
+    loc: {
+      start: { column: 9, line: 1 },
+      end: { column: 10, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "}",
+
+    range: [10, 11],
+    loc: {
+      start: { column: 10, line: 1 },
+      end: { column: 11, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-id-identifier/snapshots/5-AST-Alignment-AST.shot b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-id-identifier/snapshots/5-AST-Alignment-AST.shot
new file mode 100644
index 000000000000..829de93e3df2
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-id-identifier/snapshots/5-AST-Alignment-AST.shot
@@ -0,0 +1,6 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSModuleDeclaration module-id-identifier AST Alignment - AST 1`] = `
+"Snapshot Diff:
+Compared values have no visual difference."
+`;
diff --git a/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-id-identifier/snapshots/6-AST-Alignment-Tokens.shot b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-id-identifier/snapshots/6-AST-Alignment-Tokens.shot
new file mode 100644
index 000000000000..2d09487a6621
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-id-identifier/snapshots/6-AST-Alignment-Tokens.shot
@@ -0,0 +1,6 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSModuleDeclaration module-id-identifier AST Alignment - Token 1`] = `
+"Snapshot Diff:
+Compared values have no visual difference."
+`;
diff --git a/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-id-literal/fixture.ts b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-id-literal/fixture.ts
new file mode 100644
index 000000000000..6e2ddacd2530
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-id-literal/fixture.ts
@@ -0,0 +1 @@
+module 'a' {}
diff --git a/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-id-literal/snapshots/1-TSESTree-AST.shot b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-id-literal/snapshots/1-TSESTree-AST.shot
new file mode 100644
index 000000000000..da4f7cdc9afb
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-id-literal/snapshots/1-TSESTree-AST.shot
@@ -0,0 +1,46 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSModuleDeclaration module-id-literal TSESTree - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    TSModuleDeclaration {
+      type: "TSModuleDeclaration",
+      body: TSModuleBlock {
+        type: "TSModuleBlock",
+        body: Array [],
+
+        range: [11, 13],
+        loc: {
+          start: { column: 11, line: 1 },
+          end: { column: 13, line: 1 },
+        },
+      },
+      id: Literal {
+        type: "Literal",
+        raw: "'a'",
+        value: "a",
+
+        range: [7, 10],
+        loc: {
+          start: { column: 7, line: 1 },
+          end: { column: 10, line: 1 },
+        },
+      },
+
+      range: [0, 13],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 13, line: 1 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 14],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-id-literal/snapshots/2-TSESTree-Tokens.shot b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-id-literal/snapshots/2-TSESTree-Tokens.shot
new file mode 100644
index 000000000000..35a1efd6dc9c
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-id-literal/snapshots/2-TSESTree-Tokens.shot
@@ -0,0 +1,46 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSModuleDeclaration module-id-literal TSESTree - Tokens 1`] = `
+Array [
+  Identifier {
+    type: "Identifier",
+    value: "module",
+
+    range: [0, 6],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 6, line: 1 },
+    },
+  },
+  String {
+    type: "String",
+    value: "'a'",
+
+    range: [7, 10],
+    loc: {
+      start: { column: 7, line: 1 },
+      end: { column: 10, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "{",
+
+    range: [11, 12],
+    loc: {
+      start: { column: 11, line: 1 },
+      end: { column: 12, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "}",
+
+    range: [12, 13],
+    loc: {
+      start: { column: 12, line: 1 },
+      end: { column: 13, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-id-literal/snapshots/3-Babel-AST.shot b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-id-literal/snapshots/3-Babel-AST.shot
new file mode 100644
index 000000000000..fafc835ec472
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-id-literal/snapshots/3-Babel-AST.shot
@@ -0,0 +1,46 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSModuleDeclaration module-id-literal Babel - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    TSModuleDeclaration {
+      type: "TSModuleDeclaration",
+      body: TSModuleBlock {
+        type: "TSModuleBlock",
+        body: Array [],
+
+        range: [11, 13],
+        loc: {
+          start: { column: 11, line: 1 },
+          end: { column: 13, line: 1 },
+        },
+      },
+      id: Literal {
+        type: "Literal",
+        raw: "'a'",
+        value: "a",
+
+        range: [7, 10],
+        loc: {
+          start: { column: 7, line: 1 },
+          end: { column: 10, line: 1 },
+        },
+      },
+
+      range: [0, 13],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 13, line: 1 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 14],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-id-literal/snapshots/4-Babel-Tokens.shot b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-id-literal/snapshots/4-Babel-Tokens.shot
new file mode 100644
index 000000000000..a463f80b9e5b
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-id-literal/snapshots/4-Babel-Tokens.shot
@@ -0,0 +1,46 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSModuleDeclaration module-id-literal Babel - Tokens 1`] = `
+Array [
+  Identifier {
+    type: "Identifier",
+    value: "module",
+
+    range: [0, 6],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 6, line: 1 },
+    },
+  },
+  String {
+    type: "String",
+    value: "'a'",
+
+    range: [7, 10],
+    loc: {
+      start: { column: 7, line: 1 },
+      end: { column: 10, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "{",
+
+    range: [11, 12],
+    loc: {
+      start: { column: 11, line: 1 },
+      end: { column: 12, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "}",
+
+    range: [12, 13],
+    loc: {
+      start: { column: 12, line: 1 },
+      end: { column: 13, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-id-literal/snapshots/5-AST-Alignment-AST.shot b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-id-literal/snapshots/5-AST-Alignment-AST.shot
new file mode 100644
index 000000000000..f13f22dfe7df
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-id-literal/snapshots/5-AST-Alignment-AST.shot
@@ -0,0 +1,6 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSModuleDeclaration module-id-literal AST Alignment - AST 1`] = `
+"Snapshot Diff:
+Compared values have no visual difference."
+`;
diff --git a/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-id-literal/snapshots/6-AST-Alignment-Tokens.shot b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-id-literal/snapshots/6-AST-Alignment-Tokens.shot
new file mode 100644
index 000000000000..1e1bc9d73c32
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-id-literal/snapshots/6-AST-Alignment-Tokens.shot
@@ -0,0 +1,6 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSModuleDeclaration module-id-literal AST Alignment - Token 1`] = `
+"Snapshot Diff:
+Compared values have no visual difference."
+`;
diff --git a/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-id-qualified-name/fixture.ts b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-id-qualified-name/fixture.ts
new file mode 100644
index 000000000000..56162d5e58b1
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-id-qualified-name/fixture.ts
@@ -0,0 +1 @@
+module A.B.C {}
diff --git a/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-id-qualified-name/snapshots/1-TSESTree-AST.shot b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-id-qualified-name/snapshots/1-TSESTree-AST.shot
new file mode 100644
index 000000000000..3dfc069dda7e
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-id-qualified-name/snapshots/1-TSESTree-AST.shot
@@ -0,0 +1,83 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSModuleDeclaration module-id-qualified-name TSESTree - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    TSModuleDeclaration {
+      type: "TSModuleDeclaration",
+      body: TSModuleDeclaration {
+        type: "TSModuleDeclaration",
+        body: TSModuleDeclaration {
+          type: "TSModuleDeclaration",
+          body: TSModuleBlock {
+            type: "TSModuleBlock",
+            body: Array [],
+
+            range: [13, 15],
+            loc: {
+              start: { column: 13, line: 1 },
+              end: { column: 15, line: 1 },
+            },
+          },
+          id: Identifier {
+            type: "Identifier",
+            name: "C",
+
+            range: [11, 12],
+            loc: {
+              start: { column: 11, line: 1 },
+              end: { column: 12, line: 1 },
+            },
+          },
+
+          range: [11, 15],
+          loc: {
+            start: { column: 11, line: 1 },
+            end: { column: 15, line: 1 },
+          },
+        },
+        id: Identifier {
+          type: "Identifier",
+          name: "B",
+
+          range: [9, 10],
+          loc: {
+            start: { column: 9, line: 1 },
+            end: { column: 10, line: 1 },
+          },
+        },
+
+        range: [9, 15],
+        loc: {
+          start: { column: 9, line: 1 },
+          end: { column: 15, line: 1 },
+        },
+      },
+      id: Identifier {
+        type: "Identifier",
+        name: "A",
+
+        range: [7, 8],
+        loc: {
+          start: { column: 7, line: 1 },
+          end: { column: 8, line: 1 },
+        },
+      },
+
+      range: [0, 15],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 15, line: 1 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 16],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-id-qualified-name/snapshots/2-TSESTree-Tokens.shot b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-id-qualified-name/snapshots/2-TSESTree-Tokens.shot
new file mode 100644
index 000000000000..70d7cd911e17
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-id-qualified-name/snapshots/2-TSESTree-Tokens.shot
@@ -0,0 +1,86 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSModuleDeclaration module-id-qualified-name TSESTree - Tokens 1`] = `
+Array [
+  Identifier {
+    type: "Identifier",
+    value: "module",
+
+    range: [0, 6],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 6, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "A",
+
+    range: [7, 8],
+    loc: {
+      start: { column: 7, line: 1 },
+      end: { column: 8, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ".",
+
+    range: [8, 9],
+    loc: {
+      start: { column: 8, line: 1 },
+      end: { column: 9, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "B",
+
+    range: [9, 10],
+    loc: {
+      start: { column: 9, line: 1 },
+      end: { column: 10, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ".",
+
+    range: [10, 11],
+    loc: {
+      start: { column: 10, line: 1 },
+      end: { column: 11, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "C",
+
+    range: [11, 12],
+    loc: {
+      start: { column: 11, line: 1 },
+      end: { column: 12, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "{",
+
+    range: [13, 14],
+    loc: {
+      start: { column: 13, line: 1 },
+      end: { column: 14, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "}",
+
+    range: [14, 15],
+    loc: {
+      start: { column: 14, line: 1 },
+      end: { column: 15, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-id-qualified-name/snapshots/3-Babel-AST.shot b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-id-qualified-name/snapshots/3-Babel-AST.shot
new file mode 100644
index 000000000000..c6af56a98835
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-id-qualified-name/snapshots/3-Babel-AST.shot
@@ -0,0 +1,83 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSModuleDeclaration module-id-qualified-name Babel - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    TSModuleDeclaration {
+      type: "TSModuleDeclaration",
+      body: TSModuleDeclaration {
+        type: "TSModuleDeclaration",
+        body: TSModuleDeclaration {
+          type: "TSModuleDeclaration",
+          body: TSModuleBlock {
+            type: "TSModuleBlock",
+            body: Array [],
+
+            range: [13, 15],
+            loc: {
+              start: { column: 13, line: 1 },
+              end: { column: 15, line: 1 },
+            },
+          },
+          id: Identifier {
+            type: "Identifier",
+            name: "C",
+
+            range: [11, 12],
+            loc: {
+              start: { column: 11, line: 1 },
+              end: { column: 12, line: 1 },
+            },
+          },
+
+          range: [11, 15],
+          loc: {
+            start: { column: 11, line: 1 },
+            end: { column: 15, line: 1 },
+          },
+        },
+        id: Identifier {
+          type: "Identifier",
+          name: "B",
+
+          range: [9, 10],
+          loc: {
+            start: { column: 9, line: 1 },
+            end: { column: 10, line: 1 },
+          },
+        },
+
+        range: [9, 15],
+        loc: {
+          start: { column: 9, line: 1 },
+          end: { column: 15, line: 1 },
+        },
+      },
+      id: Identifier {
+        type: "Identifier",
+        name: "A",
+
+        range: [7, 8],
+        loc: {
+          start: { column: 7, line: 1 },
+          end: { column: 8, line: 1 },
+        },
+      },
+
+      range: [0, 15],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 15, line: 1 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 16],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-id-qualified-name/snapshots/4-Babel-Tokens.shot b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-id-qualified-name/snapshots/4-Babel-Tokens.shot
new file mode 100644
index 000000000000..b03c2f7b5a82
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-id-qualified-name/snapshots/4-Babel-Tokens.shot
@@ -0,0 +1,86 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSModuleDeclaration module-id-qualified-name Babel - Tokens 1`] = `
+Array [
+  Identifier {
+    type: "Identifier",
+    value: "module",
+
+    range: [0, 6],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 6, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "A",
+
+    range: [7, 8],
+    loc: {
+      start: { column: 7, line: 1 },
+      end: { column: 8, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ".",
+
+    range: [8, 9],
+    loc: {
+      start: { column: 8, line: 1 },
+      end: { column: 9, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "B",
+
+    range: [9, 10],
+    loc: {
+      start: { column: 9, line: 1 },
+      end: { column: 10, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ".",
+
+    range: [10, 11],
+    loc: {
+      start: { column: 10, line: 1 },
+      end: { column: 11, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "C",
+
+    range: [11, 12],
+    loc: {
+      start: { column: 11, line: 1 },
+      end: { column: 12, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "{",
+
+    range: [13, 14],
+    loc: {
+      start: { column: 13, line: 1 },
+      end: { column: 14, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "}",
+
+    range: [14, 15],
+    loc: {
+      start: { column: 14, line: 1 },
+      end: { column: 15, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-id-qualified-name/snapshots/5-AST-Alignment-AST.shot b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-id-qualified-name/snapshots/5-AST-Alignment-AST.shot
new file mode 100644
index 000000000000..d442f261db29
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-id-qualified-name/snapshots/5-AST-Alignment-AST.shot
@@ -0,0 +1,6 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSModuleDeclaration module-id-qualified-name AST Alignment - AST 1`] = `
+"Snapshot Diff:
+Compared values have no visual difference."
+`;
diff --git a/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-id-qualified-name/snapshots/6-AST-Alignment-Tokens.shot b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-id-qualified-name/snapshots/6-AST-Alignment-Tokens.shot
new file mode 100644
index 000000000000..68241771f7c5
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/module-id-qualified-name/snapshots/6-AST-Alignment-Tokens.shot
@@ -0,0 +1,6 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSModuleDeclaration module-id-qualified-name AST Alignment - Token 1`] = `
+"Snapshot Diff:
+Compared values have no visual difference."
+`;
diff --git a/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/namespace-declare/fixture.ts b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/namespace-declare/fixture.ts
new file mode 100644
index 000000000000..ebc35823e75d
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/namespace-declare/fixture.ts
@@ -0,0 +1 @@
+declare namespace F {}
diff --git a/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/namespace-declare/snapshots/1-TSESTree-AST.shot b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/namespace-declare/snapshots/1-TSESTree-AST.shot
new file mode 100644
index 000000000000..c373a655222a
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/namespace-declare/snapshots/1-TSESTree-AST.shot
@@ -0,0 +1,46 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSModuleDeclaration namespace-declare TSESTree - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    TSModuleDeclaration {
+      type: "TSModuleDeclaration",
+      body: TSModuleBlock {
+        type: "TSModuleBlock",
+        body: Array [],
+
+        range: [20, 22],
+        loc: {
+          start: { column: 20, line: 1 },
+          end: { column: 22, line: 1 },
+        },
+      },
+      declare: true,
+      id: Identifier {
+        type: "Identifier",
+        name: "F",
+
+        range: [18, 19],
+        loc: {
+          start: { column: 18, line: 1 },
+          end: { column: 19, line: 1 },
+        },
+      },
+
+      range: [0, 22],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 22, line: 1 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 23],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/namespace-declare/snapshots/2-TSESTree-Tokens.shot b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/namespace-declare/snapshots/2-TSESTree-Tokens.shot
new file mode 100644
index 000000000000..18d298125dde
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/namespace-declare/snapshots/2-TSESTree-Tokens.shot
@@ -0,0 +1,56 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSModuleDeclaration namespace-declare TSESTree - Tokens 1`] = `
+Array [
+  Identifier {
+    type: "Identifier",
+    value: "declare",
+
+    range: [0, 7],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 7, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "namespace",
+
+    range: [8, 17],
+    loc: {
+      start: { column: 8, line: 1 },
+      end: { column: 17, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "F",
+
+    range: [18, 19],
+    loc: {
+      start: { column: 18, line: 1 },
+      end: { column: 19, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "{",
+
+    range: [20, 21],
+    loc: {
+      start: { column: 20, line: 1 },
+      end: { column: 21, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "}",
+
+    range: [21, 22],
+    loc: {
+      start: { column: 21, line: 1 },
+      end: { column: 22, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/namespace-declare/snapshots/3-Babel-AST.shot b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/namespace-declare/snapshots/3-Babel-AST.shot
new file mode 100644
index 000000000000..269366508604
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/namespace-declare/snapshots/3-Babel-AST.shot
@@ -0,0 +1,46 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSModuleDeclaration namespace-declare Babel - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    TSModuleDeclaration {
+      type: "TSModuleDeclaration",
+      body: TSModuleBlock {
+        type: "TSModuleBlock",
+        body: Array [],
+
+        range: [20, 22],
+        loc: {
+          start: { column: 20, line: 1 },
+          end: { column: 22, line: 1 },
+        },
+      },
+      declare: true,
+      id: Identifier {
+        type: "Identifier",
+        name: "F",
+
+        range: [18, 19],
+        loc: {
+          start: { column: 18, line: 1 },
+          end: { column: 19, line: 1 },
+        },
+      },
+
+      range: [0, 22],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 22, line: 1 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 23],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/namespace-declare/snapshots/4-Babel-Tokens.shot b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/namespace-declare/snapshots/4-Babel-Tokens.shot
new file mode 100644
index 000000000000..374070330ed0
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/namespace-declare/snapshots/4-Babel-Tokens.shot
@@ -0,0 +1,56 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSModuleDeclaration namespace-declare Babel - Tokens 1`] = `
+Array [
+  Identifier {
+    type: "Identifier",
+    value: "declare",
+
+    range: [0, 7],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 7, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "namespace",
+
+    range: [8, 17],
+    loc: {
+      start: { column: 8, line: 1 },
+      end: { column: 17, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "F",
+
+    range: [18, 19],
+    loc: {
+      start: { column: 18, line: 1 },
+      end: { column: 19, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "{",
+
+    range: [20, 21],
+    loc: {
+      start: { column: 20, line: 1 },
+      end: { column: 21, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "}",
+
+    range: [21, 22],
+    loc: {
+      start: { column: 21, line: 1 },
+      end: { column: 22, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/namespace-declare/snapshots/5-AST-Alignment-AST.shot b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/namespace-declare/snapshots/5-AST-Alignment-AST.shot
new file mode 100644
index 000000000000..614b9695a3cf
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/namespace-declare/snapshots/5-AST-Alignment-AST.shot
@@ -0,0 +1,6 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSModuleDeclaration namespace-declare AST Alignment - AST 1`] = `
+"Snapshot Diff:
+Compared values have no visual difference."
+`;
diff --git a/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/namespace-declare/snapshots/6-AST-Alignment-Tokens.shot b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/namespace-declare/snapshots/6-AST-Alignment-Tokens.shot
new file mode 100644
index 000000000000..1e9fda98a787
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/namespace-declare/snapshots/6-AST-Alignment-Tokens.shot
@@ -0,0 +1,6 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSModuleDeclaration namespace-declare AST Alignment - Token 1`] = `
+"Snapshot Diff:
+Compared values have no visual difference."
+`;
diff --git a/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/namespace-id-identifier/fixture.ts b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/namespace-id-identifier/fixture.ts
new file mode 100644
index 000000000000..fb1741b05b2d
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/namespace-id-identifier/fixture.ts
@@ -0,0 +1 @@
+namespace F {}
diff --git a/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/namespace-id-identifier/snapshots/1-TSESTree-AST.shot b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/namespace-id-identifier/snapshots/1-TSESTree-AST.shot
new file mode 100644
index 000000000000..e6303e2d3edc
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/namespace-id-identifier/snapshots/1-TSESTree-AST.shot
@@ -0,0 +1,45 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSModuleDeclaration namespace-id-identifier TSESTree - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    TSModuleDeclaration {
+      type: "TSModuleDeclaration",
+      body: TSModuleBlock {
+        type: "TSModuleBlock",
+        body: Array [],
+
+        range: [12, 14],
+        loc: {
+          start: { column: 12, line: 1 },
+          end: { column: 14, line: 1 },
+        },
+      },
+      id: Identifier {
+        type: "Identifier",
+        name: "F",
+
+        range: [10, 11],
+        loc: {
+          start: { column: 10, line: 1 },
+          end: { column: 11, line: 1 },
+        },
+      },
+
+      range: [0, 14],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 14, line: 1 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 15],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/namespace-id-identifier/snapshots/2-TSESTree-Tokens.shot b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/namespace-id-identifier/snapshots/2-TSESTree-Tokens.shot
new file mode 100644
index 000000000000..15cd21e3ad5d
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/namespace-id-identifier/snapshots/2-TSESTree-Tokens.shot
@@ -0,0 +1,46 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSModuleDeclaration namespace-id-identifier TSESTree - Tokens 1`] = `
+Array [
+  Identifier {
+    type: "Identifier",
+    value: "namespace",
+
+    range: [0, 9],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 9, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "F",
+
+    range: [10, 11],
+    loc: {
+      start: { column: 10, line: 1 },
+      end: { column: 11, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "{",
+
+    range: [12, 13],
+    loc: {
+      start: { column: 12, line: 1 },
+      end: { column: 13, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "}",
+
+    range: [13, 14],
+    loc: {
+      start: { column: 13, line: 1 },
+      end: { column: 14, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/namespace-id-identifier/snapshots/3-Babel-AST.shot b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/namespace-id-identifier/snapshots/3-Babel-AST.shot
new file mode 100644
index 000000000000..2e47480e0447
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/namespace-id-identifier/snapshots/3-Babel-AST.shot
@@ -0,0 +1,45 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSModuleDeclaration namespace-id-identifier Babel - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    TSModuleDeclaration {
+      type: "TSModuleDeclaration",
+      body: TSModuleBlock {
+        type: "TSModuleBlock",
+        body: Array [],
+
+        range: [12, 14],
+        loc: {
+          start: { column: 12, line: 1 },
+          end: { column: 14, line: 1 },
+        },
+      },
+      id: Identifier {
+        type: "Identifier",
+        name: "F",
+
+        range: [10, 11],
+        loc: {
+          start: { column: 10, line: 1 },
+          end: { column: 11, line: 1 },
+        },
+      },
+
+      range: [0, 14],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 14, line: 1 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 15],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/namespace-id-identifier/snapshots/4-Babel-Tokens.shot b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/namespace-id-identifier/snapshots/4-Babel-Tokens.shot
new file mode 100644
index 000000000000..1fb07e00228d
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/namespace-id-identifier/snapshots/4-Babel-Tokens.shot
@@ -0,0 +1,46 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSModuleDeclaration namespace-id-identifier Babel - Tokens 1`] = `
+Array [
+  Identifier {
+    type: "Identifier",
+    value: "namespace",
+
+    range: [0, 9],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 9, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "F",
+
+    range: [10, 11],
+    loc: {
+      start: { column: 10, line: 1 },
+      end: { column: 11, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "{",
+
+    range: [12, 13],
+    loc: {
+      start: { column: 12, line: 1 },
+      end: { column: 13, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "}",
+
+    range: [13, 14],
+    loc: {
+      start: { column: 13, line: 1 },
+      end: { column: 14, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/namespace-id-identifier/snapshots/5-AST-Alignment-AST.shot b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/namespace-id-identifier/snapshots/5-AST-Alignment-AST.shot
new file mode 100644
index 000000000000..a0aa056256bc
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/namespace-id-identifier/snapshots/5-AST-Alignment-AST.shot
@@ -0,0 +1,6 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSModuleDeclaration namespace-id-identifier AST Alignment - AST 1`] = `
+"Snapshot Diff:
+Compared values have no visual difference."
+`;
diff --git a/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/namespace-id-identifier/snapshots/6-AST-Alignment-Tokens.shot b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/namespace-id-identifier/snapshots/6-AST-Alignment-Tokens.shot
new file mode 100644
index 000000000000..112e01d377c9
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/namespace-id-identifier/snapshots/6-AST-Alignment-Tokens.shot
@@ -0,0 +1,6 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSModuleDeclaration namespace-id-identifier AST Alignment - Token 1`] = `
+"Snapshot Diff:
+Compared values have no visual difference."
+`;
diff --git a/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/namespace-id-qualified-name/fixture.ts b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/namespace-id-qualified-name/fixture.ts
new file mode 100644
index 000000000000..c7c1b751f8da
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/namespace-id-qualified-name/fixture.ts
@@ -0,0 +1 @@
+namespace A.B.C {}
diff --git a/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/namespace-id-qualified-name/snapshots/1-TSESTree-AST.shot b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/namespace-id-qualified-name/snapshots/1-TSESTree-AST.shot
new file mode 100644
index 000000000000..98cd5bbe8176
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/namespace-id-qualified-name/snapshots/1-TSESTree-AST.shot
@@ -0,0 +1,83 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSModuleDeclaration namespace-id-qualified-name TSESTree - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    TSModuleDeclaration {
+      type: "TSModuleDeclaration",
+      body: TSModuleDeclaration {
+        type: "TSModuleDeclaration",
+        body: TSModuleDeclaration {
+          type: "TSModuleDeclaration",
+          body: TSModuleBlock {
+            type: "TSModuleBlock",
+            body: Array [],
+
+            range: [16, 18],
+            loc: {
+              start: { column: 16, line: 1 },
+              end: { column: 18, line: 1 },
+            },
+          },
+          id: Identifier {
+            type: "Identifier",
+            name: "C",
+
+            range: [14, 15],
+            loc: {
+              start: { column: 14, line: 1 },
+              end: { column: 15, line: 1 },
+            },
+          },
+
+          range: [14, 18],
+          loc: {
+            start: { column: 14, line: 1 },
+            end: { column: 18, line: 1 },
+          },
+        },
+        id: Identifier {
+          type: "Identifier",
+          name: "B",
+
+          range: [12, 13],
+          loc: {
+            start: { column: 12, line: 1 },
+            end: { column: 13, line: 1 },
+          },
+        },
+
+        range: [12, 18],
+        loc: {
+          start: { column: 12, line: 1 },
+          end: { column: 18, line: 1 },
+        },
+      },
+      id: Identifier {
+        type: "Identifier",
+        name: "A",
+
+        range: [10, 11],
+        loc: {
+          start: { column: 10, line: 1 },
+          end: { column: 11, line: 1 },
+        },
+      },
+
+      range: [0, 18],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 18, line: 1 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 19],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/namespace-id-qualified-name/snapshots/2-TSESTree-Tokens.shot b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/namespace-id-qualified-name/snapshots/2-TSESTree-Tokens.shot
new file mode 100644
index 000000000000..fcd5df00be87
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/namespace-id-qualified-name/snapshots/2-TSESTree-Tokens.shot
@@ -0,0 +1,86 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSModuleDeclaration namespace-id-qualified-name TSESTree - Tokens 1`] = `
+Array [
+  Identifier {
+    type: "Identifier",
+    value: "namespace",
+
+    range: [0, 9],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 9, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "A",
+
+    range: [10, 11],
+    loc: {
+      start: { column: 10, line: 1 },
+      end: { column: 11, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ".",
+
+    range: [11, 12],
+    loc: {
+      start: { column: 11, line: 1 },
+      end: { column: 12, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "B",
+
+    range: [12, 13],
+    loc: {
+      start: { column: 12, line: 1 },
+      end: { column: 13, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ".",
+
+    range: [13, 14],
+    loc: {
+      start: { column: 13, line: 1 },
+      end: { column: 14, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "C",
+
+    range: [14, 15],
+    loc: {
+      start: { column: 14, line: 1 },
+      end: { column: 15, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "{",
+
+    range: [16, 17],
+    loc: {
+      start: { column: 16, line: 1 },
+      end: { column: 17, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "}",
+
+    range: [17, 18],
+    loc: {
+      start: { column: 17, line: 1 },
+      end: { column: 18, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/namespace-id-qualified-name/snapshots/3-Babel-AST.shot b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/namespace-id-qualified-name/snapshots/3-Babel-AST.shot
new file mode 100644
index 000000000000..569b49fb3274
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/namespace-id-qualified-name/snapshots/3-Babel-AST.shot
@@ -0,0 +1,83 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSModuleDeclaration namespace-id-qualified-name Babel - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    TSModuleDeclaration {
+      type: "TSModuleDeclaration",
+      body: TSModuleDeclaration {
+        type: "TSModuleDeclaration",
+        body: TSModuleDeclaration {
+          type: "TSModuleDeclaration",
+          body: TSModuleBlock {
+            type: "TSModuleBlock",
+            body: Array [],
+
+            range: [16, 18],
+            loc: {
+              start: { column: 16, line: 1 },
+              end: { column: 18, line: 1 },
+            },
+          },
+          id: Identifier {
+            type: "Identifier",
+            name: "C",
+
+            range: [14, 15],
+            loc: {
+              start: { column: 14, line: 1 },
+              end: { column: 15, line: 1 },
+            },
+          },
+
+          range: [14, 18],
+          loc: {
+            start: { column: 14, line: 1 },
+            end: { column: 18, line: 1 },
+          },
+        },
+        id: Identifier {
+          type: "Identifier",
+          name: "B",
+
+          range: [12, 13],
+          loc: {
+            start: { column: 12, line: 1 },
+            end: { column: 13, line: 1 },
+          },
+        },
+
+        range: [12, 18],
+        loc: {
+          start: { column: 12, line: 1 },
+          end: { column: 18, line: 1 },
+        },
+      },
+      id: Identifier {
+        type: "Identifier",
+        name: "A",
+
+        range: [10, 11],
+        loc: {
+          start: { column: 10, line: 1 },
+          end: { column: 11, line: 1 },
+        },
+      },
+
+      range: [0, 18],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 18, line: 1 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 19],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/namespace-id-qualified-name/snapshots/4-Babel-Tokens.shot b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/namespace-id-qualified-name/snapshots/4-Babel-Tokens.shot
new file mode 100644
index 000000000000..8f3b974a3ab1
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/namespace-id-qualified-name/snapshots/4-Babel-Tokens.shot
@@ -0,0 +1,86 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSModuleDeclaration namespace-id-qualified-name Babel - Tokens 1`] = `
+Array [
+  Identifier {
+    type: "Identifier",
+    value: "namespace",
+
+    range: [0, 9],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 9, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "A",
+
+    range: [10, 11],
+    loc: {
+      start: { column: 10, line: 1 },
+      end: { column: 11, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ".",
+
+    range: [11, 12],
+    loc: {
+      start: { column: 11, line: 1 },
+      end: { column: 12, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "B",
+
+    range: [12, 13],
+    loc: {
+      start: { column: 12, line: 1 },
+      end: { column: 13, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ".",
+
+    range: [13, 14],
+    loc: {
+      start: { column: 13, line: 1 },
+      end: { column: 14, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "C",
+
+    range: [14, 15],
+    loc: {
+      start: { column: 14, line: 1 },
+      end: { column: 15, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "{",
+
+    range: [16, 17],
+    loc: {
+      start: { column: 16, line: 1 },
+      end: { column: 17, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "}",
+
+    range: [17, 18],
+    loc: {
+      start: { column: 17, line: 1 },
+      end: { column: 18, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/namespace-id-qualified-name/snapshots/5-AST-Alignment-AST.shot b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/namespace-id-qualified-name/snapshots/5-AST-Alignment-AST.shot
new file mode 100644
index 000000000000..a7a16eee58a5
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/namespace-id-qualified-name/snapshots/5-AST-Alignment-AST.shot
@@ -0,0 +1,6 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSModuleDeclaration namespace-id-qualified-name AST Alignment - AST 1`] = `
+"Snapshot Diff:
+Compared values have no visual difference."
+`;
diff --git a/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/namespace-id-qualified-name/snapshots/6-AST-Alignment-Tokens.shot b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/namespace-id-qualified-name/snapshots/6-AST-Alignment-Tokens.shot
new file mode 100644
index 000000000000..1e60c8843aae
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSModuleDeclaration/fixtures/namespace-id-qualified-name/snapshots/6-AST-Alignment-Tokens.shot
@@ -0,0 +1,6 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSModuleDeclaration namespace-id-qualified-name AST Alignment - Token 1`] = `
+"Snapshot Diff:
+Compared values have no visual difference."
+`;
diff --git a/packages/ast-spec/src/declaration/TSModuleDeclaration/spec.ts b/packages/ast-spec/src/declaration/TSModuleDeclaration/spec.ts
index ac63e52a5938..e077d1648e1f 100644
--- a/packages/ast-spec/src/declaration/TSModuleDeclaration/spec.ts
+++ b/packages/ast-spec/src/declaration/TSModuleDeclaration/spec.ts
@@ -7,11 +7,24 @@ import type { Modifier } from '../../unions/Modifier';
 
 export interface TSModuleDeclaration extends BaseNode {
   type: AST_NODE_TYPES.TSModuleDeclaration;
+  /**
+   * The name of the module
+   * ```
+   * namespace A {}
+   * namespace A.B.C {}
+   * module 'a' {}
+   * ```
+   */
   id: Identifier | Literal;
+  /**
+   * The body of the module.
+   * This can only be `undefined` for the code `declare module 'mod';`
+   * This will be a `TSModuleDeclaration` if the name is "nested" (`Foo.Bar`).
+   */
   body?:
     | TSModuleBlock
     /*
-    TODO - we currently emit this due to bad parser handling of nested modules
+    TODO(#4966) - we currently emit this due to bad parser handling of nested modules
     namespace Foo.Bar {}
     ^^^^^^^^^^^^^^^^^^^^ TSModuleDeclaration
                   ^^^^^^ TSModuleDeclaration
@@ -20,7 +33,22 @@ export interface TSModuleDeclaration extends BaseNode {
     This should instead emit a TSQualifiedName for the `id` and not emit an inner TSModuleDeclaration
     */
     | TSModuleDeclaration;
+  /**
+   * Whether this is a global declaration
+   * ```
+   * declare global {}
+   * ```
+   */
+  // TODO(#5020) - make this `false` if not `global`
   global?: boolean;
+  /**
+   * Whether the module is `declare`d
+   * ```
+   * declare namespace F {}
+   * ```
+   */
+  // TODO(#5020) - make this `false` if it is not `declare`d
   declare?: boolean;
+  // TODO(#4759) - breaking change remove this
   modifiers?: Modifier[];
 }
diff --git a/packages/ast-spec/src/declaration/TSNamespaceExportDeclaration/fixtures/_error_/missing-id/fixture.ts b/packages/ast-spec/src/declaration/TSNamespaceExportDeclaration/fixtures/_error_/missing-id/fixture.ts
new file mode 100644
index 000000000000..bbcfe5795de2
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSNamespaceExportDeclaration/fixtures/_error_/missing-id/fixture.ts
@@ -0,0 +1 @@
+export as namespace;
diff --git a/packages/ast-spec/src/declaration/TSNamespaceExportDeclaration/fixtures/_error_/missing-id/snapshots/1-TSESTree-Error.shot b/packages/ast-spec/src/declaration/TSNamespaceExportDeclaration/fixtures/_error_/missing-id/snapshots/1-TSESTree-Error.shot
new file mode 100644
index 000000000000..e47c9aa7c254
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSNamespaceExportDeclaration/fixtures/_error_/missing-id/snapshots/1-TSESTree-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSNamespaceExportDeclaration _error_ missing-id TSESTree - Error 1`] = `[TSError: Identifier expected.]`;
diff --git a/packages/ast-spec/src/declaration/TSNamespaceExportDeclaration/fixtures/_error_/missing-id/snapshots/2-Babel-Error.shot b/packages/ast-spec/src/declaration/TSNamespaceExportDeclaration/fixtures/_error_/missing-id/snapshots/2-Babel-Error.shot
new file mode 100644
index 000000000000..300850581d62
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSNamespaceExportDeclaration/fixtures/_error_/missing-id/snapshots/2-Babel-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSNamespaceExportDeclaration _error_ missing-id Babel - Error 1`] = `[SyntaxError: Unexpected token (1:19)]`;
diff --git a/packages/ast-spec/src/declaration/TSNamespaceExportDeclaration/fixtures/_error_/missing-id/snapshots/3-Alignment-Error.shot b/packages/ast-spec/src/declaration/TSNamespaceExportDeclaration/fixtures/_error_/missing-id/snapshots/3-Alignment-Error.shot
new file mode 100644
index 000000000000..0b5d774603fd
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSNamespaceExportDeclaration/fixtures/_error_/missing-id/snapshots/3-Alignment-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSNamespaceExportDeclaration _error_ missing-id Error Alignment 1`] = `"Both errored"`;
diff --git a/packages/ast-spec/src/declaration/TSNamespaceExportDeclaration/fixtures/_error_/non-identifier-name/fixture.ts b/packages/ast-spec/src/declaration/TSNamespaceExportDeclaration/fixtures/_error_/non-identifier-name/fixture.ts
new file mode 100644
index 000000000000..a8878e61afef
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSNamespaceExportDeclaration/fixtures/_error_/non-identifier-name/fixture.ts
@@ -0,0 +1 @@
+export as namespace 1;
diff --git a/packages/ast-spec/src/declaration/TSNamespaceExportDeclaration/fixtures/_error_/non-identifier-name/snapshots/1-TSESTree-Error.shot b/packages/ast-spec/src/declaration/TSNamespaceExportDeclaration/fixtures/_error_/non-identifier-name/snapshots/1-TSESTree-Error.shot
new file mode 100644
index 000000000000..3e11b4700297
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSNamespaceExportDeclaration/fixtures/_error_/non-identifier-name/snapshots/1-TSESTree-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSNamespaceExportDeclaration _error_ non-identifier-name TSESTree - Error 1`] = `[TSError: Identifier expected.]`;
diff --git a/packages/ast-spec/src/declaration/TSNamespaceExportDeclaration/fixtures/_error_/non-identifier-name/snapshots/2-Babel-Error.shot b/packages/ast-spec/src/declaration/TSNamespaceExportDeclaration/fixtures/_error_/non-identifier-name/snapshots/2-Babel-Error.shot
new file mode 100644
index 000000000000..f2641cc64de2
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSNamespaceExportDeclaration/fixtures/_error_/non-identifier-name/snapshots/2-Babel-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSNamespaceExportDeclaration _error_ non-identifier-name Babel - Error 1`] = `[SyntaxError: Unexpected token (1:20)]`;
diff --git a/packages/ast-spec/src/declaration/TSNamespaceExportDeclaration/fixtures/_error_/non-identifier-name/snapshots/3-Alignment-Error.shot b/packages/ast-spec/src/declaration/TSNamespaceExportDeclaration/fixtures/_error_/non-identifier-name/snapshots/3-Alignment-Error.shot
new file mode 100644
index 000000000000..defe8a17bba2
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSNamespaceExportDeclaration/fixtures/_error_/non-identifier-name/snapshots/3-Alignment-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSNamespaceExportDeclaration _error_ non-identifier-name Error Alignment 1`] = `"Both errored"`;
diff --git a/packages/ast-spec/src/declaration/TSNamespaceExportDeclaration/fixtures/valid/fixture.ts b/packages/ast-spec/src/declaration/TSNamespaceExportDeclaration/fixtures/valid/fixture.ts
new file mode 100644
index 000000000000..ff8bbadf397d
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSNamespaceExportDeclaration/fixtures/valid/fixture.ts
@@ -0,0 +1 @@
+export as namespace a;
diff --git a/packages/ast-spec/src/declaration/TSNamespaceExportDeclaration/fixtures/valid/snapshots/1-TSESTree-AST.shot b/packages/ast-spec/src/declaration/TSNamespaceExportDeclaration/fixtures/valid/snapshots/1-TSESTree-AST.shot
new file mode 100644
index 000000000000..914df1fad854
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSNamespaceExportDeclaration/fixtures/valid/snapshots/1-TSESTree-AST.shot
@@ -0,0 +1,35 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSNamespaceExportDeclaration valid TSESTree - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    TSNamespaceExportDeclaration {
+      type: "TSNamespaceExportDeclaration",
+      id: Identifier {
+        type: "Identifier",
+        name: "a",
+
+        range: [20, 21],
+        loc: {
+          start: { column: 20, line: 1 },
+          end: { column: 21, line: 1 },
+        },
+      },
+
+      range: [0, 22],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 22, line: 1 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 23],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/TSNamespaceExportDeclaration/fixtures/valid/snapshots/2-TSESTree-Tokens.shot b/packages/ast-spec/src/declaration/TSNamespaceExportDeclaration/fixtures/valid/snapshots/2-TSESTree-Tokens.shot
new file mode 100644
index 000000000000..8399bbd3d1d7
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSNamespaceExportDeclaration/fixtures/valid/snapshots/2-TSESTree-Tokens.shot
@@ -0,0 +1,56 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSNamespaceExportDeclaration valid TSESTree - Tokens 1`] = `
+Array [
+  Keyword {
+    type: "Keyword",
+    value: "export",
+
+    range: [0, 6],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 6, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "as",
+
+    range: [7, 9],
+    loc: {
+      start: { column: 7, line: 1 },
+      end: { column: 9, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "namespace",
+
+    range: [10, 19],
+    loc: {
+      start: { column: 10, line: 1 },
+      end: { column: 19, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "a",
+
+    range: [20, 21],
+    loc: {
+      start: { column: 20, line: 1 },
+      end: { column: 21, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ";",
+
+    range: [21, 22],
+    loc: {
+      start: { column: 21, line: 1 },
+      end: { column: 22, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/TSNamespaceExportDeclaration/fixtures/valid/snapshots/3-Babel-AST.shot b/packages/ast-spec/src/declaration/TSNamespaceExportDeclaration/fixtures/valid/snapshots/3-Babel-AST.shot
new file mode 100644
index 000000000000..c3861bcab7bd
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSNamespaceExportDeclaration/fixtures/valid/snapshots/3-Babel-AST.shot
@@ -0,0 +1,35 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSNamespaceExportDeclaration valid Babel - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    TSNamespaceExportDeclaration {
+      type: "TSNamespaceExportDeclaration",
+      id: Identifier {
+        type: "Identifier",
+        name: "a",
+
+        range: [20, 21],
+        loc: {
+          start: { column: 20, line: 1 },
+          end: { column: 21, line: 1 },
+        },
+      },
+
+      range: [0, 22],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 22, line: 1 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 23],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/TSNamespaceExportDeclaration/fixtures/valid/snapshots/4-Babel-Tokens.shot b/packages/ast-spec/src/declaration/TSNamespaceExportDeclaration/fixtures/valid/snapshots/4-Babel-Tokens.shot
new file mode 100644
index 000000000000..dfe3eae2d2ac
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSNamespaceExportDeclaration/fixtures/valid/snapshots/4-Babel-Tokens.shot
@@ -0,0 +1,56 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSNamespaceExportDeclaration valid Babel - Tokens 1`] = `
+Array [
+  Keyword {
+    type: "Keyword",
+    value: "export",
+
+    range: [0, 6],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 6, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "as",
+
+    range: [7, 9],
+    loc: {
+      start: { column: 7, line: 1 },
+      end: { column: 9, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "namespace",
+
+    range: [10, 19],
+    loc: {
+      start: { column: 10, line: 1 },
+      end: { column: 19, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "a",
+
+    range: [20, 21],
+    loc: {
+      start: { column: 20, line: 1 },
+      end: { column: 21, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ";",
+
+    range: [21, 22],
+    loc: {
+      start: { column: 21, line: 1 },
+      end: { column: 22, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/TSNamespaceExportDeclaration/fixtures/valid/snapshots/5-AST-Alignment-AST.shot b/packages/ast-spec/src/declaration/TSNamespaceExportDeclaration/fixtures/valid/snapshots/5-AST-Alignment-AST.shot
new file mode 100644
index 000000000000..6cd11e1f4b30
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSNamespaceExportDeclaration/fixtures/valid/snapshots/5-AST-Alignment-AST.shot
@@ -0,0 +1,6 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSNamespaceExportDeclaration valid AST Alignment - AST 1`] = `
+"Snapshot Diff:
+Compared values have no visual difference."
+`;
diff --git a/packages/ast-spec/src/declaration/TSNamespaceExportDeclaration/fixtures/valid/snapshots/6-AST-Alignment-Tokens.shot b/packages/ast-spec/src/declaration/TSNamespaceExportDeclaration/fixtures/valid/snapshots/6-AST-Alignment-Tokens.shot
new file mode 100644
index 000000000000..c7d4f1d7315f
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSNamespaceExportDeclaration/fixtures/valid/snapshots/6-AST-Alignment-Tokens.shot
@@ -0,0 +1,6 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSNamespaceExportDeclaration valid AST Alignment - Token 1`] = `
+"Snapshot Diff:
+Compared values have no visual difference."
+`;
diff --git a/packages/ast-spec/src/declaration/TSNamespaceExportDeclaration/spec.ts b/packages/ast-spec/src/declaration/TSNamespaceExportDeclaration/spec.ts
index 6853d4a28544..da63cca2ac69 100644
--- a/packages/ast-spec/src/declaration/TSNamespaceExportDeclaration/spec.ts
+++ b/packages/ast-spec/src/declaration/TSNamespaceExportDeclaration/spec.ts
@@ -4,5 +4,8 @@ import type { Identifier } from '../../expression/Identifier/spec';
 
 export interface TSNamespaceExportDeclaration extends BaseNode {
   type: AST_NODE_TYPES.TSNamespaceExportDeclaration;
+  /**
+   * The name the global variable being exported to
+   */
   id: Identifier;
 }
diff --git a/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/_error_/missing-type-parameter/fixture.ts b/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/_error_/missing-type-parameter/fixture.ts
new file mode 100644
index 000000000000..3bd6bc6c6053
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/_error_/missing-type-parameter/fixture.ts
@@ -0,0 +1 @@
+type T<> = 1;
diff --git a/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/_error_/missing-type-parameter/snapshots/1-TSESTree-Error.shot b/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/_error_/missing-type-parameter/snapshots/1-TSESTree-Error.shot
new file mode 100644
index 000000000000..9902528eb41d
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/_error_/missing-type-parameter/snapshots/1-TSESTree-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSTypeAliasDeclaration _error_ missing-type-parameter TSESTree - Error 1`] = `"NO ERROR"`;
diff --git a/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/_error_/missing-type-parameter/snapshots/2-Babel-Error.shot b/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/_error_/missing-type-parameter/snapshots/2-Babel-Error.shot
new file mode 100644
index 000000000000..b18ec532458e
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/_error_/missing-type-parameter/snapshots/2-Babel-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSTypeAliasDeclaration _error_ missing-type-parameter Babel - Error 1`] = `[SyntaxError: Type parameter list cannot be empty. (1:6)]`;
diff --git a/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/_error_/missing-type-parameter/snapshots/3-Alignment-Error.shot b/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/_error_/missing-type-parameter/snapshots/3-Alignment-Error.shot
new file mode 100644
index 000000000000..99587163b896
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/_error_/missing-type-parameter/snapshots/3-Alignment-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSTypeAliasDeclaration _error_ missing-type-parameter Error Alignment 1`] = `"Babel errored but TSESTree didn't"`;
diff --git a/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/_error_/non-identifier-name/fixture.ts b/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/_error_/non-identifier-name/fixture.ts
new file mode 100644
index 000000000000..533f0b183cf5
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/_error_/non-identifier-name/fixture.ts
@@ -0,0 +1 @@
+type 1 = 2;
diff --git a/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/_error_/non-identifier-name/snapshots/1-TSESTree-Error.shot b/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/_error_/non-identifier-name/snapshots/1-TSESTree-Error.shot
new file mode 100644
index 000000000000..7eaf3f0bba48
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/_error_/non-identifier-name/snapshots/1-TSESTree-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSTypeAliasDeclaration _error_ non-identifier-name TSESTree - Error 1`] = `[TSError: Type alias name cannot be '1'.]`;
diff --git a/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/_error_/non-identifier-name/snapshots/2-Babel-Error.shot b/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/_error_/non-identifier-name/snapshots/2-Babel-Error.shot
new file mode 100644
index 000000000000..f7c419205f79
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/_error_/non-identifier-name/snapshots/2-Babel-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSTypeAliasDeclaration _error_ non-identifier-name Babel - Error 1`] = `[SyntaxError: Missing semicolon. (1:4)]`;
diff --git a/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/_error_/non-identifier-name/snapshots/3-Alignment-Error.shot b/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/_error_/non-identifier-name/snapshots/3-Alignment-Error.shot
new file mode 100644
index 000000000000..7ccef6da61f4
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/_error_/non-identifier-name/snapshots/3-Alignment-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSTypeAliasDeclaration _error_ non-identifier-name Error Alignment 1`] = `"Both errored"`;
diff --git a/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/_error_/non-identifier-type-parameter/fixture.ts b/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/_error_/non-identifier-type-parameter/fixture.ts
new file mode 100644
index 000000000000..059c8eaf43d7
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/_error_/non-identifier-type-parameter/fixture.ts
@@ -0,0 +1 @@
+type T<1> = 2;
diff --git a/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/_error_/non-identifier-type-parameter/snapshots/1-TSESTree-Error.shot b/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/_error_/non-identifier-type-parameter/snapshots/1-TSESTree-Error.shot
new file mode 100644
index 000000000000..b11bc95c96d0
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/_error_/non-identifier-type-parameter/snapshots/1-TSESTree-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSTypeAliasDeclaration _error_ non-identifier-type-parameter TSESTree - Error 1`] = `[TSError: Type parameter declaration expected.]`;
diff --git a/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/_error_/non-identifier-type-parameter/snapshots/2-Babel-Error.shot b/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/_error_/non-identifier-type-parameter/snapshots/2-Babel-Error.shot
new file mode 100644
index 000000000000..bb7b44f3afec
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/_error_/non-identifier-type-parameter/snapshots/2-Babel-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSTypeAliasDeclaration _error_ non-identifier-type-parameter Babel - Error 1`] = `[SyntaxError: Unexpected token (1:7)]`;
diff --git a/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/_error_/non-identifier-type-parameter/snapshots/3-Alignment-Error.shot b/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/_error_/non-identifier-type-parameter/snapshots/3-Alignment-Error.shot
new file mode 100644
index 000000000000..ad412071cc11
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/_error_/non-identifier-type-parameter/snapshots/3-Alignment-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSTypeAliasDeclaration _error_ non-identifier-type-parameter Error Alignment 1`] = `"Both errored"`;
diff --git a/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/declare/fixture.ts b/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/declare/fixture.ts
new file mode 100644
index 000000000000..87882321e287
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/declare/fixture.ts
@@ -0,0 +1 @@
+declare type T = 1;
diff --git a/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/declare/snapshots/1-TSESTree-AST.shot b/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/declare/snapshots/1-TSESTree-AST.shot
new file mode 100644
index 000000000000..63becdaa218c
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/declare/snapshots/1-TSESTree-AST.shot
@@ -0,0 +1,56 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSTypeAliasDeclaration declare TSESTree - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    TSTypeAliasDeclaration {
+      type: "TSTypeAliasDeclaration",
+      declare: true,
+      id: Identifier {
+        type: "Identifier",
+        name: "T",
+
+        range: [13, 14],
+        loc: {
+          start: { column: 13, line: 1 },
+          end: { column: 14, line: 1 },
+        },
+      },
+      typeAnnotation: TSLiteralType {
+        type: "TSLiteralType",
+        literal: Literal {
+          type: "Literal",
+          raw: "1",
+          value: 1,
+
+          range: [17, 18],
+          loc: {
+            start: { column: 17, line: 1 },
+            end: { column: 18, line: 1 },
+          },
+        },
+
+        range: [17, 18],
+        loc: {
+          start: { column: 17, line: 1 },
+          end: { column: 18, line: 1 },
+        },
+      },
+
+      range: [0, 19],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 19, line: 1 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 20],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/declare/snapshots/2-TSESTree-Tokens.shot b/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/declare/snapshots/2-TSESTree-Tokens.shot
new file mode 100644
index 000000000000..8599ab306096
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/declare/snapshots/2-TSESTree-Tokens.shot
@@ -0,0 +1,66 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSTypeAliasDeclaration declare TSESTree - Tokens 1`] = `
+Array [
+  Identifier {
+    type: "Identifier",
+    value: "declare",
+
+    range: [0, 7],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 7, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "type",
+
+    range: [8, 12],
+    loc: {
+      start: { column: 8, line: 1 },
+      end: { column: 12, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "T",
+
+    range: [13, 14],
+    loc: {
+      start: { column: 13, line: 1 },
+      end: { column: 14, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "=",
+
+    range: [15, 16],
+    loc: {
+      start: { column: 15, line: 1 },
+      end: { column: 16, line: 1 },
+    },
+  },
+  Numeric {
+    type: "Numeric",
+    value: "1",
+
+    range: [17, 18],
+    loc: {
+      start: { column: 17, line: 1 },
+      end: { column: 18, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ";",
+
+    range: [18, 19],
+    loc: {
+      start: { column: 18, line: 1 },
+      end: { column: 19, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/declare/snapshots/3-Babel-AST.shot b/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/declare/snapshots/3-Babel-AST.shot
new file mode 100644
index 000000000000..36939724fc47
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/declare/snapshots/3-Babel-AST.shot
@@ -0,0 +1,56 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSTypeAliasDeclaration declare Babel - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    TSTypeAliasDeclaration {
+      type: "TSTypeAliasDeclaration",
+      declare: true,
+      id: Identifier {
+        type: "Identifier",
+        name: "T",
+
+        range: [13, 14],
+        loc: {
+          start: { column: 13, line: 1 },
+          end: { column: 14, line: 1 },
+        },
+      },
+      typeAnnotation: TSLiteralType {
+        type: "TSLiteralType",
+        literal: Literal {
+          type: "Literal",
+          raw: "1",
+          value: 1,
+
+          range: [17, 18],
+          loc: {
+            start: { column: 17, line: 1 },
+            end: { column: 18, line: 1 },
+          },
+        },
+
+        range: [17, 18],
+        loc: {
+          start: { column: 17, line: 1 },
+          end: { column: 18, line: 1 },
+        },
+      },
+
+      range: [0, 19],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 19, line: 1 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 20],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/declare/snapshots/4-Babel-Tokens.shot b/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/declare/snapshots/4-Babel-Tokens.shot
new file mode 100644
index 000000000000..48da9f1cfb8f
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/declare/snapshots/4-Babel-Tokens.shot
@@ -0,0 +1,66 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSTypeAliasDeclaration declare Babel - Tokens 1`] = `
+Array [
+  Identifier {
+    type: "Identifier",
+    value: "declare",
+
+    range: [0, 7],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 7, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "type",
+
+    range: [8, 12],
+    loc: {
+      start: { column: 8, line: 1 },
+      end: { column: 12, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "T",
+
+    range: [13, 14],
+    loc: {
+      start: { column: 13, line: 1 },
+      end: { column: 14, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "=",
+
+    range: [15, 16],
+    loc: {
+      start: { column: 15, line: 1 },
+      end: { column: 16, line: 1 },
+    },
+  },
+  Numeric {
+    type: "Numeric",
+    value: "1",
+
+    range: [17, 18],
+    loc: {
+      start: { column: 17, line: 1 },
+      end: { column: 18, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ";",
+
+    range: [18, 19],
+    loc: {
+      start: { column: 18, line: 1 },
+      end: { column: 19, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/declare/snapshots/5-AST-Alignment-AST.shot b/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/declare/snapshots/5-AST-Alignment-AST.shot
new file mode 100644
index 000000000000..890509a8dcbb
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/declare/snapshots/5-AST-Alignment-AST.shot
@@ -0,0 +1,6 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSTypeAliasDeclaration declare AST Alignment - AST 1`] = `
+"Snapshot Diff:
+Compared values have no visual difference."
+`;
diff --git a/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/declare/snapshots/6-AST-Alignment-Tokens.shot b/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/declare/snapshots/6-AST-Alignment-Tokens.shot
new file mode 100644
index 000000000000..6d9b60683b6e
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/declare/snapshots/6-AST-Alignment-Tokens.shot
@@ -0,0 +1,6 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSTypeAliasDeclaration declare AST Alignment - Token 1`] = `
+"Snapshot Diff:
+Compared values have no visual difference."
+`;
diff --git a/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/type-param-many/fixture.ts b/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/type-param-many/fixture.ts
new file mode 100644
index 000000000000..98fb2f852da4
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/type-param-many/fixture.ts
@@ -0,0 +1 @@
+type T<U> = 1;
diff --git a/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/type-param-many/snapshots/1-TSESTree-AST.shot b/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/type-param-many/snapshots/1-TSESTree-AST.shot
new file mode 100644
index 000000000000..af8a41ed4787
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/type-param-many/snapshots/1-TSESTree-AST.shot
@@ -0,0 +1,87 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSTypeAliasDeclaration type-param-many TSESTree - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    TSTypeAliasDeclaration {
+      type: "TSTypeAliasDeclaration",
+      id: Identifier {
+        type: "Identifier",
+        name: "T",
+
+        range: [5, 6],
+        loc: {
+          start: { column: 5, line: 1 },
+          end: { column: 6, line: 1 },
+        },
+      },
+      typeAnnotation: TSLiteralType {
+        type: "TSLiteralType",
+        literal: Literal {
+          type: "Literal",
+          raw: "1",
+          value: 1,
+
+          range: [12, 13],
+          loc: {
+            start: { column: 12, line: 1 },
+            end: { column: 13, line: 1 },
+          },
+        },
+
+        range: [12, 13],
+        loc: {
+          start: { column: 12, line: 1 },
+          end: { column: 13, line: 1 },
+        },
+      },
+      typeParameters: TSTypeParameterDeclaration {
+        type: "TSTypeParameterDeclaration",
+        params: Array [
+          TSTypeParameter {
+            type: "TSTypeParameter",
+            in: false,
+            name: Identifier {
+              type: "Identifier",
+              name: "U",
+
+              range: [7, 8],
+              loc: {
+                start: { column: 7, line: 1 },
+                end: { column: 8, line: 1 },
+              },
+            },
+            out: false,
+
+            range: [7, 8],
+            loc: {
+              start: { column: 7, line: 1 },
+              end: { column: 8, line: 1 },
+            },
+          },
+        ],
+
+        range: [6, 9],
+        loc: {
+          start: { column: 6, line: 1 },
+          end: { column: 9, line: 1 },
+        },
+      },
+
+      range: [0, 14],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 14, line: 1 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 15],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/type-param-many/snapshots/2-TSESTree-Tokens.shot b/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/type-param-many/snapshots/2-TSESTree-Tokens.shot
new file mode 100644
index 000000000000..a84e1cc058d2
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/type-param-many/snapshots/2-TSESTree-Tokens.shot
@@ -0,0 +1,86 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSTypeAliasDeclaration type-param-many TSESTree - Tokens 1`] = `
+Array [
+  Identifier {
+    type: "Identifier",
+    value: "type",
+
+    range: [0, 4],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 4, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "T",
+
+    range: [5, 6],
+    loc: {
+      start: { column: 5, line: 1 },
+      end: { column: 6, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "<",
+
+    range: [6, 7],
+    loc: {
+      start: { column: 6, line: 1 },
+      end: { column: 7, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "U",
+
+    range: [7, 8],
+    loc: {
+      start: { column: 7, line: 1 },
+      end: { column: 8, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ">",
+
+    range: [8, 9],
+    loc: {
+      start: { column: 8, line: 1 },
+      end: { column: 9, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "=",
+
+    range: [10, 11],
+    loc: {
+      start: { column: 10, line: 1 },
+      end: { column: 11, line: 1 },
+    },
+  },
+  Numeric {
+    type: "Numeric",
+    value: "1",
+
+    range: [12, 13],
+    loc: {
+      start: { column: 12, line: 1 },
+      end: { column: 13, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ";",
+
+    range: [13, 14],
+    loc: {
+      start: { column: 13, line: 1 },
+      end: { column: 14, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/type-param-many/snapshots/3-Babel-AST.shot b/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/type-param-many/snapshots/3-Babel-AST.shot
new file mode 100644
index 000000000000..db6209388e74
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/type-param-many/snapshots/3-Babel-AST.shot
@@ -0,0 +1,76 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSTypeAliasDeclaration type-param-many Babel - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    TSTypeAliasDeclaration {
+      type: "TSTypeAliasDeclaration",
+      id: Identifier {
+        type: "Identifier",
+        name: "T",
+
+        range: [5, 6],
+        loc: {
+          start: { column: 5, line: 1 },
+          end: { column: 6, line: 1 },
+        },
+      },
+      typeAnnotation: TSLiteralType {
+        type: "TSLiteralType",
+        literal: Literal {
+          type: "Literal",
+          raw: "1",
+          value: 1,
+
+          range: [12, 13],
+          loc: {
+            start: { column: 12, line: 1 },
+            end: { column: 13, line: 1 },
+          },
+        },
+
+        range: [12, 13],
+        loc: {
+          start: { column: 12, line: 1 },
+          end: { column: 13, line: 1 },
+        },
+      },
+      typeParameters: TSTypeParameterDeclaration {
+        type: "TSTypeParameterDeclaration",
+        params: Array [
+          TSTypeParameter {
+            type: "TSTypeParameter",
+            name: "U",
+
+            range: [7, 8],
+            loc: {
+              start: { column: 7, line: 1 },
+              end: { column: 8, line: 1 },
+            },
+          },
+        ],
+
+        range: [6, 9],
+        loc: {
+          start: { column: 6, line: 1 },
+          end: { column: 9, line: 1 },
+        },
+      },
+
+      range: [0, 14],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 14, line: 1 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 15],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/type-param-many/snapshots/4-Babel-Tokens.shot b/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/type-param-many/snapshots/4-Babel-Tokens.shot
new file mode 100644
index 000000000000..92442f10c0d8
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/type-param-many/snapshots/4-Babel-Tokens.shot
@@ -0,0 +1,86 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSTypeAliasDeclaration type-param-many Babel - Tokens 1`] = `
+Array [
+  Identifier {
+    type: "Identifier",
+    value: "type",
+
+    range: [0, 4],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 4, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "T",
+
+    range: [5, 6],
+    loc: {
+      start: { column: 5, line: 1 },
+      end: { column: 6, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "<",
+
+    range: [6, 7],
+    loc: {
+      start: { column: 6, line: 1 },
+      end: { column: 7, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "U",
+
+    range: [7, 8],
+    loc: {
+      start: { column: 7, line: 1 },
+      end: { column: 8, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ">",
+
+    range: [8, 9],
+    loc: {
+      start: { column: 8, line: 1 },
+      end: { column: 9, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "=",
+
+    range: [10, 11],
+    loc: {
+      start: { column: 10, line: 1 },
+      end: { column: 11, line: 1 },
+    },
+  },
+  Numeric {
+    type: "Numeric",
+    value: "1",
+
+    range: [12, 13],
+    loc: {
+      start: { column: 12, line: 1 },
+      end: { column: 13, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ";",
+
+    range: [13, 14],
+    loc: {
+      start: { column: 13, line: 1 },
+      end: { column: 14, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/type-param-many/snapshots/5-AST-Alignment-AST.shot b/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/type-param-many/snapshots/5-AST-Alignment-AST.shot
new file mode 100644
index 000000000000..a80b5aa0a110
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/type-param-many/snapshots/5-AST-Alignment-AST.shot
@@ -0,0 +1,92 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSTypeAliasDeclaration type-param-many AST Alignment - AST 1`] = `
+"Snapshot Diff:
+- TSESTree
++ Babel
+
+  Program {
+    type: 'Program',
+    body: Array [
+      TSTypeAliasDeclaration {
+        type: 'TSTypeAliasDeclaration',
+        id: Identifier {
+          type: 'Identifier',
+          name: 'T',
+
+          range: [5, 6],
+          loc: {
+            start: { column: 5, line: 1 },
+            end: { column: 6, line: 1 },
+          },
+        },
+        typeAnnotation: TSLiteralType {
+          type: 'TSLiteralType',
+          literal: Literal {
+            type: 'Literal',
+            raw: '1',
+            value: 1,
+
+            range: [12, 13],
+            loc: {
+              start: { column: 12, line: 1 },
+              end: { column: 13, line: 1 },
+            },
+          },
+
+          range: [12, 13],
+          loc: {
+            start: { column: 12, line: 1 },
+            end: { column: 13, line: 1 },
+          },
+        },
+        typeParameters: TSTypeParameterDeclaration {
+          type: 'TSTypeParameterDeclaration',
+          params: Array [
+            TSTypeParameter {
+              type: 'TSTypeParameter',
+-             in: false,
+-             name: Identifier {
+-               type: 'Identifier',
+-               name: 'U',
+-
+-               range: [7, 8],
+-               loc: {
+-                 start: { column: 7, line: 1 },
+-                 end: { column: 8, line: 1 },
+-               },
+-             },
+-             out: false,
++             name: 'U',
+
+              range: [7, 8],
+              loc: {
+                start: { column: 7, line: 1 },
+                end: { column: 8, line: 1 },
+              },
+            },
+          ],
+
+          range: [6, 9],
+          loc: {
+            start: { column: 6, line: 1 },
+            end: { column: 9, line: 1 },
+          },
+        },
+
+        range: [0, 14],
+        loc: {
+          start: { column: 0, line: 1 },
+          end: { column: 14, line: 1 },
+        },
+      },
+    ],
+    sourceType: 'script',
+
+    range: [0, 15],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 0, line: 2 },
+    },
+  }"
+`;
diff --git a/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/type-param-many/snapshots/6-AST-Alignment-Tokens.shot b/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/type-param-many/snapshots/6-AST-Alignment-Tokens.shot
new file mode 100644
index 000000000000..b693d3c055dd
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/type-param-many/snapshots/6-AST-Alignment-Tokens.shot
@@ -0,0 +1,6 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSTypeAliasDeclaration type-param-many AST Alignment - Token 1`] = `
+"Snapshot Diff:
+Compared values have no visual difference."
+`;
diff --git a/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/type-param-one/fixture.ts b/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/type-param-one/fixture.ts
new file mode 100644
index 000000000000..8ca0a9773130
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/type-param-one/fixture.ts
@@ -0,0 +1 @@
+type T<U, V, W> = 1;
diff --git a/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/type-param-one/snapshots/1-TSESTree-AST.shot b/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/type-param-one/snapshots/1-TSESTree-AST.shot
new file mode 100644
index 000000000000..6bf2120e61b4
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/type-param-one/snapshots/1-TSESTree-AST.shot
@@ -0,0 +1,129 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSTypeAliasDeclaration type-param-one TSESTree - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    TSTypeAliasDeclaration {
+      type: "TSTypeAliasDeclaration",
+      id: Identifier {
+        type: "Identifier",
+        name: "T",
+
+        range: [5, 6],
+        loc: {
+          start: { column: 5, line: 1 },
+          end: { column: 6, line: 1 },
+        },
+      },
+      typeAnnotation: TSLiteralType {
+        type: "TSLiteralType",
+        literal: Literal {
+          type: "Literal",
+          raw: "1",
+          value: 1,
+
+          range: [18, 19],
+          loc: {
+            start: { column: 18, line: 1 },
+            end: { column: 19, line: 1 },
+          },
+        },
+
+        range: [18, 19],
+        loc: {
+          start: { column: 18, line: 1 },
+          end: { column: 19, line: 1 },
+        },
+      },
+      typeParameters: TSTypeParameterDeclaration {
+        type: "TSTypeParameterDeclaration",
+        params: Array [
+          TSTypeParameter {
+            type: "TSTypeParameter",
+            in: false,
+            name: Identifier {
+              type: "Identifier",
+              name: "U",
+
+              range: [7, 8],
+              loc: {
+                start: { column: 7, line: 1 },
+                end: { column: 8, line: 1 },
+              },
+            },
+            out: false,
+
+            range: [7, 8],
+            loc: {
+              start: { column: 7, line: 1 },
+              end: { column: 8, line: 1 },
+            },
+          },
+          TSTypeParameter {
+            type: "TSTypeParameter",
+            in: false,
+            name: Identifier {
+              type: "Identifier",
+              name: "V",
+
+              range: [10, 11],
+              loc: {
+                start: { column: 10, line: 1 },
+                end: { column: 11, line: 1 },
+              },
+            },
+            out: false,
+
+            range: [10, 11],
+            loc: {
+              start: { column: 10, line: 1 },
+              end: { column: 11, line: 1 },
+            },
+          },
+          TSTypeParameter {
+            type: "TSTypeParameter",
+            in: false,
+            name: Identifier {
+              type: "Identifier",
+              name: "W",
+
+              range: [13, 14],
+              loc: {
+                start: { column: 13, line: 1 },
+                end: { column: 14, line: 1 },
+              },
+            },
+            out: false,
+
+            range: [13, 14],
+            loc: {
+              start: { column: 13, line: 1 },
+              end: { column: 14, line: 1 },
+            },
+          },
+        ],
+
+        range: [6, 15],
+        loc: {
+          start: { column: 6, line: 1 },
+          end: { column: 15, line: 1 },
+        },
+      },
+
+      range: [0, 20],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 20, line: 1 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 21],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/type-param-one/snapshots/2-TSESTree-Tokens.shot b/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/type-param-one/snapshots/2-TSESTree-Tokens.shot
new file mode 100644
index 000000000000..c23889fa8fd2
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/type-param-one/snapshots/2-TSESTree-Tokens.shot
@@ -0,0 +1,126 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSTypeAliasDeclaration type-param-one TSESTree - Tokens 1`] = `
+Array [
+  Identifier {
+    type: "Identifier",
+    value: "type",
+
+    range: [0, 4],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 4, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "T",
+
+    range: [5, 6],
+    loc: {
+      start: { column: 5, line: 1 },
+      end: { column: 6, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "<",
+
+    range: [6, 7],
+    loc: {
+      start: { column: 6, line: 1 },
+      end: { column: 7, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "U",
+
+    range: [7, 8],
+    loc: {
+      start: { column: 7, line: 1 },
+      end: { column: 8, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ",",
+
+    range: [8, 9],
+    loc: {
+      start: { column: 8, line: 1 },
+      end: { column: 9, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "V",
+
+    range: [10, 11],
+    loc: {
+      start: { column: 10, line: 1 },
+      end: { column: 11, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ",",
+
+    range: [11, 12],
+    loc: {
+      start: { column: 11, line: 1 },
+      end: { column: 12, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "W",
+
+    range: [13, 14],
+    loc: {
+      start: { column: 13, line: 1 },
+      end: { column: 14, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ">",
+
+    range: [14, 15],
+    loc: {
+      start: { column: 14, line: 1 },
+      end: { column: 15, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "=",
+
+    range: [16, 17],
+    loc: {
+      start: { column: 16, line: 1 },
+      end: { column: 17, line: 1 },
+    },
+  },
+  Numeric {
+    type: "Numeric",
+    value: "1",
+
+    range: [18, 19],
+    loc: {
+      start: { column: 18, line: 1 },
+      end: { column: 19, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ";",
+
+    range: [19, 20],
+    loc: {
+      start: { column: 19, line: 1 },
+      end: { column: 20, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/type-param-one/snapshots/3-Babel-AST.shot b/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/type-param-one/snapshots/3-Babel-AST.shot
new file mode 100644
index 000000000000..60c8977e60f3
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/type-param-one/snapshots/3-Babel-AST.shot
@@ -0,0 +1,96 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSTypeAliasDeclaration type-param-one Babel - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    TSTypeAliasDeclaration {
+      type: "TSTypeAliasDeclaration",
+      id: Identifier {
+        type: "Identifier",
+        name: "T",
+
+        range: [5, 6],
+        loc: {
+          start: { column: 5, line: 1 },
+          end: { column: 6, line: 1 },
+        },
+      },
+      typeAnnotation: TSLiteralType {
+        type: "TSLiteralType",
+        literal: Literal {
+          type: "Literal",
+          raw: "1",
+          value: 1,
+
+          range: [18, 19],
+          loc: {
+            start: { column: 18, line: 1 },
+            end: { column: 19, line: 1 },
+          },
+        },
+
+        range: [18, 19],
+        loc: {
+          start: { column: 18, line: 1 },
+          end: { column: 19, line: 1 },
+        },
+      },
+      typeParameters: TSTypeParameterDeclaration {
+        type: "TSTypeParameterDeclaration",
+        params: Array [
+          TSTypeParameter {
+            type: "TSTypeParameter",
+            name: "U",
+
+            range: [7, 8],
+            loc: {
+              start: { column: 7, line: 1 },
+              end: { column: 8, line: 1 },
+            },
+          },
+          TSTypeParameter {
+            type: "TSTypeParameter",
+            name: "V",
+
+            range: [10, 11],
+            loc: {
+              start: { column: 10, line: 1 },
+              end: { column: 11, line: 1 },
+            },
+          },
+          TSTypeParameter {
+            type: "TSTypeParameter",
+            name: "W",
+
+            range: [13, 14],
+            loc: {
+              start: { column: 13, line: 1 },
+              end: { column: 14, line: 1 },
+            },
+          },
+        ],
+
+        range: [6, 15],
+        loc: {
+          start: { column: 6, line: 1 },
+          end: { column: 15, line: 1 },
+        },
+      },
+
+      range: [0, 20],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 20, line: 1 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 21],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/type-param-one/snapshots/4-Babel-Tokens.shot b/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/type-param-one/snapshots/4-Babel-Tokens.shot
new file mode 100644
index 000000000000..f6e56c2aa5fb
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/type-param-one/snapshots/4-Babel-Tokens.shot
@@ -0,0 +1,126 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSTypeAliasDeclaration type-param-one Babel - Tokens 1`] = `
+Array [
+  Identifier {
+    type: "Identifier",
+    value: "type",
+
+    range: [0, 4],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 4, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "T",
+
+    range: [5, 6],
+    loc: {
+      start: { column: 5, line: 1 },
+      end: { column: 6, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "<",
+
+    range: [6, 7],
+    loc: {
+      start: { column: 6, line: 1 },
+      end: { column: 7, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "U",
+
+    range: [7, 8],
+    loc: {
+      start: { column: 7, line: 1 },
+      end: { column: 8, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ",",
+
+    range: [8, 9],
+    loc: {
+      start: { column: 8, line: 1 },
+      end: { column: 9, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "V",
+
+    range: [10, 11],
+    loc: {
+      start: { column: 10, line: 1 },
+      end: { column: 11, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ",",
+
+    range: [11, 12],
+    loc: {
+      start: { column: 11, line: 1 },
+      end: { column: 12, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "W",
+
+    range: [13, 14],
+    loc: {
+      start: { column: 13, line: 1 },
+      end: { column: 14, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ">",
+
+    range: [14, 15],
+    loc: {
+      start: { column: 14, line: 1 },
+      end: { column: 15, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "=",
+
+    range: [16, 17],
+    loc: {
+      start: { column: 16, line: 1 },
+      end: { column: 17, line: 1 },
+    },
+  },
+  Numeric {
+    type: "Numeric",
+    value: "1",
+
+    range: [18, 19],
+    loc: {
+      start: { column: 18, line: 1 },
+      end: { column: 19, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ";",
+
+    range: [19, 20],
+    loc: {
+      start: { column: 19, line: 1 },
+      end: { column: 20, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/type-param-one/snapshots/5-AST-Alignment-AST.shot b/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/type-param-one/snapshots/5-AST-Alignment-AST.shot
new file mode 100644
index 000000000000..d754f2bf397b
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/type-param-one/snapshots/5-AST-Alignment-AST.shot
@@ -0,0 +1,136 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSTypeAliasDeclaration type-param-one AST Alignment - AST 1`] = `
+"Snapshot Diff:
+- TSESTree
++ Babel
+
+  Program {
+    type: 'Program',
+    body: Array [
+      TSTypeAliasDeclaration {
+        type: 'TSTypeAliasDeclaration',
+        id: Identifier {
+          type: 'Identifier',
+          name: 'T',
+
+          range: [5, 6],
+          loc: {
+            start: { column: 5, line: 1 },
+            end: { column: 6, line: 1 },
+          },
+        },
+        typeAnnotation: TSLiteralType {
+          type: 'TSLiteralType',
+          literal: Literal {
+            type: 'Literal',
+            raw: '1',
+            value: 1,
+
+            range: [18, 19],
+            loc: {
+              start: { column: 18, line: 1 },
+              end: { column: 19, line: 1 },
+            },
+          },
+
+          range: [18, 19],
+          loc: {
+            start: { column: 18, line: 1 },
+            end: { column: 19, line: 1 },
+          },
+        },
+        typeParameters: TSTypeParameterDeclaration {
+          type: 'TSTypeParameterDeclaration',
+          params: Array [
+            TSTypeParameter {
+              type: 'TSTypeParameter',
+-             in: false,
+-             name: Identifier {
+-               type: 'Identifier',
+-               name: 'U',
+-
+-               range: [7, 8],
+-               loc: {
+-                 start: { column: 7, line: 1 },
+-                 end: { column: 8, line: 1 },
+-               },
+-             },
+-             out: false,
++             name: 'U',
+
+              range: [7, 8],
+              loc: {
+                start: { column: 7, line: 1 },
+                end: { column: 8, line: 1 },
+              },
+            },
+            TSTypeParameter {
+              type: 'TSTypeParameter',
+-             in: false,
+-             name: Identifier {
+-               type: 'Identifier',
+-               name: 'V',
+-
+-               range: [10, 11],
+-               loc: {
+-                 start: { column: 10, line: 1 },
+-                 end: { column: 11, line: 1 },
+-               },
+-             },
+-             out: false,
++             name: 'V',
+
+              range: [10, 11],
+              loc: {
+                start: { column: 10, line: 1 },
+                end: { column: 11, line: 1 },
+              },
+            },
+            TSTypeParameter {
+              type: 'TSTypeParameter',
+-             in: false,
+-             name: Identifier {
+-               type: 'Identifier',
+-               name: 'W',
+-
+-               range: [13, 14],
+-               loc: {
+-                 start: { column: 13, line: 1 },
+-                 end: { column: 14, line: 1 },
+-               },
+-             },
+-             out: false,
++             name: 'W',
+
+              range: [13, 14],
+              loc: {
+                start: { column: 13, line: 1 },
+                end: { column: 14, line: 1 },
+              },
+            },
+          ],
+
+          range: [6, 15],
+          loc: {
+            start: { column: 6, line: 1 },
+            end: { column: 15, line: 1 },
+          },
+        },
+
+        range: [0, 20],
+        loc: {
+          start: { column: 0, line: 1 },
+          end: { column: 20, line: 1 },
+        },
+      },
+    ],
+    sourceType: 'script',
+
+    range: [0, 21],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 0, line: 2 },
+    },
+  }"
+`;
diff --git a/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/type-param-one/snapshots/6-AST-Alignment-Tokens.shot b/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/type-param-one/snapshots/6-AST-Alignment-Tokens.shot
new file mode 100644
index 000000000000..bc7fa2d6aac4
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/type-param-one/snapshots/6-AST-Alignment-Tokens.shot
@@ -0,0 +1,6 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSTypeAliasDeclaration type-param-one AST Alignment - Token 1`] = `
+"Snapshot Diff:
+Compared values have no visual difference."
+`;
diff --git a/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/valid/fixture.ts b/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/valid/fixture.ts
new file mode 100644
index 000000000000..0d6d62642cc2
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/valid/fixture.ts
@@ -0,0 +1 @@
+type T = 1;
diff --git a/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/valid/snapshots/1-TSESTree-AST.shot b/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/valid/snapshots/1-TSESTree-AST.shot
new file mode 100644
index 000000000000..424ed29eb522
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/valid/snapshots/1-TSESTree-AST.shot
@@ -0,0 +1,55 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSTypeAliasDeclaration valid TSESTree - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    TSTypeAliasDeclaration {
+      type: "TSTypeAliasDeclaration",
+      id: Identifier {
+        type: "Identifier",
+        name: "T",
+
+        range: [5, 6],
+        loc: {
+          start: { column: 5, line: 1 },
+          end: { column: 6, line: 1 },
+        },
+      },
+      typeAnnotation: TSLiteralType {
+        type: "TSLiteralType",
+        literal: Literal {
+          type: "Literal",
+          raw: "1",
+          value: 1,
+
+          range: [9, 10],
+          loc: {
+            start: { column: 9, line: 1 },
+            end: { column: 10, line: 1 },
+          },
+        },
+
+        range: [9, 10],
+        loc: {
+          start: { column: 9, line: 1 },
+          end: { column: 10, line: 1 },
+        },
+      },
+
+      range: [0, 11],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 11, line: 1 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 12],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/valid/snapshots/2-TSESTree-Tokens.shot b/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/valid/snapshots/2-TSESTree-Tokens.shot
new file mode 100644
index 000000000000..e3b35e444aa7
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/valid/snapshots/2-TSESTree-Tokens.shot
@@ -0,0 +1,56 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSTypeAliasDeclaration valid TSESTree - Tokens 1`] = `
+Array [
+  Identifier {
+    type: "Identifier",
+    value: "type",
+
+    range: [0, 4],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 4, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "T",
+
+    range: [5, 6],
+    loc: {
+      start: { column: 5, line: 1 },
+      end: { column: 6, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "=",
+
+    range: [7, 8],
+    loc: {
+      start: { column: 7, line: 1 },
+      end: { column: 8, line: 1 },
+    },
+  },
+  Numeric {
+    type: "Numeric",
+    value: "1",
+
+    range: [9, 10],
+    loc: {
+      start: { column: 9, line: 1 },
+      end: { column: 10, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ";",
+
+    range: [10, 11],
+    loc: {
+      start: { column: 10, line: 1 },
+      end: { column: 11, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/valid/snapshots/3-Babel-AST.shot b/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/valid/snapshots/3-Babel-AST.shot
new file mode 100644
index 000000000000..7fad93c1cab8
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/valid/snapshots/3-Babel-AST.shot
@@ -0,0 +1,55 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSTypeAliasDeclaration valid Babel - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    TSTypeAliasDeclaration {
+      type: "TSTypeAliasDeclaration",
+      id: Identifier {
+        type: "Identifier",
+        name: "T",
+
+        range: [5, 6],
+        loc: {
+          start: { column: 5, line: 1 },
+          end: { column: 6, line: 1 },
+        },
+      },
+      typeAnnotation: TSLiteralType {
+        type: "TSLiteralType",
+        literal: Literal {
+          type: "Literal",
+          raw: "1",
+          value: 1,
+
+          range: [9, 10],
+          loc: {
+            start: { column: 9, line: 1 },
+            end: { column: 10, line: 1 },
+          },
+        },
+
+        range: [9, 10],
+        loc: {
+          start: { column: 9, line: 1 },
+          end: { column: 10, line: 1 },
+        },
+      },
+
+      range: [0, 11],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 11, line: 1 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 12],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/valid/snapshots/4-Babel-Tokens.shot b/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/valid/snapshots/4-Babel-Tokens.shot
new file mode 100644
index 000000000000..12901c93f94c
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/valid/snapshots/4-Babel-Tokens.shot
@@ -0,0 +1,56 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSTypeAliasDeclaration valid Babel - Tokens 1`] = `
+Array [
+  Identifier {
+    type: "Identifier",
+    value: "type",
+
+    range: [0, 4],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 4, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "T",
+
+    range: [5, 6],
+    loc: {
+      start: { column: 5, line: 1 },
+      end: { column: 6, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "=",
+
+    range: [7, 8],
+    loc: {
+      start: { column: 7, line: 1 },
+      end: { column: 8, line: 1 },
+    },
+  },
+  Numeric {
+    type: "Numeric",
+    value: "1",
+
+    range: [9, 10],
+    loc: {
+      start: { column: 9, line: 1 },
+      end: { column: 10, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ";",
+
+    range: [10, 11],
+    loc: {
+      start: { column: 10, line: 1 },
+      end: { column: 11, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/valid/snapshots/5-AST-Alignment-AST.shot b/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/valid/snapshots/5-AST-Alignment-AST.shot
new file mode 100644
index 000000000000..9cc16a451ec1
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/valid/snapshots/5-AST-Alignment-AST.shot
@@ -0,0 +1,6 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSTypeAliasDeclaration valid AST Alignment - AST 1`] = `
+"Snapshot Diff:
+Compared values have no visual difference."
+`;
diff --git a/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/valid/snapshots/6-AST-Alignment-Tokens.shot b/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/valid/snapshots/6-AST-Alignment-Tokens.shot
new file mode 100644
index 000000000000..4de04778d631
--- /dev/null
+++ b/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/fixtures/valid/snapshots/6-AST-Alignment-Tokens.shot
@@ -0,0 +1,6 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration TSTypeAliasDeclaration valid AST Alignment - Token 1`] = `
+"Snapshot Diff:
+Compared values have no visual difference."
+`;
diff --git a/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/spec.ts b/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/spec.ts
index 61ce986c2a23..15ab0a40c131 100644
--- a/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/spec.ts
+++ b/packages/ast-spec/src/declaration/TSTypeAliasDeclaration/spec.ts
@@ -6,8 +6,25 @@ import type { TypeNode } from '../../unions/TypeNode';
 
 export interface TSTypeAliasDeclaration extends BaseNode {
   type: AST_NODE_TYPES.TSTypeAliasDeclaration;
+  /**
+   * Whether the type was `declare`d.
+   * ```
+   * declare type T = 1;
+   * ```
+   */
+  // TODO(#5020) - make this `false` if it is not `declare`d
+  declare?: boolean;
+  /**
+   * The name of the type.
+   */
   id: Identifier;
+  /**
+   * The "value" (type) of the declaration
+   */
   typeAnnotation: TypeNode;
-  declare?: boolean;
+  /**
+   * The generic type parameters declared for the type.
+   * This is `undefined` if there are no generic type parameters declared.
+   */
   typeParameters?: TSTypeParameterDeclaration;
 }
diff --git a/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/_error_/missing-id-with-value/fixture.ts b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/_error_/missing-id-with-value/fixture.ts
new file mode 100644
index 000000000000..21a6e1beba95
--- /dev/null
+++ b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/_error_/missing-id-with-value/fixture.ts
@@ -0,0 +1 @@
+const = 1;
diff --git a/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/_error_/missing-id-with-value/snapshots/1-TSESTree-Error.shot b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/_error_/missing-id-with-value/snapshots/1-TSESTree-Error.shot
new file mode 100644
index 000000000000..3f61a7ec4bde
--- /dev/null
+++ b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/_error_/missing-id-with-value/snapshots/1-TSESTree-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration VariableDeclaration _error_ missing-id-with-value TSESTree - Error 1`] = `[TSError: Variable declaration expected.]`;
diff --git a/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/_error_/missing-id-with-value/snapshots/2-Babel-Error.shot b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/_error_/missing-id-with-value/snapshots/2-Babel-Error.shot
new file mode 100644
index 000000000000..5e6f7bc3288b
--- /dev/null
+++ b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/_error_/missing-id-with-value/snapshots/2-Babel-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration VariableDeclaration _error_ missing-id-with-value Babel - Error 1`] = `[SyntaxError: Unexpected token (1:6)]`;
diff --git a/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/_error_/missing-id-with-value/snapshots/3-Alignment-Error.shot b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/_error_/missing-id-with-value/snapshots/3-Alignment-Error.shot
new file mode 100644
index 000000000000..830f2f4e93c8
--- /dev/null
+++ b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/_error_/missing-id-with-value/snapshots/3-Alignment-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration VariableDeclaration _error_ missing-id-with-value Error Alignment 1`] = `"Both errored"`;
diff --git a/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/_error_/missing-id-without-value/fixture.ts b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/_error_/missing-id-without-value/fixture.ts
new file mode 100644
index 000000000000..c53e6c279527
--- /dev/null
+++ b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/_error_/missing-id-without-value/fixture.ts
@@ -0,0 +1 @@
+const;
diff --git a/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/_error_/missing-id-without-value/snapshots/1-TSESTree-Error.shot b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/_error_/missing-id-without-value/snapshots/1-TSESTree-Error.shot
new file mode 100644
index 000000000000..6537d529262e
--- /dev/null
+++ b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/_error_/missing-id-without-value/snapshots/1-TSESTree-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration VariableDeclaration _error_ missing-id-without-value TSESTree - Error 1`] = `"NO ERROR"`;
diff --git a/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/_error_/missing-id-without-value/snapshots/2-Babel-Error.shot b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/_error_/missing-id-without-value/snapshots/2-Babel-Error.shot
new file mode 100644
index 000000000000..7a42d0e079b6
--- /dev/null
+++ b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/_error_/missing-id-without-value/snapshots/2-Babel-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration VariableDeclaration _error_ missing-id-without-value Babel - Error 1`] = `[SyntaxError: Unexpected token (1:5)]`;
diff --git a/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/_error_/missing-id-without-value/snapshots/3-Alignment-Error.shot b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/_error_/missing-id-without-value/snapshots/3-Alignment-Error.shot
new file mode 100644
index 000000000000..cd2401b6862d
--- /dev/null
+++ b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/_error_/missing-id-without-value/snapshots/3-Alignment-Error.shot
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration VariableDeclaration _error_ missing-id-without-value Error Alignment 1`] = `"Babel errored but TSESTree didn't"`;
diff --git a/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/const-with-value/fixture.ts b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/const-with-value/fixture.ts
new file mode 100644
index 000000000000..943c458c79e2
--- /dev/null
+++ b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/const-with-value/fixture.ts
@@ -0,0 +1 @@
+const x = 1;
diff --git a/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/const-with-value/snapshots/1-TSESTree-AST.shot b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/const-with-value/snapshots/1-TSESTree-AST.shot
new file mode 100644
index 000000000000..d7290bd926df
--- /dev/null
+++ b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/const-with-value/snapshots/1-TSESTree-AST.shot
@@ -0,0 +1,58 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration VariableDeclaration const-with-value TSESTree - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    VariableDeclaration {
+      type: "VariableDeclaration",
+      declarations: Array [
+        VariableDeclarator {
+          type: "VariableDeclarator",
+          id: Identifier {
+            type: "Identifier",
+            name: "x",
+
+            range: [6, 7],
+            loc: {
+              start: { column: 6, line: 1 },
+              end: { column: 7, line: 1 },
+            },
+          },
+          init: Literal {
+            type: "Literal",
+            raw: "1",
+            value: 1,
+
+            range: [10, 11],
+            loc: {
+              start: { column: 10, line: 1 },
+              end: { column: 11, line: 1 },
+            },
+          },
+
+          range: [6, 11],
+          loc: {
+            start: { column: 6, line: 1 },
+            end: { column: 11, line: 1 },
+          },
+        },
+      ],
+      kind: "const",
+
+      range: [0, 12],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 12, line: 1 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 13],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/const-with-value/snapshots/2-TSESTree-Tokens.shot b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/const-with-value/snapshots/2-TSESTree-Tokens.shot
new file mode 100644
index 000000000000..df6fc4d39980
--- /dev/null
+++ b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/const-with-value/snapshots/2-TSESTree-Tokens.shot
@@ -0,0 +1,56 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration VariableDeclaration const-with-value TSESTree - Tokens 1`] = `
+Array [
+  Keyword {
+    type: "Keyword",
+    value: "const",
+
+    range: [0, 5],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 5, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "x",
+
+    range: [6, 7],
+    loc: {
+      start: { column: 6, line: 1 },
+      end: { column: 7, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "=",
+
+    range: [8, 9],
+    loc: {
+      start: { column: 8, line: 1 },
+      end: { column: 9, line: 1 },
+    },
+  },
+  Numeric {
+    type: "Numeric",
+    value: "1",
+
+    range: [10, 11],
+    loc: {
+      start: { column: 10, line: 1 },
+      end: { column: 11, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ";",
+
+    range: [11, 12],
+    loc: {
+      start: { column: 11, line: 1 },
+      end: { column: 12, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/const-with-value/snapshots/3-Babel-AST.shot b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/const-with-value/snapshots/3-Babel-AST.shot
new file mode 100644
index 000000000000..2cd36dbb4678
--- /dev/null
+++ b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/const-with-value/snapshots/3-Babel-AST.shot
@@ -0,0 +1,58 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration VariableDeclaration const-with-value Babel - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    VariableDeclaration {
+      type: "VariableDeclaration",
+      declarations: Array [
+        VariableDeclarator {
+          type: "VariableDeclarator",
+          id: Identifier {
+            type: "Identifier",
+            name: "x",
+
+            range: [6, 7],
+            loc: {
+              start: { column: 6, line: 1 },
+              end: { column: 7, line: 1 },
+            },
+          },
+          init: Literal {
+            type: "Literal",
+            raw: "1",
+            value: 1,
+
+            range: [10, 11],
+            loc: {
+              start: { column: 10, line: 1 },
+              end: { column: 11, line: 1 },
+            },
+          },
+
+          range: [6, 11],
+          loc: {
+            start: { column: 6, line: 1 },
+            end: { column: 11, line: 1 },
+          },
+        },
+      ],
+      kind: "const",
+
+      range: [0, 12],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 12, line: 1 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 13],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/const-with-value/snapshots/4-Babel-Tokens.shot b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/const-with-value/snapshots/4-Babel-Tokens.shot
new file mode 100644
index 000000000000..5a5ce6855a2f
--- /dev/null
+++ b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/const-with-value/snapshots/4-Babel-Tokens.shot
@@ -0,0 +1,56 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration VariableDeclaration const-with-value Babel - Tokens 1`] = `
+Array [
+  Keyword {
+    type: "Keyword",
+    value: "const",
+
+    range: [0, 5],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 5, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "x",
+
+    range: [6, 7],
+    loc: {
+      start: { column: 6, line: 1 },
+      end: { column: 7, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "=",
+
+    range: [8, 9],
+    loc: {
+      start: { column: 8, line: 1 },
+      end: { column: 9, line: 1 },
+    },
+  },
+  Numeric {
+    type: "Numeric",
+    value: "1",
+
+    range: [10, 11],
+    loc: {
+      start: { column: 10, line: 1 },
+      end: { column: 11, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ";",
+
+    range: [11, 12],
+    loc: {
+      start: { column: 11, line: 1 },
+      end: { column: 12, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/const-with-value/snapshots/5-AST-Alignment-AST.shot b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/const-with-value/snapshots/5-AST-Alignment-AST.shot
new file mode 100644
index 000000000000..65c9ece0d433
--- /dev/null
+++ b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/const-with-value/snapshots/5-AST-Alignment-AST.shot
@@ -0,0 +1,6 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration VariableDeclaration const-with-value AST Alignment - AST 1`] = `
+"Snapshot Diff:
+Compared values have no visual difference."
+`;
diff --git a/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/const-with-value/snapshots/6-AST-Alignment-Tokens.shot b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/const-with-value/snapshots/6-AST-Alignment-Tokens.shot
new file mode 100644
index 000000000000..abc02d7344bf
--- /dev/null
+++ b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/const-with-value/snapshots/6-AST-Alignment-Tokens.shot
@@ -0,0 +1,6 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration VariableDeclaration const-with-value AST Alignment - Token 1`] = `
+"Snapshot Diff:
+Compared values have no visual difference."
+`;
diff --git a/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/const-without-value/fixture.ts b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/const-without-value/fixture.ts
new file mode 100644
index 000000000000..943c458c79e2
--- /dev/null
+++ b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/const-without-value/fixture.ts
@@ -0,0 +1 @@
+const x = 1;
diff --git a/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/const-without-value/snapshots/1-TSESTree-AST.shot b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/const-without-value/snapshots/1-TSESTree-AST.shot
new file mode 100644
index 000000000000..ac4cd6b70d89
--- /dev/null
+++ b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/const-without-value/snapshots/1-TSESTree-AST.shot
@@ -0,0 +1,58 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration VariableDeclaration const-without-value TSESTree - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    VariableDeclaration {
+      type: "VariableDeclaration",
+      declarations: Array [
+        VariableDeclarator {
+          type: "VariableDeclarator",
+          id: Identifier {
+            type: "Identifier",
+            name: "x",
+
+            range: [6, 7],
+            loc: {
+              start: { column: 6, line: 1 },
+              end: { column: 7, line: 1 },
+            },
+          },
+          init: Literal {
+            type: "Literal",
+            raw: "1",
+            value: 1,
+
+            range: [10, 11],
+            loc: {
+              start: { column: 10, line: 1 },
+              end: { column: 11, line: 1 },
+            },
+          },
+
+          range: [6, 11],
+          loc: {
+            start: { column: 6, line: 1 },
+            end: { column: 11, line: 1 },
+          },
+        },
+      ],
+      kind: "const",
+
+      range: [0, 12],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 12, line: 1 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 13],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/const-without-value/snapshots/2-TSESTree-Tokens.shot b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/const-without-value/snapshots/2-TSESTree-Tokens.shot
new file mode 100644
index 000000000000..ee275ed63d97
--- /dev/null
+++ b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/const-without-value/snapshots/2-TSESTree-Tokens.shot
@@ -0,0 +1,56 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration VariableDeclaration const-without-value TSESTree - Tokens 1`] = `
+Array [
+  Keyword {
+    type: "Keyword",
+    value: "const",
+
+    range: [0, 5],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 5, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "x",
+
+    range: [6, 7],
+    loc: {
+      start: { column: 6, line: 1 },
+      end: { column: 7, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "=",
+
+    range: [8, 9],
+    loc: {
+      start: { column: 8, line: 1 },
+      end: { column: 9, line: 1 },
+    },
+  },
+  Numeric {
+    type: "Numeric",
+    value: "1",
+
+    range: [10, 11],
+    loc: {
+      start: { column: 10, line: 1 },
+      end: { column: 11, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ";",
+
+    range: [11, 12],
+    loc: {
+      start: { column: 11, line: 1 },
+      end: { column: 12, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/const-without-value/snapshots/3-Babel-AST.shot b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/const-without-value/snapshots/3-Babel-AST.shot
new file mode 100644
index 000000000000..c41b8219393c
--- /dev/null
+++ b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/const-without-value/snapshots/3-Babel-AST.shot
@@ -0,0 +1,58 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration VariableDeclaration const-without-value Babel - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    VariableDeclaration {
+      type: "VariableDeclaration",
+      declarations: Array [
+        VariableDeclarator {
+          type: "VariableDeclarator",
+          id: Identifier {
+            type: "Identifier",
+            name: "x",
+
+            range: [6, 7],
+            loc: {
+              start: { column: 6, line: 1 },
+              end: { column: 7, line: 1 },
+            },
+          },
+          init: Literal {
+            type: "Literal",
+            raw: "1",
+            value: 1,
+
+            range: [10, 11],
+            loc: {
+              start: { column: 10, line: 1 },
+              end: { column: 11, line: 1 },
+            },
+          },
+
+          range: [6, 11],
+          loc: {
+            start: { column: 6, line: 1 },
+            end: { column: 11, line: 1 },
+          },
+        },
+      ],
+      kind: "const",
+
+      range: [0, 12],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 12, line: 1 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 13],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/const-without-value/snapshots/4-Babel-Tokens.shot b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/const-without-value/snapshots/4-Babel-Tokens.shot
new file mode 100644
index 000000000000..62b0896e9fd9
--- /dev/null
+++ b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/const-without-value/snapshots/4-Babel-Tokens.shot
@@ -0,0 +1,56 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration VariableDeclaration const-without-value Babel - Tokens 1`] = `
+Array [
+  Keyword {
+    type: "Keyword",
+    value: "const",
+
+    range: [0, 5],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 5, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "x",
+
+    range: [6, 7],
+    loc: {
+      start: { column: 6, line: 1 },
+      end: { column: 7, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "=",
+
+    range: [8, 9],
+    loc: {
+      start: { column: 8, line: 1 },
+      end: { column: 9, line: 1 },
+    },
+  },
+  Numeric {
+    type: "Numeric",
+    value: "1",
+
+    range: [10, 11],
+    loc: {
+      start: { column: 10, line: 1 },
+      end: { column: 11, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ";",
+
+    range: [11, 12],
+    loc: {
+      start: { column: 11, line: 1 },
+      end: { column: 12, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/const-without-value/snapshots/5-AST-Alignment-AST.shot b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/const-without-value/snapshots/5-AST-Alignment-AST.shot
new file mode 100644
index 000000000000..56007597c389
--- /dev/null
+++ b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/const-without-value/snapshots/5-AST-Alignment-AST.shot
@@ -0,0 +1,6 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration VariableDeclaration const-without-value AST Alignment - AST 1`] = `
+"Snapshot Diff:
+Compared values have no visual difference."
+`;
diff --git a/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/const-without-value/snapshots/6-AST-Alignment-Tokens.shot b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/const-without-value/snapshots/6-AST-Alignment-Tokens.shot
new file mode 100644
index 000000000000..cc37accf3c50
--- /dev/null
+++ b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/const-without-value/snapshots/6-AST-Alignment-Tokens.shot
@@ -0,0 +1,6 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration VariableDeclaration const-without-value AST Alignment - Token 1`] = `
+"Snapshot Diff:
+Compared values have no visual difference."
+`;
diff --git a/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/declare/fixture.ts b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/declare/fixture.ts
new file mode 100644
index 000000000000..3dc63502e9ca
--- /dev/null
+++ b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/declare/fixture.ts
@@ -0,0 +1 @@
+declare let x;
diff --git a/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/declare/snapshots/1-TSESTree-AST.shot b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/declare/snapshots/1-TSESTree-AST.shot
new file mode 100644
index 000000000000..19c59fcc338c
--- /dev/null
+++ b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/declare/snapshots/1-TSESTree-AST.shot
@@ -0,0 +1,49 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration VariableDeclaration declare TSESTree - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    VariableDeclaration {
+      type: "VariableDeclaration",
+      declarations: Array [
+        VariableDeclarator {
+          type: "VariableDeclarator",
+          id: Identifier {
+            type: "Identifier",
+            name: "x",
+
+            range: [12, 13],
+            loc: {
+              start: { column: 12, line: 1 },
+              end: { column: 13, line: 1 },
+            },
+          },
+          init: null,
+
+          range: [12, 13],
+          loc: {
+            start: { column: 12, line: 1 },
+            end: { column: 13, line: 1 },
+          },
+        },
+      ],
+      declare: true,
+      kind: "let",
+
+      range: [0, 14],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 14, line: 1 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 15],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/declare/snapshots/2-TSESTree-Tokens.shot b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/declare/snapshots/2-TSESTree-Tokens.shot
new file mode 100644
index 000000000000..5e3638b00d8f
--- /dev/null
+++ b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/declare/snapshots/2-TSESTree-Tokens.shot
@@ -0,0 +1,46 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration VariableDeclaration declare TSESTree - Tokens 1`] = `
+Array [
+  Identifier {
+    type: "Identifier",
+    value: "declare",
+
+    range: [0, 7],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 7, line: 1 },
+    },
+  },
+  Keyword {
+    type: "Keyword",
+    value: "let",
+
+    range: [8, 11],
+    loc: {
+      start: { column: 8, line: 1 },
+      end: { column: 11, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "x",
+
+    range: [12, 13],
+    loc: {
+      start: { column: 12, line: 1 },
+      end: { column: 13, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ";",
+
+    range: [13, 14],
+    loc: {
+      start: { column: 13, line: 1 },
+      end: { column: 14, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/declare/snapshots/3-Babel-AST.shot b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/declare/snapshots/3-Babel-AST.shot
new file mode 100644
index 000000000000..9cd49f740e41
--- /dev/null
+++ b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/declare/snapshots/3-Babel-AST.shot
@@ -0,0 +1,49 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration VariableDeclaration declare Babel - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    VariableDeclaration {
+      type: "VariableDeclaration",
+      declarations: Array [
+        VariableDeclarator {
+          type: "VariableDeclarator",
+          id: Identifier {
+            type: "Identifier",
+            name: "x",
+
+            range: [12, 13],
+            loc: {
+              start: { column: 12, line: 1 },
+              end: { column: 13, line: 1 },
+            },
+          },
+          init: null,
+
+          range: [12, 13],
+          loc: {
+            start: { column: 12, line: 1 },
+            end: { column: 13, line: 1 },
+          },
+        },
+      ],
+      declare: true,
+      kind: "let",
+
+      range: [0, 14],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 14, line: 1 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 15],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/declare/snapshots/4-Babel-Tokens.shot b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/declare/snapshots/4-Babel-Tokens.shot
new file mode 100644
index 000000000000..5b7e380551c3
--- /dev/null
+++ b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/declare/snapshots/4-Babel-Tokens.shot
@@ -0,0 +1,46 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration VariableDeclaration declare Babel - Tokens 1`] = `
+Array [
+  Identifier {
+    type: "Identifier",
+    value: "declare",
+
+    range: [0, 7],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 7, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "let",
+
+    range: [8, 11],
+    loc: {
+      start: { column: 8, line: 1 },
+      end: { column: 11, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "x",
+
+    range: [12, 13],
+    loc: {
+      start: { column: 12, line: 1 },
+      end: { column: 13, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ";",
+
+    range: [13, 14],
+    loc: {
+      start: { column: 13, line: 1 },
+      end: { column: 14, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/declare/snapshots/5-AST-Alignment-AST.shot b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/declare/snapshots/5-AST-Alignment-AST.shot
new file mode 100644
index 000000000000..005dc078e1de
--- /dev/null
+++ b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/declare/snapshots/5-AST-Alignment-AST.shot
@@ -0,0 +1,6 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration VariableDeclaration declare AST Alignment - AST 1`] = `
+"Snapshot Diff:
+Compared values have no visual difference."
+`;
diff --git a/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/declare/snapshots/6-AST-Alignment-Tokens.shot b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/declare/snapshots/6-AST-Alignment-Tokens.shot
new file mode 100644
index 000000000000..6d4eee5276a1
--- /dev/null
+++ b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/declare/snapshots/6-AST-Alignment-Tokens.shot
@@ -0,0 +1,52 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration VariableDeclaration declare AST Alignment - Token 1`] = `
+"Snapshot Diff:
+- TSESTree
++ Babel
+
+  Array [
+    Identifier {
+      type: 'Identifier',
+      value: 'declare',
+
+      range: [0, 7],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 7, line: 1 },
+      },
+    },
+-   Keyword {
+-     type: 'Keyword',
++   Identifier {
++     type: 'Identifier',
+      value: 'let',
+
+      range: [8, 11],
+      loc: {
+        start: { column: 8, line: 1 },
+        end: { column: 11, line: 1 },
+      },
+    },
+    Identifier {
+      type: 'Identifier',
+      value: 'x',
+
+      range: [12, 13],
+      loc: {
+        start: { column: 12, line: 1 },
+        end: { column: 13, line: 1 },
+      },
+    },
+    Punctuator {
+      type: 'Punctuator',
+      value: ';',
+
+      range: [13, 14],
+      loc: {
+        start: { column: 13, line: 1 },
+        end: { column: 14, line: 1 },
+      },
+    },
+  ]"
+`;
diff --git a/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/let-with-value/fixture.ts b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/let-with-value/fixture.ts
new file mode 100644
index 000000000000..db9133994486
--- /dev/null
+++ b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/let-with-value/fixture.ts
@@ -0,0 +1 @@
+let x = 1;
diff --git a/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/let-with-value/snapshots/1-TSESTree-AST.shot b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/let-with-value/snapshots/1-TSESTree-AST.shot
new file mode 100644
index 000000000000..a1c7625b4576
--- /dev/null
+++ b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/let-with-value/snapshots/1-TSESTree-AST.shot
@@ -0,0 +1,58 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration VariableDeclaration let-with-value TSESTree - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    VariableDeclaration {
+      type: "VariableDeclaration",
+      declarations: Array [
+        VariableDeclarator {
+          type: "VariableDeclarator",
+          id: Identifier {
+            type: "Identifier",
+            name: "x",
+
+            range: [4, 5],
+            loc: {
+              start: { column: 4, line: 1 },
+              end: { column: 5, line: 1 },
+            },
+          },
+          init: Literal {
+            type: "Literal",
+            raw: "1",
+            value: 1,
+
+            range: [8, 9],
+            loc: {
+              start: { column: 8, line: 1 },
+              end: { column: 9, line: 1 },
+            },
+          },
+
+          range: [4, 9],
+          loc: {
+            start: { column: 4, line: 1 },
+            end: { column: 9, line: 1 },
+          },
+        },
+      ],
+      kind: "let",
+
+      range: [0, 10],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 10, line: 1 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 11],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/let-with-value/snapshots/2-TSESTree-Tokens.shot b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/let-with-value/snapshots/2-TSESTree-Tokens.shot
new file mode 100644
index 000000000000..fa835fcdd32a
--- /dev/null
+++ b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/let-with-value/snapshots/2-TSESTree-Tokens.shot
@@ -0,0 +1,56 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration VariableDeclaration let-with-value TSESTree - Tokens 1`] = `
+Array [
+  Keyword {
+    type: "Keyword",
+    value: "let",
+
+    range: [0, 3],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 3, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "x",
+
+    range: [4, 5],
+    loc: {
+      start: { column: 4, line: 1 },
+      end: { column: 5, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "=",
+
+    range: [6, 7],
+    loc: {
+      start: { column: 6, line: 1 },
+      end: { column: 7, line: 1 },
+    },
+  },
+  Numeric {
+    type: "Numeric",
+    value: "1",
+
+    range: [8, 9],
+    loc: {
+      start: { column: 8, line: 1 },
+      end: { column: 9, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ";",
+
+    range: [9, 10],
+    loc: {
+      start: { column: 9, line: 1 },
+      end: { column: 10, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/let-with-value/snapshots/3-Babel-AST.shot b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/let-with-value/snapshots/3-Babel-AST.shot
new file mode 100644
index 000000000000..5c5236d0482c
--- /dev/null
+++ b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/let-with-value/snapshots/3-Babel-AST.shot
@@ -0,0 +1,58 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration VariableDeclaration let-with-value Babel - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    VariableDeclaration {
+      type: "VariableDeclaration",
+      declarations: Array [
+        VariableDeclarator {
+          type: "VariableDeclarator",
+          id: Identifier {
+            type: "Identifier",
+            name: "x",
+
+            range: [4, 5],
+            loc: {
+              start: { column: 4, line: 1 },
+              end: { column: 5, line: 1 },
+            },
+          },
+          init: Literal {
+            type: "Literal",
+            raw: "1",
+            value: 1,
+
+            range: [8, 9],
+            loc: {
+              start: { column: 8, line: 1 },
+              end: { column: 9, line: 1 },
+            },
+          },
+
+          range: [4, 9],
+          loc: {
+            start: { column: 4, line: 1 },
+            end: { column: 9, line: 1 },
+          },
+        },
+      ],
+      kind: "let",
+
+      range: [0, 10],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 10, line: 1 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 11],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/let-with-value/snapshots/4-Babel-Tokens.shot b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/let-with-value/snapshots/4-Babel-Tokens.shot
new file mode 100644
index 000000000000..6f4bc74a6bd3
--- /dev/null
+++ b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/let-with-value/snapshots/4-Babel-Tokens.shot
@@ -0,0 +1,56 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration VariableDeclaration let-with-value Babel - Tokens 1`] = `
+Array [
+  Identifier {
+    type: "Identifier",
+    value: "let",
+
+    range: [0, 3],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 3, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "x",
+
+    range: [4, 5],
+    loc: {
+      start: { column: 4, line: 1 },
+      end: { column: 5, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "=",
+
+    range: [6, 7],
+    loc: {
+      start: { column: 6, line: 1 },
+      end: { column: 7, line: 1 },
+    },
+  },
+  Numeric {
+    type: "Numeric",
+    value: "1",
+
+    range: [8, 9],
+    loc: {
+      start: { column: 8, line: 1 },
+      end: { column: 9, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ";",
+
+    range: [9, 10],
+    loc: {
+      start: { column: 9, line: 1 },
+      end: { column: 10, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/let-with-value/snapshots/5-AST-Alignment-AST.shot b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/let-with-value/snapshots/5-AST-Alignment-AST.shot
new file mode 100644
index 000000000000..2697799a4159
--- /dev/null
+++ b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/let-with-value/snapshots/5-AST-Alignment-AST.shot
@@ -0,0 +1,6 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration VariableDeclaration let-with-value AST Alignment - AST 1`] = `
+"Snapshot Diff:
+Compared values have no visual difference."
+`;
diff --git a/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/let-with-value/snapshots/6-AST-Alignment-Tokens.shot b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/let-with-value/snapshots/6-AST-Alignment-Tokens.shot
new file mode 100644
index 000000000000..e8e2c1727b2f
--- /dev/null
+++ b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/let-with-value/snapshots/6-AST-Alignment-Tokens.shot
@@ -0,0 +1,62 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration VariableDeclaration let-with-value AST Alignment - Token 1`] = `
+"Snapshot Diff:
+- TSESTree
++ Babel
+
+  Array [
+-   Keyword {
+-     type: 'Keyword',
++   Identifier {
++     type: 'Identifier',
+      value: 'let',
+
+      range: [0, 3],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 3, line: 1 },
+      },
+    },
+    Identifier {
+      type: 'Identifier',
+      value: 'x',
+
+      range: [4, 5],
+      loc: {
+        start: { column: 4, line: 1 },
+        end: { column: 5, line: 1 },
+      },
+    },
+    Punctuator {
+      type: 'Punctuator',
+      value: '=',
+
+      range: [6, 7],
+      loc: {
+        start: { column: 6, line: 1 },
+        end: { column: 7, line: 1 },
+      },
+    },
+    Numeric {
+      type: 'Numeric',
+      value: '1',
+
+      range: [8, 9],
+      loc: {
+        start: { column: 8, line: 1 },
+        end: { column: 9, line: 1 },
+      },
+    },
+    Punctuator {
+      type: 'Punctuator',
+      value: ';',
+
+      range: [9, 10],
+      loc: {
+        start: { column: 9, line: 1 },
+        end: { column: 10, line: 1 },
+      },
+    },
+  ]"
+`;
diff --git a/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/let-without-value/fixture.ts b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/let-without-value/fixture.ts
new file mode 100644
index 000000000000..2756c24c4577
--- /dev/null
+++ b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/let-without-value/fixture.ts
@@ -0,0 +1 @@
+let x;
diff --git a/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/let-without-value/snapshots/1-TSESTree-AST.shot b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/let-without-value/snapshots/1-TSESTree-AST.shot
new file mode 100644
index 000000000000..86d5e5fb9d11
--- /dev/null
+++ b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/let-without-value/snapshots/1-TSESTree-AST.shot
@@ -0,0 +1,48 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration VariableDeclaration let-without-value TSESTree - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    VariableDeclaration {
+      type: "VariableDeclaration",
+      declarations: Array [
+        VariableDeclarator {
+          type: "VariableDeclarator",
+          id: Identifier {
+            type: "Identifier",
+            name: "x",
+
+            range: [4, 5],
+            loc: {
+              start: { column: 4, line: 1 },
+              end: { column: 5, line: 1 },
+            },
+          },
+          init: null,
+
+          range: [4, 5],
+          loc: {
+            start: { column: 4, line: 1 },
+            end: { column: 5, line: 1 },
+          },
+        },
+      ],
+      kind: "let",
+
+      range: [0, 6],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 6, line: 1 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 7],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/let-without-value/snapshots/2-TSESTree-Tokens.shot b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/let-without-value/snapshots/2-TSESTree-Tokens.shot
new file mode 100644
index 000000000000..66e4c76e5674
--- /dev/null
+++ b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/let-without-value/snapshots/2-TSESTree-Tokens.shot
@@ -0,0 +1,36 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration VariableDeclaration let-without-value TSESTree - Tokens 1`] = `
+Array [
+  Keyword {
+    type: "Keyword",
+    value: "let",
+
+    range: [0, 3],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 3, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "x",
+
+    range: [4, 5],
+    loc: {
+      start: { column: 4, line: 1 },
+      end: { column: 5, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ";",
+
+    range: [5, 6],
+    loc: {
+      start: { column: 5, line: 1 },
+      end: { column: 6, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/let-without-value/snapshots/3-Babel-AST.shot b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/let-without-value/snapshots/3-Babel-AST.shot
new file mode 100644
index 000000000000..78ac80c4cf49
--- /dev/null
+++ b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/let-without-value/snapshots/3-Babel-AST.shot
@@ -0,0 +1,48 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration VariableDeclaration let-without-value Babel - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    VariableDeclaration {
+      type: "VariableDeclaration",
+      declarations: Array [
+        VariableDeclarator {
+          type: "VariableDeclarator",
+          id: Identifier {
+            type: "Identifier",
+            name: "x",
+
+            range: [4, 5],
+            loc: {
+              start: { column: 4, line: 1 },
+              end: { column: 5, line: 1 },
+            },
+          },
+          init: null,
+
+          range: [4, 5],
+          loc: {
+            start: { column: 4, line: 1 },
+            end: { column: 5, line: 1 },
+          },
+        },
+      ],
+      kind: "let",
+
+      range: [0, 6],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 6, line: 1 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 7],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/let-without-value/snapshots/4-Babel-Tokens.shot b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/let-without-value/snapshots/4-Babel-Tokens.shot
new file mode 100644
index 000000000000..78f58826ca69
--- /dev/null
+++ b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/let-without-value/snapshots/4-Babel-Tokens.shot
@@ -0,0 +1,36 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration VariableDeclaration let-without-value Babel - Tokens 1`] = `
+Array [
+  Identifier {
+    type: "Identifier",
+    value: "let",
+
+    range: [0, 3],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 3, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "x",
+
+    range: [4, 5],
+    loc: {
+      start: { column: 4, line: 1 },
+      end: { column: 5, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ";",
+
+    range: [5, 6],
+    loc: {
+      start: { column: 5, line: 1 },
+      end: { column: 6, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/let-without-value/snapshots/5-AST-Alignment-AST.shot b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/let-without-value/snapshots/5-AST-Alignment-AST.shot
new file mode 100644
index 000000000000..8082a31f808a
--- /dev/null
+++ b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/let-without-value/snapshots/5-AST-Alignment-AST.shot
@@ -0,0 +1,6 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration VariableDeclaration let-without-value AST Alignment - AST 1`] = `
+"Snapshot Diff:
+Compared values have no visual difference."
+`;
diff --git a/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/let-without-value/snapshots/6-AST-Alignment-Tokens.shot b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/let-without-value/snapshots/6-AST-Alignment-Tokens.shot
new file mode 100644
index 000000000000..949c66669c79
--- /dev/null
+++ b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/let-without-value/snapshots/6-AST-Alignment-Tokens.shot
@@ -0,0 +1,42 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration VariableDeclaration let-without-value AST Alignment - Token 1`] = `
+"Snapshot Diff:
+- TSESTree
++ Babel
+
+  Array [
+-   Keyword {
+-     type: 'Keyword',
++   Identifier {
++     type: 'Identifier',
+      value: 'let',
+
+      range: [0, 3],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 3, line: 1 },
+      },
+    },
+    Identifier {
+      type: 'Identifier',
+      value: 'x',
+
+      range: [4, 5],
+      loc: {
+        start: { column: 4, line: 1 },
+        end: { column: 5, line: 1 },
+      },
+    },
+    Punctuator {
+      type: 'Punctuator',
+      value: ';',
+
+      range: [5, 6],
+      loc: {
+        start: { column: 5, line: 1 },
+        end: { column: 6, line: 1 },
+      },
+    },
+  ]"
+`;
diff --git a/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/multiple-declarations/fixture.ts b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/multiple-declarations/fixture.ts
new file mode 100644
index 000000000000..6736426d70f2
--- /dev/null
+++ b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/multiple-declarations/fixture.ts
@@ -0,0 +1 @@
+let x, y, z;
diff --git a/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/multiple-declarations/snapshots/1-TSESTree-AST.shot b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/multiple-declarations/snapshots/1-TSESTree-AST.shot
new file mode 100644
index 000000000000..f34767c5d507
--- /dev/null
+++ b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/multiple-declarations/snapshots/1-TSESTree-AST.shot
@@ -0,0 +1,88 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration VariableDeclaration multiple-declarations TSESTree - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    VariableDeclaration {
+      type: "VariableDeclaration",
+      declarations: Array [
+        VariableDeclarator {
+          type: "VariableDeclarator",
+          id: Identifier {
+            type: "Identifier",
+            name: "x",
+
+            range: [4, 5],
+            loc: {
+              start: { column: 4, line: 1 },
+              end: { column: 5, line: 1 },
+            },
+          },
+          init: null,
+
+          range: [4, 5],
+          loc: {
+            start: { column: 4, line: 1 },
+            end: { column: 5, line: 1 },
+          },
+        },
+        VariableDeclarator {
+          type: "VariableDeclarator",
+          id: Identifier {
+            type: "Identifier",
+            name: "y",
+
+            range: [7, 8],
+            loc: {
+              start: { column: 7, line: 1 },
+              end: { column: 8, line: 1 },
+            },
+          },
+          init: null,
+
+          range: [7, 8],
+          loc: {
+            start: { column: 7, line: 1 },
+            end: { column: 8, line: 1 },
+          },
+        },
+        VariableDeclarator {
+          type: "VariableDeclarator",
+          id: Identifier {
+            type: "Identifier",
+            name: "z",
+
+            range: [10, 11],
+            loc: {
+              start: { column: 10, line: 1 },
+              end: { column: 11, line: 1 },
+            },
+          },
+          init: null,
+
+          range: [10, 11],
+          loc: {
+            start: { column: 10, line: 1 },
+            end: { column: 11, line: 1 },
+          },
+        },
+      ],
+      kind: "let",
+
+      range: [0, 12],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 12, line: 1 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 13],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/multiple-declarations/snapshots/2-TSESTree-Tokens.shot b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/multiple-declarations/snapshots/2-TSESTree-Tokens.shot
new file mode 100644
index 000000000000..b47b272ca688
--- /dev/null
+++ b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/multiple-declarations/snapshots/2-TSESTree-Tokens.shot
@@ -0,0 +1,76 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration VariableDeclaration multiple-declarations TSESTree - Tokens 1`] = `
+Array [
+  Keyword {
+    type: "Keyword",
+    value: "let",
+
+    range: [0, 3],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 3, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "x",
+
+    range: [4, 5],
+    loc: {
+      start: { column: 4, line: 1 },
+      end: { column: 5, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ",",
+
+    range: [5, 6],
+    loc: {
+      start: { column: 5, line: 1 },
+      end: { column: 6, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "y",
+
+    range: [7, 8],
+    loc: {
+      start: { column: 7, line: 1 },
+      end: { column: 8, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ",",
+
+    range: [8, 9],
+    loc: {
+      start: { column: 8, line: 1 },
+      end: { column: 9, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "z",
+
+    range: [10, 11],
+    loc: {
+      start: { column: 10, line: 1 },
+      end: { column: 11, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ";",
+
+    range: [11, 12],
+    loc: {
+      start: { column: 11, line: 1 },
+      end: { column: 12, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/multiple-declarations/snapshots/3-Babel-AST.shot b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/multiple-declarations/snapshots/3-Babel-AST.shot
new file mode 100644
index 000000000000..b52ef7582475
--- /dev/null
+++ b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/multiple-declarations/snapshots/3-Babel-AST.shot
@@ -0,0 +1,88 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration VariableDeclaration multiple-declarations Babel - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    VariableDeclaration {
+      type: "VariableDeclaration",
+      declarations: Array [
+        VariableDeclarator {
+          type: "VariableDeclarator",
+          id: Identifier {
+            type: "Identifier",
+            name: "x",
+
+            range: [4, 5],
+            loc: {
+              start: { column: 4, line: 1 },
+              end: { column: 5, line: 1 },
+            },
+          },
+          init: null,
+
+          range: [4, 5],
+          loc: {
+            start: { column: 4, line: 1 },
+            end: { column: 5, line: 1 },
+          },
+        },
+        VariableDeclarator {
+          type: "VariableDeclarator",
+          id: Identifier {
+            type: "Identifier",
+            name: "y",
+
+            range: [7, 8],
+            loc: {
+              start: { column: 7, line: 1 },
+              end: { column: 8, line: 1 },
+            },
+          },
+          init: null,
+
+          range: [7, 8],
+          loc: {
+            start: { column: 7, line: 1 },
+            end: { column: 8, line: 1 },
+          },
+        },
+        VariableDeclarator {
+          type: "VariableDeclarator",
+          id: Identifier {
+            type: "Identifier",
+            name: "z",
+
+            range: [10, 11],
+            loc: {
+              start: { column: 10, line: 1 },
+              end: { column: 11, line: 1 },
+            },
+          },
+          init: null,
+
+          range: [10, 11],
+          loc: {
+            start: { column: 10, line: 1 },
+            end: { column: 11, line: 1 },
+          },
+        },
+      ],
+      kind: "let",
+
+      range: [0, 12],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 12, line: 1 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 13],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/multiple-declarations/snapshots/4-Babel-Tokens.shot b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/multiple-declarations/snapshots/4-Babel-Tokens.shot
new file mode 100644
index 000000000000..2e324512abe7
--- /dev/null
+++ b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/multiple-declarations/snapshots/4-Babel-Tokens.shot
@@ -0,0 +1,76 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration VariableDeclaration multiple-declarations Babel - Tokens 1`] = `
+Array [
+  Identifier {
+    type: "Identifier",
+    value: "let",
+
+    range: [0, 3],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 3, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "x",
+
+    range: [4, 5],
+    loc: {
+      start: { column: 4, line: 1 },
+      end: { column: 5, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ",",
+
+    range: [5, 6],
+    loc: {
+      start: { column: 5, line: 1 },
+      end: { column: 6, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "y",
+
+    range: [7, 8],
+    loc: {
+      start: { column: 7, line: 1 },
+      end: { column: 8, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ",",
+
+    range: [8, 9],
+    loc: {
+      start: { column: 8, line: 1 },
+      end: { column: 9, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "z",
+
+    range: [10, 11],
+    loc: {
+      start: { column: 10, line: 1 },
+      end: { column: 11, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ";",
+
+    range: [11, 12],
+    loc: {
+      start: { column: 11, line: 1 },
+      end: { column: 12, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/multiple-declarations/snapshots/5-AST-Alignment-AST.shot b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/multiple-declarations/snapshots/5-AST-Alignment-AST.shot
new file mode 100644
index 000000000000..10b9167907cb
--- /dev/null
+++ b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/multiple-declarations/snapshots/5-AST-Alignment-AST.shot
@@ -0,0 +1,6 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration VariableDeclaration multiple-declarations AST Alignment - AST 1`] = `
+"Snapshot Diff:
+Compared values have no visual difference."
+`;
diff --git a/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/multiple-declarations/snapshots/6-AST-Alignment-Tokens.shot b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/multiple-declarations/snapshots/6-AST-Alignment-Tokens.shot
new file mode 100644
index 000000000000..d1e4b8c9a7b5
--- /dev/null
+++ b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/multiple-declarations/snapshots/6-AST-Alignment-Tokens.shot
@@ -0,0 +1,82 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration VariableDeclaration multiple-declarations AST Alignment - Token 1`] = `
+"Snapshot Diff:
+- TSESTree
++ Babel
+
+  Array [
+-   Keyword {
+-     type: 'Keyword',
++   Identifier {
++     type: 'Identifier',
+      value: 'let',
+
+      range: [0, 3],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 3, line: 1 },
+      },
+    },
+    Identifier {
+      type: 'Identifier',
+      value: 'x',
+
+      range: [4, 5],
+      loc: {
+        start: { column: 4, line: 1 },
+        end: { column: 5, line: 1 },
+      },
+    },
+    Punctuator {
+      type: 'Punctuator',
+      value: ',',
+
+      range: [5, 6],
+      loc: {
+        start: { column: 5, line: 1 },
+        end: { column: 6, line: 1 },
+      },
+    },
+    Identifier {
+      type: 'Identifier',
+      value: 'y',
+
+      range: [7, 8],
+      loc: {
+        start: { column: 7, line: 1 },
+        end: { column: 8, line: 1 },
+      },
+    },
+    Punctuator {
+      type: 'Punctuator',
+      value: ',',
+
+      range: [8, 9],
+      loc: {
+        start: { column: 8, line: 1 },
+        end: { column: 9, line: 1 },
+      },
+    },
+    Identifier {
+      type: 'Identifier',
+      value: 'z',
+
+      range: [10, 11],
+      loc: {
+        start: { column: 10, line: 1 },
+        end: { column: 11, line: 1 },
+      },
+    },
+    Punctuator {
+      type: 'Punctuator',
+      value: ';',
+
+      range: [11, 12],
+      loc: {
+        start: { column: 11, line: 1 },
+        end: { column: 12, line: 1 },
+      },
+    },
+  ]"
+`;
diff --git a/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/var-with-value/fixture.ts b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/var-with-value/fixture.ts
new file mode 100644
index 000000000000..b506100a909f
--- /dev/null
+++ b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/var-with-value/fixture.ts
@@ -0,0 +1 @@
+var x = 1;
diff --git a/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/var-with-value/snapshots/1-TSESTree-AST.shot b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/var-with-value/snapshots/1-TSESTree-AST.shot
new file mode 100644
index 000000000000..d0b455dc1a23
--- /dev/null
+++ b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/var-with-value/snapshots/1-TSESTree-AST.shot
@@ -0,0 +1,58 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration VariableDeclaration var-with-value TSESTree - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    VariableDeclaration {
+      type: "VariableDeclaration",
+      declarations: Array [
+        VariableDeclarator {
+          type: "VariableDeclarator",
+          id: Identifier {
+            type: "Identifier",
+            name: "x",
+
+            range: [4, 5],
+            loc: {
+              start: { column: 4, line: 1 },
+              end: { column: 5, line: 1 },
+            },
+          },
+          init: Literal {
+            type: "Literal",
+            raw: "1",
+            value: 1,
+
+            range: [8, 9],
+            loc: {
+              start: { column: 8, line: 1 },
+              end: { column: 9, line: 1 },
+            },
+          },
+
+          range: [4, 9],
+          loc: {
+            start: { column: 4, line: 1 },
+            end: { column: 9, line: 1 },
+          },
+        },
+      ],
+      kind: "var",
+
+      range: [0, 10],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 10, line: 1 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 11],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/var-with-value/snapshots/2-TSESTree-Tokens.shot b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/var-with-value/snapshots/2-TSESTree-Tokens.shot
new file mode 100644
index 000000000000..2f9b9d787042
--- /dev/null
+++ b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/var-with-value/snapshots/2-TSESTree-Tokens.shot
@@ -0,0 +1,56 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration VariableDeclaration var-with-value TSESTree - Tokens 1`] = `
+Array [
+  Keyword {
+    type: "Keyword",
+    value: "var",
+
+    range: [0, 3],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 3, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "x",
+
+    range: [4, 5],
+    loc: {
+      start: { column: 4, line: 1 },
+      end: { column: 5, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "=",
+
+    range: [6, 7],
+    loc: {
+      start: { column: 6, line: 1 },
+      end: { column: 7, line: 1 },
+    },
+  },
+  Numeric {
+    type: "Numeric",
+    value: "1",
+
+    range: [8, 9],
+    loc: {
+      start: { column: 8, line: 1 },
+      end: { column: 9, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ";",
+
+    range: [9, 10],
+    loc: {
+      start: { column: 9, line: 1 },
+      end: { column: 10, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/var-with-value/snapshots/3-Babel-AST.shot b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/var-with-value/snapshots/3-Babel-AST.shot
new file mode 100644
index 000000000000..1420d42a8ca0
--- /dev/null
+++ b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/var-with-value/snapshots/3-Babel-AST.shot
@@ -0,0 +1,58 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration VariableDeclaration var-with-value Babel - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    VariableDeclaration {
+      type: "VariableDeclaration",
+      declarations: Array [
+        VariableDeclarator {
+          type: "VariableDeclarator",
+          id: Identifier {
+            type: "Identifier",
+            name: "x",
+
+            range: [4, 5],
+            loc: {
+              start: { column: 4, line: 1 },
+              end: { column: 5, line: 1 },
+            },
+          },
+          init: Literal {
+            type: "Literal",
+            raw: "1",
+            value: 1,
+
+            range: [8, 9],
+            loc: {
+              start: { column: 8, line: 1 },
+              end: { column: 9, line: 1 },
+            },
+          },
+
+          range: [4, 9],
+          loc: {
+            start: { column: 4, line: 1 },
+            end: { column: 9, line: 1 },
+          },
+        },
+      ],
+      kind: "var",
+
+      range: [0, 10],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 10, line: 1 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 11],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/var-with-value/snapshots/4-Babel-Tokens.shot b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/var-with-value/snapshots/4-Babel-Tokens.shot
new file mode 100644
index 000000000000..bbab28532c67
--- /dev/null
+++ b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/var-with-value/snapshots/4-Babel-Tokens.shot
@@ -0,0 +1,56 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration VariableDeclaration var-with-value Babel - Tokens 1`] = `
+Array [
+  Keyword {
+    type: "Keyword",
+    value: "var",
+
+    range: [0, 3],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 3, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "x",
+
+    range: [4, 5],
+    loc: {
+      start: { column: 4, line: 1 },
+      end: { column: 5, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: "=",
+
+    range: [6, 7],
+    loc: {
+      start: { column: 6, line: 1 },
+      end: { column: 7, line: 1 },
+    },
+  },
+  Numeric {
+    type: "Numeric",
+    value: "1",
+
+    range: [8, 9],
+    loc: {
+      start: { column: 8, line: 1 },
+      end: { column: 9, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ";",
+
+    range: [9, 10],
+    loc: {
+      start: { column: 9, line: 1 },
+      end: { column: 10, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/var-with-value/snapshots/5-AST-Alignment-AST.shot b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/var-with-value/snapshots/5-AST-Alignment-AST.shot
new file mode 100644
index 000000000000..b107c9499d49
--- /dev/null
+++ b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/var-with-value/snapshots/5-AST-Alignment-AST.shot
@@ -0,0 +1,6 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration VariableDeclaration var-with-value AST Alignment - AST 1`] = `
+"Snapshot Diff:
+Compared values have no visual difference."
+`;
diff --git a/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/var-with-value/snapshots/6-AST-Alignment-Tokens.shot b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/var-with-value/snapshots/6-AST-Alignment-Tokens.shot
new file mode 100644
index 000000000000..1eb3bcd0b986
--- /dev/null
+++ b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/var-with-value/snapshots/6-AST-Alignment-Tokens.shot
@@ -0,0 +1,6 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration VariableDeclaration var-with-value AST Alignment - Token 1`] = `
+"Snapshot Diff:
+Compared values have no visual difference."
+`;
diff --git a/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/var-without-value/fixture.ts b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/var-without-value/fixture.ts
new file mode 100644
index 000000000000..96f6d3a3f15b
--- /dev/null
+++ b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/var-without-value/fixture.ts
@@ -0,0 +1 @@
+var x;
diff --git a/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/var-without-value/snapshots/1-TSESTree-AST.shot b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/var-without-value/snapshots/1-TSESTree-AST.shot
new file mode 100644
index 000000000000..9af840c2c538
--- /dev/null
+++ b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/var-without-value/snapshots/1-TSESTree-AST.shot
@@ -0,0 +1,48 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration VariableDeclaration var-without-value TSESTree - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    VariableDeclaration {
+      type: "VariableDeclaration",
+      declarations: Array [
+        VariableDeclarator {
+          type: "VariableDeclarator",
+          id: Identifier {
+            type: "Identifier",
+            name: "x",
+
+            range: [4, 5],
+            loc: {
+              start: { column: 4, line: 1 },
+              end: { column: 5, line: 1 },
+            },
+          },
+          init: null,
+
+          range: [4, 5],
+          loc: {
+            start: { column: 4, line: 1 },
+            end: { column: 5, line: 1 },
+          },
+        },
+      ],
+      kind: "var",
+
+      range: [0, 6],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 6, line: 1 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 7],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/var-without-value/snapshots/2-TSESTree-Tokens.shot b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/var-without-value/snapshots/2-TSESTree-Tokens.shot
new file mode 100644
index 000000000000..ba7245b545ed
--- /dev/null
+++ b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/var-without-value/snapshots/2-TSESTree-Tokens.shot
@@ -0,0 +1,36 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration VariableDeclaration var-without-value TSESTree - Tokens 1`] = `
+Array [
+  Keyword {
+    type: "Keyword",
+    value: "var",
+
+    range: [0, 3],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 3, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "x",
+
+    range: [4, 5],
+    loc: {
+      start: { column: 4, line: 1 },
+      end: { column: 5, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ";",
+
+    range: [5, 6],
+    loc: {
+      start: { column: 5, line: 1 },
+      end: { column: 6, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/var-without-value/snapshots/3-Babel-AST.shot b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/var-without-value/snapshots/3-Babel-AST.shot
new file mode 100644
index 000000000000..a3bb2551bf26
--- /dev/null
+++ b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/var-without-value/snapshots/3-Babel-AST.shot
@@ -0,0 +1,48 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration VariableDeclaration var-without-value Babel - AST 1`] = `
+Program {
+  type: "Program",
+  body: Array [
+    VariableDeclaration {
+      type: "VariableDeclaration",
+      declarations: Array [
+        VariableDeclarator {
+          type: "VariableDeclarator",
+          id: Identifier {
+            type: "Identifier",
+            name: "x",
+
+            range: [4, 5],
+            loc: {
+              start: { column: 4, line: 1 },
+              end: { column: 5, line: 1 },
+            },
+          },
+          init: null,
+
+          range: [4, 5],
+          loc: {
+            start: { column: 4, line: 1 },
+            end: { column: 5, line: 1 },
+          },
+        },
+      ],
+      kind: "var",
+
+      range: [0, 6],
+      loc: {
+        start: { column: 0, line: 1 },
+        end: { column: 6, line: 1 },
+      },
+    },
+  ],
+  sourceType: "script",
+
+  range: [0, 7],
+  loc: {
+    start: { column: 0, line: 1 },
+    end: { column: 0, line: 2 },
+  },
+}
+`;
diff --git a/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/var-without-value/snapshots/4-Babel-Tokens.shot b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/var-without-value/snapshots/4-Babel-Tokens.shot
new file mode 100644
index 000000000000..289daee1ace2
--- /dev/null
+++ b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/var-without-value/snapshots/4-Babel-Tokens.shot
@@ -0,0 +1,36 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration VariableDeclaration var-without-value Babel - Tokens 1`] = `
+Array [
+  Keyword {
+    type: "Keyword",
+    value: "var",
+
+    range: [0, 3],
+    loc: {
+      start: { column: 0, line: 1 },
+      end: { column: 3, line: 1 },
+    },
+  },
+  Identifier {
+    type: "Identifier",
+    value: "x",
+
+    range: [4, 5],
+    loc: {
+      start: { column: 4, line: 1 },
+      end: { column: 5, line: 1 },
+    },
+  },
+  Punctuator {
+    type: "Punctuator",
+    value: ";",
+
+    range: [5, 6],
+    loc: {
+      start: { column: 5, line: 1 },
+      end: { column: 6, line: 1 },
+    },
+  },
+]
+`;
diff --git a/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/var-without-value/snapshots/5-AST-Alignment-AST.shot b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/var-without-value/snapshots/5-AST-Alignment-AST.shot
new file mode 100644
index 000000000000..b8594239a06c
--- /dev/null
+++ b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/var-without-value/snapshots/5-AST-Alignment-AST.shot
@@ -0,0 +1,6 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration VariableDeclaration var-without-value AST Alignment - AST 1`] = `
+"Snapshot Diff:
+Compared values have no visual difference."
+`;
diff --git a/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/var-without-value/snapshots/6-AST-Alignment-Tokens.shot b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/var-without-value/snapshots/6-AST-Alignment-Tokens.shot
new file mode 100644
index 000000000000..3d401ca8c69e
--- /dev/null
+++ b/packages/ast-spec/src/declaration/VariableDeclaration/fixtures/var-without-value/snapshots/6-AST-Alignment-Tokens.shot
@@ -0,0 +1,6 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AST Fixtures declaration VariableDeclaration var-without-value AST Alignment - Token 1`] = `
+"Snapshot Diff:
+Compared values have no visual difference."
+`;
diff --git a/packages/ast-spec/src/declaration/VariableDeclaration/spec.ts b/packages/ast-spec/src/declaration/VariableDeclaration/spec.ts
index 418a51eb735b..4bc9b0f48541 100644
--- a/packages/ast-spec/src/declaration/VariableDeclaration/spec.ts
+++ b/packages/ast-spec/src/declaration/VariableDeclaration/spec.ts
@@ -4,8 +4,31 @@ import type { VariableDeclarator } from '../../special/VariableDeclarator/spec';
 
 export interface VariableDeclaration extends BaseNode {
   type: AST_NODE_TYPES.VariableDeclaration;
-  // NOTE - this is not guaranteed to have any elements in it. i.e. `const;`
+  /**
+   * The variables declared by this declaration.
+   * Note that there may be 0 declarations (i.e. `const;`).
+   * ```
+   * let x;
+   * let y, z;
+   * ```
+   */
+  // TODO(#1852) - this should be guaranteed to have at least 1 element in it.
   declarations: VariableDeclarator[];
-  kind: 'const' | 'let' | 'var';
+  /**
+   * Whether the declaration is `declare`d
+   * ```
+   * declare const x = 1;
+   * ```
+   */
+  // TODO(#5020) - make this `false` if it is not `declare`d
   declare?: boolean;
+  /**
+   * The keyword used to declare the variable(s)
+   * ```
+   * const x = 1;
+   * let y = 2;
+   * var z = 3;
+   * ```
+   */
+  kind: 'const' | 'let' | 'var';
 }
diff --git a/packages/ast-spec/src/expression/ArrayExpression/spec.ts b/packages/ast-spec/src/expression/ArrayExpression/spec.ts
index 7da330e231a4..7dc07e30952b 100644
--- a/packages/ast-spec/src/expression/ArrayExpression/spec.ts
+++ b/packages/ast-spec/src/expression/ArrayExpression/spec.ts
@@ -1,8 +1,9 @@
 import type { AST_NODE_TYPES } from '../../ast-node-types';
 import type { BaseNode } from '../../base/BaseNode';
+import type { SpreadElement } from '../../element/SpreadElement/spec';
 import type { Expression } from '../../unions/Expression';
 
 export interface ArrayExpression extends BaseNode {
   type: AST_NODE_TYPES.ArrayExpression;
-  elements: Expression[];
+  elements: (Expression | SpreadElement)[];
 }
diff --git a/packages/ast-spec/src/expression/ClassExpression/spec.ts b/packages/ast-spec/src/expression/ClassExpression/spec.ts
index 15215c31f1b6..dfe6c0d1b41d 100644
--- a/packages/ast-spec/src/expression/ClassExpression/spec.ts
+++ b/packages/ast-spec/src/expression/ClassExpression/spec.ts
@@ -1,6 +1,9 @@
 import type { AST_NODE_TYPES } from '../../ast-node-types';
-import type { ClassDeclarationBase } from '../../base/ClassDeclarationBase';
+import type { ClassBase } from '../../base/ClassBase';
 
-export interface ClassExpression extends ClassDeclarationBase {
+export interface ClassExpression extends ClassBase {
   type: AST_NODE_TYPES.ClassExpression;
+  abstract?: undefined;
+  declare?: undefined;
+  decorators?: undefined;
 }
diff --git a/packages/ast-spec/src/expression/FunctionExpression/spec.ts b/packages/ast-spec/src/expression/FunctionExpression/spec.ts
index 111be168b024..41f592a972f0 100644
--- a/packages/ast-spec/src/expression/FunctionExpression/spec.ts
+++ b/packages/ast-spec/src/expression/FunctionExpression/spec.ts
@@ -1,8 +1,9 @@
 import type { AST_NODE_TYPES } from '../../ast-node-types';
-import type { FunctionDeclarationBase } from '../../base/FunctionDeclarationBase';
+import type { FunctionBase } from '../../base/FunctionBase';
 import type { BlockStatement } from '../../statement/BlockStatement/spec';
 
-export interface FunctionExpression extends FunctionDeclarationBase {
+export interface FunctionExpression extends FunctionBase {
   type: AST_NODE_TYPES.FunctionExpression;
   body: BlockStatement;
+  expression: false;
 }
diff --git a/packages/ast-spec/src/expression/TSEmptyBodyFunctionExpression/spec.ts b/packages/ast-spec/src/expression/TSEmptyBodyFunctionExpression/spec.ts
index 2cc413c01095..77c8779c7d14 100644
--- a/packages/ast-spec/src/expression/TSEmptyBodyFunctionExpression/spec.ts
+++ b/packages/ast-spec/src/expression/TSEmptyBodyFunctionExpression/spec.ts
@@ -1,7 +1,8 @@
 import type { AST_NODE_TYPES } from '../../ast-node-types';
-import type { FunctionDeclarationBase } from '../../base/FunctionDeclarationBase';
+import type { FunctionBase } from '../../base/FunctionBase';
 
-export interface TSEmptyBodyFunctionExpression extends FunctionDeclarationBase {
+export interface TSEmptyBodyFunctionExpression extends FunctionBase {
   type: AST_NODE_TYPES.TSEmptyBodyFunctionExpression;
   body: null;
+  id: null;
 }
diff --git a/packages/ast-spec/src/expression/TSInstantiationExpression/spec.ts b/packages/ast-spec/src/expression/TSInstantiationExpression/spec.ts
new file mode 100644
index 000000000000..c0a9f9fd99b7
--- /dev/null
+++ b/packages/ast-spec/src/expression/TSInstantiationExpression/spec.ts
@@ -0,0 +1,10 @@
+import type { AST_NODE_TYPES } from '../../ast-node-types';
+import type { BaseNode } from '../../base/BaseNode';
+import type { TSTypeParameterInstantiation } from '../../special/spec';
+import type { Expression } from '../../unions/Expression';
+
+export interface TSInstantiationExpression extends BaseNode {
+  type: AST_NODE_TYPES.TSInstantiationExpression;
+  expression: Expression;
+  typeParameters: TSTypeParameterInstantiation;
+}
diff --git a/packages/ast-spec/src/expression/spec.ts b/packages/ast-spec/src/expression/spec.ts
index 9ea054546202..9ed4a0cc7561 100644
--- a/packages/ast-spec/src/expression/spec.ts
+++ b/packages/ast-spec/src/expression/spec.ts
@@ -21,6 +21,7 @@ export * from './SequenceExpression/spec';
 export * from './Super/spec';
 export * from './TSAsExpression/spec';
 export * from './TSEmptyBodyFunctionExpression/spec';
+export * from './TSInstantiationExpression/spec';
 export * from './TSNonNullExpression/spec';
 export * from './TSTypeAssertion/spec';
 export * from './TaggedTemplateExpression/spec';
diff --git a/packages/ast-spec/src/special/TSExternalModuleReference/spec.ts b/packages/ast-spec/src/special/TSExternalModuleReference/spec.ts
index e634d4d0d6e9..1efd283fd8cf 100644
--- a/packages/ast-spec/src/special/TSExternalModuleReference/spec.ts
+++ b/packages/ast-spec/src/special/TSExternalModuleReference/spec.ts
@@ -4,5 +4,6 @@ import type { Expression } from '../../unions/Expression';
 
 export interface TSExternalModuleReference extends BaseNode {
   type: AST_NODE_TYPES.TSExternalModuleReference;
+  // TODO(#1852) - this must be a string
   expression: Expression;
 }
diff --git a/packages/ast-spec/src/special/TSTypeParameter/spec.ts b/packages/ast-spec/src/special/TSTypeParameter/spec.ts
index 61d75a6a29ed..7487e4f56177 100644
--- a/packages/ast-spec/src/special/TSTypeParameter/spec.ts
+++ b/packages/ast-spec/src/special/TSTypeParameter/spec.ts
@@ -8,4 +8,6 @@ export interface TSTypeParameter extends BaseNode {
   name: Identifier;
   constraint?: TypeNode;
   default?: TypeNode;
+  in: boolean;
+  out: boolean;
 }
diff --git a/packages/ast-spec/src/unions/ExportDeclaration.ts b/packages/ast-spec/src/unions/ExportDeclaration.ts
index 1ae9d9ddb9f8..b78996d14053 100644
--- a/packages/ast-spec/src/unions/ExportDeclaration.ts
+++ b/packages/ast-spec/src/unions/ExportDeclaration.ts
@@ -1,20 +1,48 @@
-import type { ClassDeclaration } from '../declaration/ClassDeclaration/spec';
-import type { FunctionDeclaration } from '../declaration/FunctionDeclaration/spec';
+import type {
+  ClassDeclarationWithName,
+  ClassDeclarationWithOptionalName,
+} from '../declaration/ClassDeclaration/spec';
+import type {
+  FunctionDeclarationWithName,
+  FunctionDeclarationWithOptionalName,
+} from '../declaration/FunctionDeclaration/spec';
 import type { TSDeclareFunction } from '../declaration/TSDeclareFunction/spec';
 import type { TSEnumDeclaration } from '../declaration/TSEnumDeclaration/spec';
 import type { TSInterfaceDeclaration } from '../declaration/TSInterfaceDeclaration/spec';
 import type { TSModuleDeclaration } from '../declaration/TSModuleDeclaration/spec';
 import type { TSTypeAliasDeclaration } from '../declaration/TSTypeAliasDeclaration/spec';
 import type { VariableDeclaration } from '../declaration/VariableDeclaration/spec';
-import type { ClassExpression } from '../expression/ClassExpression/spec';
+import type { Expression } from './Expression';
 
-export type ExportDeclaration =
-  | ClassDeclaration
-  | ClassExpression
-  | FunctionDeclaration
+// TODO(#1852) - the following are disallowed syntactically, but allowed by TS error recovery:
+// TSEnumDeclaration, TSModuleDeclaration, TSTypeAliasDeclaration, VariableDeclaration
+export type DefaultExportDeclarations =
+  | ClassDeclarationWithOptionalName
+  | Expression
+  | FunctionDeclarationWithName
+  | FunctionDeclarationWithOptionalName
+  | TSDeclareFunction
+  | TSEnumDeclaration
+  | TSInterfaceDeclaration
+  | TSModuleDeclaration
+  | TSTypeAliasDeclaration
+  | VariableDeclaration;
+
+// TODO(#1852) - the following are disallowed syntactically, but allowed by TS error recovery:
+// ClassDeclarationWithOptionalName, FunctionDeclarationWithOptionalName
+export type NamedExportDeclarations =
+  | ClassDeclarationWithName
+  | ClassDeclarationWithOptionalName
+  | FunctionDeclarationWithName
+  | FunctionDeclarationWithOptionalName
   | TSDeclareFunction
   | TSEnumDeclaration
   | TSInterfaceDeclaration
   | TSModuleDeclaration
   | TSTypeAliasDeclaration
   | VariableDeclaration;
+
+// TODO - breaking change remove this in the next major
+export type ExportDeclaration =
+  | DefaultExportDeclarations
+  | NamedExportDeclarations;
diff --git a/packages/ast-spec/src/unions/Expression.ts b/packages/ast-spec/src/unions/Expression.ts
index 5359dc9c69c7..36220bc03919 100644
--- a/packages/ast-spec/src/unions/Expression.ts
+++ b/packages/ast-spec/src/unions/Expression.ts
@@ -23,6 +23,7 @@ import type { TaggedTemplateExpression } from '../expression/TaggedTemplateExpre
 import type { TemplateLiteral } from '../expression/TemplateLiteral/spec';
 import type { ThisExpression } from '../expression/ThisExpression/spec';
 import type { TSAsExpression } from '../expression/TSAsExpression/spec';
+import type { TSInstantiationExpression } from '../expression/TSInstantiationExpression/spec';
 import type { TSNonNullExpression } from '../expression/TSNonNullExpression/spec';
 import type { TSTypeAssertion } from '../expression/TSTypeAssertion/spec';
 import type { UnaryExpression } from '../expression/UnaryExpression/spec';
@@ -69,6 +70,7 @@ export type Expression =
   | TemplateLiteral
   | ThisExpression
   | TSAsExpression
+  | TSInstantiationExpression
   | TSNonNullExpression
   | TSTypeAssertion
   | UnaryExpression
diff --git a/packages/ast-spec/src/unions/Node.ts b/packages/ast-spec/src/unions/Node.ts
index b031d3bd348e..f6d4cbafffd1 100644
--- a/packages/ast-spec/src/unions/Node.ts
+++ b/packages/ast-spec/src/unions/Node.ts
@@ -51,6 +51,7 @@ import type { TemplateLiteral } from '../expression/TemplateLiteral/spec';
 import type { ThisExpression } from '../expression/ThisExpression/spec';
 import type { TSAsExpression } from '../expression/TSAsExpression/spec';
 import type { TSEmptyBodyFunctionExpression } from '../expression/TSEmptyBodyFunctionExpression/spec';
+import type { TSInstantiationExpression } from '../expression/TSInstantiationExpression/spec';
 import type { TSNonNullExpression } from '../expression/TSNonNullExpression/spec';
 import type { TSTypeAssertion } from '../expression/TSTypeAssertion/spec';
 import type { UnaryExpression } from '../expression/UnaryExpression/spec';
@@ -277,6 +278,7 @@ export type Node =
   | TSIndexedAccessType
   | TSIndexSignature
   | TSInferType
+  | TSInstantiationExpression
   | TSInterfaceBody
   | TSInterfaceDeclaration
   | TSInterfaceHeritage
diff --git a/packages/ast-spec/src/unions/Statement.ts b/packages/ast-spec/src/unions/Statement.ts
index e1af96b7fe5d..56a4cfaf1ae9 100644
--- a/packages/ast-spec/src/unions/Statement.ts
+++ b/packages/ast-spec/src/unions/Statement.ts
@@ -1,8 +1,8 @@
-import type { ClassDeclaration } from '../declaration/ClassDeclaration/spec';
+import type { ClassDeclarationWithName } from '../declaration/ClassDeclaration/spec';
 import type { ExportAllDeclaration } from '../declaration/ExportAllDeclaration/spec';
 import type { ExportDefaultDeclaration } from '../declaration/ExportDefaultDeclaration/spec';
 import type { ExportNamedDeclaration } from '../declaration/ExportNamedDeclaration/spec';
-import type { FunctionDeclaration } from '../declaration/FunctionDeclaration/spec';
+import type { FunctionDeclarationWithName } from '../declaration/FunctionDeclaration/spec';
 import type { ImportDeclaration } from '../declaration/ImportDeclaration/spec';
 import type { TSDeclareFunction } from '../declaration/TSDeclareFunction/spec';
 import type { TSEnumDeclaration } from '../declaration/TSEnumDeclaration/spec';
@@ -34,7 +34,7 @@ import type { WithStatement } from '../statement/WithStatement/spec';
 export type Statement =
   | BlockStatement
   | BreakStatement
-  | ClassDeclaration
+  | ClassDeclarationWithName
   | ContinueStatement
   | DebuggerStatement
   | DoWhileStatement
@@ -45,7 +45,7 @@ export type Statement =
   | ForInStatement
   | ForOfStatement
   | ForStatement
-  | FunctionDeclaration
+  | FunctionDeclarationWithName
   | IfStatement
   | ImportDeclaration
   | LabeledStatement
@@ -75,4 +75,4 @@ export type ProgramStatement =
   | TSImportEqualsDeclaration
   | TSNamespaceExportDeclaration;
 
-// TODO - once we have syntax errors, the types in ProgramStatement should not be in Statement
+// TODO(#1852) - the types in ProgramStatement should not be in Statement
diff --git a/packages/ast-spec/tests/fixtures-with-differences-ast.shot b/packages/ast-spec/tests/fixtures-with-differences-ast.shot
index 2a37d6b6582d..9d3e5d88ccca 100644
--- a/packages/ast-spec/tests/fixtures-with-differences-ast.shot
+++ b/packages/ast-spec/tests/fixtures-with-differences-ast.shot
@@ -4,13 +4,25 @@ exports[`AST Fixtures List fixtures with AST differences 1`] = `
 Set {
   "declaration/ClassDeclaration/fixtures/implements-many/fixture.ts",
   "declaration/ClassDeclaration/fixtures/implements-one/fixture.ts",
-  "declaration/ClassDeclaration/fixtures/type-parameters-extends-type-parameters/fixture.ts",
-  "declaration/ClassDeclaration/fixtures/type-parameters/fixture.ts",
+  "declaration/ClassDeclaration/fixtures/type-param/fixture.ts",
+  "declaration/ClassDeclaration/fixtures/type-parameters-extends-type-param/fixture.ts",
+  "declaration/ClassDeclaration/fixtures/with-member-one/fixture.ts",
   "declaration/ExportNamedDeclaration/fixtures/aliased/fixture.ts",
   "declaration/ExportNamedDeclaration/fixtures/declare-function/fixture.ts",
   "declaration/ExportNamedDeclaration/fixtures/identifier-braced/fixture.ts",
   "declaration/ExportNamedDeclaration/fixtures/identifier-many/fixture.ts",
   "declaration/ExportNamedDeclaration/fixtures/interface/fixture.ts",
   "declaration/ExportNamedDeclaration/fixtures/type-alias/fixture.ts",
+  "declaration/FunctionDeclaration/fixtures/type-param-many/fixture.ts",
+  "declaration/FunctionDeclaration/fixtures/type-param-one/fixture.ts",
+  "declaration/TSDeclareFunction/fixtures/type-param-many/fixture.ts",
+  "declaration/TSDeclareFunction/fixtures/type-param-one/fixture.ts",
+  "declaration/TSImportEqualsDeclaration/fixtures/external-module-ref-string/fixture.ts",
+  "declaration/TSInterfaceDeclaration/fixtures/extends-many/fixture.ts",
+  "declaration/TSInterfaceDeclaration/fixtures/extends-one/fixture.ts",
+  "declaration/TSInterfaceDeclaration/fixtures/type-param-many/fixture.ts",
+  "declaration/TSInterfaceDeclaration/fixtures/type-param-one/fixture.ts",
+  "declaration/TSTypeAliasDeclaration/fixtures/type-param-many/fixture.ts",
+  "declaration/TSTypeAliasDeclaration/fixtures/type-param-one/fixture.ts",
 }
 `;
diff --git a/packages/ast-spec/tests/fixtures-with-differences-errors.shot b/packages/ast-spec/tests/fixtures-with-differences-errors.shot
index 59b5c479a758..f9c7ef6147dd 100644
--- a/packages/ast-spec/tests/fixtures-with-differences-errors.shot
+++ b/packages/ast-spec/tests/fixtures-with-differences-errors.shot
@@ -4,8 +4,22 @@ exports[`AST Fixtures List fixtures with Error differences 1`] = `
 Object {
   "Babel errored but TSESTree didn't": Set {
     "declaration/ClassDeclaration/fixtures/_error_/implements-non-identifier/fixture.ts",
+    "declaration/ClassDeclaration/fixtures/_error_/missing-extends-type-param/fixture.ts",
+    "declaration/ClassDeclaration/fixtures/_error_/missing-type-param/fixture.ts",
+    "declaration/ExportAllDeclaration/fixtures/_error_/kind-type/fixture.ts",
     "declaration/ExportAllDeclaration/fixtures/_error_/type-kind/fixture.ts",
     "declaration/ExportNamedDeclaration/fixtures/_error_/anonymous-class/fixture.ts",
+    "declaration/FunctionDeclaration/fixtures/_error_/missing-type-param/fixture.ts",
+    "declaration/TSDeclareFunction/fixtures/_error_/async/fixture.ts",
+    "declaration/TSDeclareFunction/fixtures/_error_/declare-with-body/fixture.ts",
+    "declaration/TSDeclareFunction/fixtures/_error_/missing-type-param/fixture.ts",
+    "declaration/TSImportEqualsDeclaration/fixtures/_error_/external-module-ref-non-string/fixture.ts",
+    "declaration/TSImportEqualsDeclaration/fixtures/_error_/import-kind/fixture.ts",
+    "declaration/TSInterfaceDeclaration/fixtures/_error_/missing-extends/fixture.ts",
+    "declaration/TSInterfaceDeclaration/fixtures/_error_/missing-type-param/fixture.ts",
+    "declaration/TSInterfaceDeclaration/fixtures/_error_/non-identifier-extends/fixture.ts",
+    "declaration/TSTypeAliasDeclaration/fixtures/_error_/missing-type-parameter/fixture.ts",
+    "declaration/VariableDeclaration/fixtures/_error_/missing-id-without-value/fixture.ts",
   },
   "TSESTree errored but Babel didn't": Set {
     "declaration/ExportAllDeclaration/fixtures/_error_/named-non-identifier/fixture.ts",
diff --git a/packages/ast-spec/tests/fixtures-with-differences-tokens.shot b/packages/ast-spec/tests/fixtures-with-differences-tokens.shot
index 6c8d721a41a5..ee92fc9b050c 100644
--- a/packages/ast-spec/tests/fixtures-with-differences-tokens.shot
+++ b/packages/ast-spec/tests/fixtures-with-differences-tokens.shot
@@ -7,5 +7,20 @@ Set {
   "declaration/ExportDefaultDeclaration/fixtures/interface/fixture.ts",
   "declaration/ExportNamedDeclaration/fixtures/enum/fixture.ts",
   "declaration/ExportNamedDeclaration/fixtures/interface/fixture.ts",
+  "declaration/TSEnumDeclaration/fixtures/const/fixture.ts",
+  "declaration/TSEnumDeclaration/fixtures/declare/fixture.ts",
+  "declaration/TSEnumDeclaration/fixtures/empty/fixture.ts",
+  "declaration/TSEnumDeclaration/fixtures/with-member-one/fixture.ts",
+  "declaration/TSInterfaceDeclaration/fixtures/declare/fixture.ts",
+  "declaration/TSInterfaceDeclaration/fixtures/empty/fixture.ts",
+  "declaration/TSInterfaceDeclaration/fixtures/extends-many/fixture.ts",
+  "declaration/TSInterfaceDeclaration/fixtures/extends-one/fixture.ts",
+  "declaration/TSInterfaceDeclaration/fixtures/type-param-many/fixture.ts",
+  "declaration/TSInterfaceDeclaration/fixtures/type-param-one/fixture.ts",
+  "declaration/TSInterfaceDeclaration/fixtures/with-member-one/fixture.ts",
+  "declaration/VariableDeclaration/fixtures/declare/fixture.ts",
+  "declaration/VariableDeclaration/fixtures/let-with-value/fixture.ts",
+  "declaration/VariableDeclaration/fixtures/let-without-value/fixture.ts",
+  "declaration/VariableDeclaration/fixtures/multiple-declarations/fixture.ts",
 }
 `;
diff --git a/packages/eslint-plugin-internal/CHANGELOG.md b/packages/eslint-plugin-internal/CHANGELOG.md
index 20ecffa98294..708dc230e7c0 100644
--- a/packages/eslint-plugin-internal/CHANGELOG.md
+++ b/packages/eslint-plugin-internal/CHANGELOG.md
@@ -3,6 +3,14 @@
 All notable changes to this project will be documented in this file.
 See [Conventional Commits](https://conventionalcommits.org) for commit guidelines.
 
+# [5.26.0](https://github.com/typescript-eslint/typescript-eslint/compare/v5.25.0...v5.26.0) (2022-05-23)
+
+**Note:** Version bump only for package @typescript-eslint/eslint-plugin-internal
+
+
+
+
+
 # [5.25.0](https://github.com/typescript-eslint/typescript-eslint/compare/v5.24.0...v5.25.0) (2022-05-17)
 
 **Note:** Version bump only for package @typescript-eslint/eslint-plugin-internal
diff --git a/packages/eslint-plugin-internal/jest.config.js b/packages/eslint-plugin-internal/jest.config.js
index 5f1ea3f4bcb0..910991b20cff 100644
--- a/packages/eslint-plugin-internal/jest.config.js
+++ b/packages/eslint-plugin-internal/jest.config.js
@@ -4,5 +4,4 @@
 /** @type {import('@jest/types').Config.InitialOptions} */
 module.exports = {
   ...require('../../jest.config.base.js'),
-  testRegex: './tests/.+\\.test\\.ts$',
 };
diff --git a/packages/eslint-plugin-internal/package.json b/packages/eslint-plugin-internal/package.json
index 1329c7b60cdc..9bbcb633b100 100644
--- a/packages/eslint-plugin-internal/package.json
+++ b/packages/eslint-plugin-internal/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@typescript-eslint/eslint-plugin-internal",
-  "version": "5.25.0",
+  "version": "5.26.0",
   "private": true,
   "main": "dist/index.js",
   "scripts": {
@@ -14,8 +14,8 @@
   },
   "dependencies": {
     "@types/prettier": "*",
-    "@typescript-eslint/scope-manager": "5.25.0",
-    "@typescript-eslint/utils": "5.25.0",
+    "@typescript-eslint/scope-manager": "5.26.0",
+    "@typescript-eslint/utils": "5.26.0",
     "prettier": "*"
   }
 }
diff --git a/packages/eslint-plugin-tslint/CHANGELOG.md b/packages/eslint-plugin-tslint/CHANGELOG.md
index 7d01d518b2fa..b03e61eb79b1 100644
--- a/packages/eslint-plugin-tslint/CHANGELOG.md
+++ b/packages/eslint-plugin-tslint/CHANGELOG.md
@@ -3,6 +3,14 @@
 All notable changes to this project will be documented in this file.
 See [Conventional Commits](https://conventionalcommits.org) for commit guidelines.
 
+# [5.26.0](https://github.com/typescript-eslint/typescript-eslint/compare/v5.25.0...v5.26.0) (2022-05-23)
+
+**Note:** Version bump only for package @typescript-eslint/eslint-plugin-tslint
+
+
+
+
+
 # [5.25.0](https://github.com/typescript-eslint/typescript-eslint/compare/v5.24.0...v5.25.0) (2022-05-17)
 
 **Note:** Version bump only for package @typescript-eslint/eslint-plugin-tslint
diff --git a/packages/eslint-plugin-tslint/jest.config.js b/packages/eslint-plugin-tslint/jest.config.js
index 821770114b26..910991b20cff 100644
--- a/packages/eslint-plugin-tslint/jest.config.js
+++ b/packages/eslint-plugin-tslint/jest.config.js
@@ -4,5 +4,4 @@
 /** @type {import('@jest/types').Config.InitialOptions} */
 module.exports = {
   ...require('../../jest.config.base.js'),
-  testRegex: './tests/.+\\.spec\\.ts$',
 };
diff --git a/packages/eslint-plugin-tslint/package.json b/packages/eslint-plugin-tslint/package.json
index 77ebaade61ee..710adf382ea6 100644
--- a/packages/eslint-plugin-tslint/package.json
+++ b/packages/eslint-plugin-tslint/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@typescript-eslint/eslint-plugin-tslint",
-  "version": "5.25.0",
+  "version": "5.26.0",
   "main": "dist/index.js",
   "typings": "src/index.ts",
   "description": "TSLint wrapper plugin for ESLint",
@@ -38,7 +38,7 @@
     "typecheck": "tsc -p tsconfig.json --noEmit"
   },
   "dependencies": {
-    "@typescript-eslint/utils": "5.25.0",
+    "@typescript-eslint/utils": "5.26.0",
     "lodash": "^4.17.21"
   },
   "peerDependencies": {
@@ -48,6 +48,6 @@
   },
   "devDependencies": {
     "@types/lodash": "*",
-    "@typescript-eslint/parser": "5.25.0"
+    "@typescript-eslint/parser": "5.26.0"
   }
 }
diff --git a/packages/eslint-plugin/CHANGELOG.md b/packages/eslint-plugin/CHANGELOG.md
index 8c4ca25501f0..9ff900c12d32 100644
--- a/packages/eslint-plugin/CHANGELOG.md
+++ b/packages/eslint-plugin/CHANGELOG.md
@@ -3,6 +3,19 @@
 All notable changes to this project will be documented in this file.
 See [Conventional Commits](https://conventionalcommits.org) for commit guidelines.
 
+# [5.26.0](https://github.com/typescript-eslint/typescript-eslint/compare/v5.25.0...v5.26.0) (2022-05-23)
+
+
+### Bug Fixes
+
+* **eslint-plugin:** [member-delimiter-style] autofixer result is not as expected when comments after the delimiter with option `delimiter: 'none'` ([#5029](https://github.com/typescript-eslint/typescript-eslint/issues/5029)) ([ed7b5f6](https://github.com/typescript-eslint/typescript-eslint/commit/ed7b5f61d93799fec3e38a87935ab9caa3abe279))
+* **eslint-plugin:** [member-delimiter-style] autofixer result is not as expected with option `delimiter: 'none'` ([#5023](https://github.com/typescript-eslint/typescript-eslint/issues/5023)) ([9e97a11](https://github.com/typescript-eslint/typescript-eslint/commit/9e97a11ecd80be5c63c980bfe8d8e57400221cec))
+* **eslint-plugin:** [prefer-readonly] correct issue with anonymus functions ([#4974](https://github.com/typescript-eslint/typescript-eslint/issues/4974)) ([952e2f0](https://github.com/typescript-eslint/typescript-eslint/commit/952e2f068862dde089ec03d3eb5452d1ee3e9271)), closes [#2590](https://github.com/typescript-eslint/typescript-eslint/issues/2590)
+
+
+
+
+
 # [5.25.0](https://github.com/typescript-eslint/typescript-eslint/compare/v5.24.0...v5.25.0) (2022-05-17)
 
 
diff --git a/packages/eslint-plugin/docs/rules/README.md b/packages/eslint-plugin/docs/rules/README.md
index 94793a6fa011..0558f7195afd 100644
--- a/packages/eslint-plugin/docs/rules/README.md
+++ b/packages/eslint-plugin/docs/rules/README.md
@@ -39,7 +39,7 @@ See [Configs](/docs/linting/configs) for how to enable recommended rules using c
 | [`@typescript-eslint/no-base-to-string`](./no-base-to-string.md)                                             | Requires that `.toString()` is only called on objects which provide useful information when stringified                 | :lock:                   |          | :thought_balloon: |
 | [`@typescript-eslint/no-confusing-non-null-assertion`](./no-confusing-non-null-assertion.md)                 | Disallow non-null assertion in locations that may be confusing                                                          | :lock:                   | :wrench: |                   |
 | [`@typescript-eslint/no-confusing-void-expression`](./no-confusing-void-expression.md)                       | Requires expressions of type void to appear in statement position                                                       |                          | :wrench: | :thought_balloon: |
-| [`@typescript-eslint/no-duplicate-enum-values`](./docs/rules/no-duplicate-enum-values.md)                    | Disallow duplicate enum member values                                                                                   | :lock:                   |          |                   |
+| [`@typescript-eslint/no-duplicate-enum-values`](./no-duplicate-enum-values.md)                               | Disallow duplicate enum member values                                                                                   | :lock:                   |          |                   |
 | [`@typescript-eslint/no-dynamic-delete`](./no-dynamic-delete.md)                                             | Disallow the delete operator with computed key expressions                                                              | :lock:                   | :wrench: |                   |
 | [`@typescript-eslint/no-empty-interface`](./no-empty-interface.md)                                           | Disallow the declaration of empty interfaces                                                                            | :white_check_mark:       | :wrench: |                   |
 | [`@typescript-eslint/no-explicit-any`](./no-explicit-any.md)                                                 | Disallow usage of the `any` type                                                                                        | :white_check_mark:       | :wrench: |                   |
diff --git a/packages/eslint-plugin/docs/rules/ban-types.md b/packages/eslint-plugin/docs/rules/ban-types.md
index b83186fe7476..3189c086a1cc 100644
--- a/packages/eslint-plugin/docs/rules/ban-types.md
+++ b/packages/eslint-plugin/docs/rules/ban-types.md
@@ -27,17 +27,27 @@ type Options = {
 };
 ```
 
-The rule accepts a single object as options, with the following keys:
-
-- `types` - An object whose keys are the types you want to ban, and the values are error messages.
-  - The type can either be a type name literal (`Foo`), a type name with generic parameter instantiation(s) (`Foo<Bar>`), the empty object literal (`{}`), or the empty tuple type (`[]`).
-  - The values can be a string, which is the error message to be reported, `false` to specifically disable this type
-    or it can be an object with the following properties:
-    - `message: string` - the message to display when the type is matched.
-    - `fixWith?: string` - a string to replace the banned type with when the fixer is run. If this is omitted, no fix will be done.
-- `extendDefaults` - if you're specifying custom `types`, you can set this to `true` to extend the default `types` configuration.
-  - This is a convenience option to save you copying across the defaults when adding another type.
-  - If this is `false`, the rule will _only_ use the types defined in your configuration.
+The rule accepts a single object as options.
+
+### `types`
+
+An object whose keys are the types you want to ban, and the values are error messages.
+
+The type can either be a type name literal (`Foo`), a type name with generic parameter instantiation(s) (`Foo<Bar>`), the empty object literal (`{}`), or the empty tuple type (`[]`).
+
+The values can be:
+
+- A string, which is the error message to be reported; or
+- `false` to specifically un-ban this type (useful when you are using `extendDefaults`); or
+- An object with the following properties:
+  - `message: string` - the message to display when the type is matched.
+  - `fixWith?: string` - a string to replace the banned type with when the fixer is run. If this is omitted, no fix will be done.
+
+### `extendDefaults`
+
+If you're specifying custom `types`, you can set this to `true` to extend the default `types` configuration. This is a convenience option to save you copying across the defaults when adding another type.
+
+If this is `false`, the rule will _only_ use the types defined in your configuration.
 
 Example configuration:
 
@@ -51,16 +61,15 @@ Example configuration:
         "Foo": "Don't use Foo because it is unsafe",
 
         // add a custom message, AND tell the plugin how to fix it
-        "String": {
-          "message": "Use string instead",
-          "fixWith": "string"
+        "OldAPI": {
+          "message": "Use NewAPI instead",
+          "fixWith": "NewAPI"
         },
 
-        "{}": {
-          "message": "Use object instead",
-          "fixWith": "object"
-        }
-      }
+        // un-ban a type that's banned by default
+        "{}": false
+      },
+      "extendsDefaults": true
     }
   ]
 }
diff --git a/packages/eslint-plugin/docs/rules/triple-slash-reference.md b/packages/eslint-plugin/docs/rules/triple-slash-reference.md
index 2488d28ab135..d15d1cc5e129 100644
--- a/packages/eslint-plugin/docs/rules/triple-slash-reference.md
+++ b/packages/eslint-plugin/docs/rules/triple-slash-reference.md
@@ -44,6 +44,22 @@ import * as foo from 'foo';
 import foo = require('foo');
 ```
 
+## Options
+
+```ts
+type Options = {
+  lib?: 'always' | 'never';
+  path?: 'always' | 'never';
+  types?: 'always' | 'never' | 'prefer-import';
+};
+
+const defaultOptions: Options = {
+  lib: 'always',
+  path: 'never',
+  types: 'prefer-import',
+};
+```
+
 ## When To Use It
 
 If you want to ban use of one or all of the triple slash reference directives, or any time you might use triple-slash type reference directives and ES6 import declarations in the same file.
diff --git a/packages/eslint-plugin/jest.config.js b/packages/eslint-plugin/jest.config.js
index 1f9cdcdecd92..910991b20cff 100644
--- a/packages/eslint-plugin/jest.config.js
+++ b/packages/eslint-plugin/jest.config.js
@@ -4,6 +4,4 @@
 /** @type {import('@jest/types').Config.InitialOptions} */
 module.exports = {
   ...require('../../jest.config.base.js'),
-  testRegex: './tests/.+\\.test\\.ts$',
-  coverageReporters: ['text-summary', 'lcov'],
 };
diff --git a/packages/eslint-plugin/package.json b/packages/eslint-plugin/package.json
index 00acf3790485..9356f6b326f9 100644
--- a/packages/eslint-plugin/package.json
+++ b/packages/eslint-plugin/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@typescript-eslint/eslint-plugin",
-  "version": "5.25.0",
+  "version": "5.26.0",
   "description": "TypeScript plugin for ESLint",
   "keywords": [
     "eslint",
@@ -44,9 +44,9 @@
     "typecheck": "tsc -p tsconfig.json --noEmit"
   },
   "dependencies": {
-    "@typescript-eslint/scope-manager": "5.25.0",
-    "@typescript-eslint/type-utils": "5.25.0",
-    "@typescript-eslint/utils": "5.25.0",
+    "@typescript-eslint/scope-manager": "5.26.0",
+    "@typescript-eslint/type-utils": "5.26.0",
+    "@typescript-eslint/utils": "5.26.0",
     "debug": "^4.3.4",
     "functional-red-black-tree": "^1.0.1",
     "ignore": "^5.2.0",
diff --git a/packages/eslint-plugin/src/rules/member-delimiter-style.ts b/packages/eslint-plugin/src/rules/member-delimiter-style.ts
index e35b6459de8a..2919a2091f62 100644
--- a/packages/eslint-plugin/src/rules/member-delimiter-style.ts
+++ b/packages/eslint-plugin/src/rules/member-delimiter-style.ts
@@ -35,6 +35,7 @@ interface MakeFixFunctionParams {
   optsNone: boolean;
   optsSemi: boolean;
   lastToken: LastTokenType;
+  commentsAfterLastToken: LastTokenType | undefined;
   missingDelimiter: boolean;
   lastTokenLine: string;
   isSingleLine: boolean;
@@ -68,16 +69,35 @@ const definition = {
   additionalProperties: false,
 };
 
-const isLastTokenEndOfLine = (token: string, line: string): boolean => {
-  const positionInLine = line.indexOf(token);
+const isLastTokenEndOfLine = (token: LastTokenType, line: string): boolean => {
+  const positionInLine = token.loc.start.column;
 
   return positionInLine === line.length - 1;
 };
 
+const isCommentsEndOfLine = (
+  token: LastTokenType,
+  comments: LastTokenType | undefined,
+  line: string,
+): boolean => {
+  if (!comments) {
+    return false;
+  }
+
+  if (comments.loc.end.line > token.loc.end.line) {
+    return true;
+  }
+
+  const positionInLine = comments.loc.end.column;
+
+  return positionInLine === line.length;
+};
+
 const makeFixFunction = ({
   optsNone,
   optsSemi,
   lastToken,
+  commentsAfterLastToken,
   missingDelimiter,
   lastTokenLine,
   isSingleLine,
@@ -85,7 +105,8 @@ const makeFixFunction = ({
   // if removing is the action but last token is not the end of the line
   if (
     optsNone &&
-    !isLastTokenEndOfLine(lastToken.value, lastTokenLine) &&
+    !isLastTokenEndOfLine(lastToken, lastTokenLine) &&
+    !isCommentsEndOfLine(lastToken, commentsAfterLastToken, lastTokenLine) &&
     !isSingleLine
   ) {
     return null;
@@ -206,6 +227,10 @@ export default util.createRule<Options, MessageIds>({
         return;
       }
 
+      const commentsAfterLastToken = sourceCode
+        .getCommentsAfter(lastToken)
+        .pop();
+
       const sourceCodeLines = sourceCode.getLines();
       const lastTokenLine = sourceCodeLines[lastToken?.loc.start.line - 1];
 
@@ -255,6 +280,7 @@ export default util.createRule<Options, MessageIds>({
             optsNone,
             optsSemi,
             lastToken,
+            commentsAfterLastToken,
             missingDelimiter,
             lastTokenLine,
             isSingleLine: opts.type === 'single-line',
diff --git a/packages/eslint-plugin/src/rules/prefer-readonly.ts b/packages/eslint-plugin/src/rules/prefer-readonly.ts
index 19597264bbcb..816a79371fbe 100644
--- a/packages/eslint-plugin/src/rules/prefer-readonly.ts
+++ b/packages/eslint-plugin/src/rules/prefer-readonly.ts
@@ -270,8 +270,12 @@ class ClassScope {
     classNode: ts.ClassLikeDeclaration,
     private readonly onlyInlineLambdas?: boolean,
   ) {
-    this.checker = checker;
-    this.classType = checker.getTypeAtLocation(classNode);
+    const classType = checker.getTypeAtLocation(classNode);
+    if (tsutils.isIntersectionType(classType)) {
+      this.classType = classType.types[0];
+    } else {
+      this.classType = classType;
+    }
 
     for (const member of classNode.members) {
       if (ts.isPropertyDeclaration(member)) {
diff --git a/packages/eslint-plugin/tests/rules/member-delimiter-style.test.ts b/packages/eslint-plugin/tests/rules/member-delimiter-style.test.ts
index fa75383df8e3..1b618448a93c 100644
--- a/packages/eslint-plugin/tests/rules/member-delimiter-style.test.ts
+++ b/packages/eslint-plugin/tests/rules/member-delimiter-style.test.ts
@@ -3548,5 +3548,79 @@ type Foo = {a: {
         },
       ],
     },
+    {
+      code: `
+type Foo = {
+  a: {
+    b: true;
+  }; c: false;
+}
+      `,
+      output: `
+type Foo = {
+  a: {
+    b: true
+  }; c: false
+}
+      `,
+      options: [
+        {
+          multiline: { delimiter: 'none' },
+        },
+      ],
+      errors: [
+        {
+          messageId: 'unexpectedSemi',
+          line: 4,
+          column: 13,
+        },
+        {
+          messageId: 'unexpectedSemi',
+          line: 5,
+          column: 5,
+        },
+        {
+          messageId: 'unexpectedSemi',
+          line: 5,
+          column: 15,
+        },
+      ],
+    },
+    {
+      code: `
+type Foo = {
+  a: true; /** something */ /** some
+  thing */ b: true; /** something */ c: false; // something
+}
+      `,
+      output: `
+type Foo = {
+  a: true /** something */ /** some
+  thing */ b: true; /** something */ c: false // something
+}
+      `,
+      options: [
+        {
+          multiline: { delimiter: 'none' },
+        },
+      ],
+      errors: [
+        {
+          messageId: 'unexpectedSemi',
+          line: 3,
+          column: 11,
+        },
+        {
+          messageId: 'unexpectedSemi',
+          line: 4,
+          column: 20,
+        },
+        {
+          messageId: 'unexpectedSemi',
+          line: 4,
+          column: 47,
+        },
+      ],
+    },
   ],
 });
diff --git a/packages/eslint-plugin/tests/rules/prefer-readonly.test.ts b/packages/eslint-plugin/tests/rules/prefer-readonly.test.ts
index c1602f019134..91e8213da579 100644
--- a/packages/eslint-plugin/tests/rules/prefer-readonly.test.ts
+++ b/packages/eslint-plugin/tests/rules/prefer-readonly.test.ts
@@ -292,6 +292,19 @@ class Foo {
     },
     {
       code: `
+function ClassWithName<TBase extends new (...args: any[]) => {}>(Base: TBase) {
+  return class extends Base {
+    private _name: string;
+
+    public test(value: string) {
+      this._name = value;
+    }
+  };
+}
+      `,
+    },
+    {
+      code: `
 class Foo {
   private value: Record<string, number> = {};
 
@@ -704,5 +717,30 @@ class Foo {
         }
       `,
     },
+    {
+      code: `
+function ClassWithName<TBase extends new (...args: any[]) => {}>(Base: TBase) {
+  return class extends Base {
+    private _name: string;
+  };
+}
+      `,
+      output: `
+function ClassWithName<TBase extends new (...args: any[]) => {}>(Base: TBase) {
+  return class extends Base {
+    private readonly _name: string;
+  };
+}
+      `,
+      errors: [
+        {
+          data: {
+            name: '_name',
+          },
+          line: 4,
+          messageId: 'preferReadonly',
+        },
+      ],
+    },
   ],
 });
diff --git a/packages/experimental-utils/CHANGELOG.md b/packages/experimental-utils/CHANGELOG.md
index 486ed3097f71..feed203c699a 100644
--- a/packages/experimental-utils/CHANGELOG.md
+++ b/packages/experimental-utils/CHANGELOG.md
@@ -3,6 +3,14 @@
 All notable changes to this project will be documented in this file.
 See [Conventional Commits](https://conventionalcommits.org) for commit guidelines.
 
+# [5.26.0](https://github.com/typescript-eslint/typescript-eslint/compare/v5.25.0...v5.26.0) (2022-05-23)
+
+**Note:** Version bump only for package @typescript-eslint/experimental-utils
+
+
+
+
+
 # [5.25.0](https://github.com/typescript-eslint/typescript-eslint/compare/v5.24.0...v5.25.0) (2022-05-17)
 
 **Note:** Version bump only for package @typescript-eslint/experimental-utils
diff --git a/packages/experimental-utils/package.json b/packages/experimental-utils/package.json
index b8e1d9ec230f..beaad1f279d6 100644
--- a/packages/experimental-utils/package.json
+++ b/packages/experimental-utils/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@typescript-eslint/experimental-utils",
-  "version": "5.25.0",
+  "version": "5.26.0",
   "description": "(Experimental) Utilities for working with TypeScript + ESLint together",
   "keywords": [
     "eslint",
@@ -38,7 +38,7 @@
     "typecheck": "tsc -p tsconfig.json --noEmit"
   },
   "dependencies": {
-    "@typescript-eslint/utils": "5.25.0"
+    "@typescript-eslint/utils": "5.26.0"
   },
   "peerDependencies": {
     "eslint": "^6.0.0 || ^7.0.0 || ^8.0.0"
diff --git a/packages/parser/CHANGELOG.md b/packages/parser/CHANGELOG.md
index 2ff32ebf9f81..d832453d454b 100644
--- a/packages/parser/CHANGELOG.md
+++ b/packages/parser/CHANGELOG.md
@@ -3,6 +3,14 @@
 All notable changes to this project will be documented in this file.
 See [Conventional Commits](https://conventionalcommits.org) for commit guidelines.
 
+# [5.26.0](https://github.com/typescript-eslint/typescript-eslint/compare/v5.25.0...v5.26.0) (2022-05-23)
+
+**Note:** Version bump only for package @typescript-eslint/parser
+
+
+
+
+
 # [5.25.0](https://github.com/typescript-eslint/typescript-eslint/compare/v5.24.0...v5.25.0) (2022-05-17)
 
 **Note:** Version bump only for package @typescript-eslint/parser
diff --git a/packages/parser/package.json b/packages/parser/package.json
index 7b98529b475d..fcb40066bf43 100644
--- a/packages/parser/package.json
+++ b/packages/parser/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@typescript-eslint/parser",
-  "version": "5.25.0",
+  "version": "5.26.0",
   "description": "An ESLint custom parser which leverages TypeScript ESTree",
   "main": "dist/index.js",
   "types": "dist/index.d.ts",
@@ -44,9 +44,9 @@
     "eslint": "^6.0.0 || ^7.0.0 || ^8.0.0"
   },
   "dependencies": {
-    "@typescript-eslint/scope-manager": "5.25.0",
-    "@typescript-eslint/types": "5.25.0",
-    "@typescript-eslint/typescript-estree": "5.25.0",
+    "@typescript-eslint/scope-manager": "5.26.0",
+    "@typescript-eslint/types": "5.26.0",
+    "@typescript-eslint/typescript-estree": "5.26.0",
     "debug": "^4.3.4"
   },
   "devDependencies": {
diff --git a/packages/scope-manager/CHANGELOG.md b/packages/scope-manager/CHANGELOG.md
index 17df5044b7b5..96e2f4e18e49 100644
--- a/packages/scope-manager/CHANGELOG.md
+++ b/packages/scope-manager/CHANGELOG.md
@@ -3,6 +3,14 @@
 All notable changes to this project will be documented in this file.
 See [Conventional Commits](https://conventionalcommits.org) for commit guidelines.
 
+# [5.26.0](https://github.com/typescript-eslint/typescript-eslint/compare/v5.25.0...v5.26.0) (2022-05-23)
+
+**Note:** Version bump only for package @typescript-eslint/scope-manager
+
+
+
+
+
 # [5.25.0](https://github.com/typescript-eslint/typescript-eslint/compare/v5.24.0...v5.25.0) (2022-05-17)
 
 
diff --git a/packages/scope-manager/jest.config.js b/packages/scope-manager/jest.config.js
index ccaa4a6999bb..9148e4d46fb7 100644
--- a/packages/scope-manager/jest.config.js
+++ b/packages/scope-manager/jest.config.js
@@ -1,19 +1,8 @@
 'use strict';
 
 // @ts-check
-
 /** @type {import('@jest/types').Config.InitialOptions} */
 module.exports = {
-  displayName: 'scope-manager',
-  preset: '../../jest.preset.js',
-  testEnvironment: 'node',
-  transform: {
-    '^.+\\.[tj]sx?$': [
-      '@swc/jest',
-      { jsc: { transform: { react: { runtime: 'automatic' } } } },
-    ],
-  },
-  moduleFileExtensions: ['ts', 'tsx', 'js', 'jsx'],
-  coverageDirectory: '<rootDir>/coverage',
+  ...require('../../jest.config.base.js'),
   setupFilesAfterEnv: ['./tests/util/serializers/index.ts'],
 };
diff --git a/packages/scope-manager/package.json b/packages/scope-manager/package.json
index 90e900573251..e45e825f30a0 100644
--- a/packages/scope-manager/package.json
+++ b/packages/scope-manager/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@typescript-eslint/scope-manager",
-  "version": "5.25.0",
+  "version": "5.26.0",
   "description": "TypeScript scope analyser for ESLint",
   "keywords": [
     "eslint",
@@ -38,12 +38,12 @@
     "typecheck": "cd ../../ && nx typecheck @typescript-eslint/scope-manager"
   },
   "dependencies": {
-    "@typescript-eslint/types": "5.25.0",
-    "@typescript-eslint/visitor-keys": "5.25.0"
+    "@typescript-eslint/types": "5.26.0",
+    "@typescript-eslint/visitor-keys": "5.26.0"
   },
   "devDependencies": {
     "@types/glob": "*",
-    "@typescript-eslint/typescript-estree": "5.25.0",
+    "@typescript-eslint/typescript-estree": "5.26.0",
     "glob": "*",
     "jest-specific-snapshot": "*",
     "make-dir": "*",
diff --git a/packages/shared-fixtures/CHANGELOG.md b/packages/shared-fixtures/CHANGELOG.md
index 1588386a06b5..2b4c428a0599 100644
--- a/packages/shared-fixtures/CHANGELOG.md
+++ b/packages/shared-fixtures/CHANGELOG.md
@@ -3,6 +3,19 @@
 All notable changes to this project will be documented in this file.
 See [Conventional Commits](https://conventionalcommits.org) for commit guidelines.
 
+# [5.26.0](https://github.com/typescript-eslint/typescript-eslint/compare/v5.25.0...v5.26.0) (2022-05-23)
+
+
+### Features
+
+* [4.7] support instantiation expressions ([#4938](https://github.com/typescript-eslint/typescript-eslint/issues/4938)) ([79fbc77](https://github.com/typescript-eslint/typescript-eslint/commit/79fbc7743ae5dce3190f8168776e0204755390ad))
+* [4.7] support optional variance annotation ([#4831](https://github.com/typescript-eslint/typescript-eslint/issues/4831)) ([7e7b24c](https://github.com/typescript-eslint/typescript-eslint/commit/7e7b24c196e6d968e48f97f46feae5e7027e22d2))
+* **typescript-estree:** `extends` constraints for `infer` ([#4830](https://github.com/typescript-eslint/typescript-eslint/issues/4830)) ([8cbbcc3](https://github.com/typescript-eslint/typescript-eslint/commit/8cbbcc3d317779e0dcba15d3835137f38383de34))
+
+
+
+
+
 # [5.25.0](https://github.com/typescript-eslint/typescript-eslint/compare/v5.24.0...v5.25.0) (2022-05-17)
 
 **Note:** Version bump only for package @typescript-eslint/shared-fixtures
diff --git a/packages/shared-fixtures/fixtures/typescript/expressions/instantiation-expression.src.ts b/packages/shared-fixtures/fixtures/typescript/expressions/instantiation-expression.src.ts
new file mode 100644
index 000000000000..6f756d66ee63
--- /dev/null
+++ b/packages/shared-fixtures/fixtures/typescript/expressions/instantiation-expression.src.ts
@@ -0,0 +1,7 @@
+a<b>;
+
+(a<b>)<c>;
+(a<b>)<c>();
+(a<b>)<c>?.();
+(a?.b<c>)<d>();
+new (a<b>)<c>();
diff --git a/packages/shared-fixtures/fixtures/typescript/types/conditional-infer-with-constraint.src.ts b/packages/shared-fixtures/fixtures/typescript/types/conditional-infer-with-constraint.src.ts
new file mode 100644
index 000000000000..36ce0699bb65
--- /dev/null
+++ b/packages/shared-fixtures/fixtures/typescript/types/conditional-infer-with-constraint.src.ts
@@ -0,0 +1,5 @@
+type X3<T> = T extends [infer U extends number] ? MustBeNumber<U> : never;
+type X4<T> = T extends [infer U extends number, infer U extends number] ? MustBeNumber<U> : never;
+type X5<T> = T extends [infer U extends number, infer U] ? MustBeNumber<U> : never;
+type X6<T> = T extends [infer U, infer U extends number] ? MustBeNumber<U> : never;
+type X7<T> = T extends [infer U extends string, infer U extends number] ? U : never;
diff --git a/packages/shared-fixtures/fixtures/typescript/types/optional-variance-in-and-out.src.ts b/packages/shared-fixtures/fixtures/typescript/types/optional-variance-in-and-out.src.ts
new file mode 100644
index 000000000000..ee58a11cfc37
--- /dev/null
+++ b/packages/shared-fixtures/fixtures/typescript/types/optional-variance-in-and-out.src.ts
@@ -0,0 +1 @@
+type Mapper<in T, out U> = (x: T) => U;
diff --git a/packages/shared-fixtures/fixtures/typescript/types/optional-variance-in-out.src.ts b/packages/shared-fixtures/fixtures/typescript/types/optional-variance-in-out.src.ts
new file mode 100644
index 000000000000..1dd6ace1261d
--- /dev/null
+++ b/packages/shared-fixtures/fixtures/typescript/types/optional-variance-in-out.src.ts
@@ -0,0 +1 @@
+type Processor<in out T> = (x: T) => T;
diff --git a/packages/shared-fixtures/fixtures/typescript/types/optional-variance-in.src.ts b/packages/shared-fixtures/fixtures/typescript/types/optional-variance-in.src.ts
new file mode 100644
index 000000000000..3cb911e9c26b
--- /dev/null
+++ b/packages/shared-fixtures/fixtures/typescript/types/optional-variance-in.src.ts
@@ -0,0 +1 @@
+type Consumer<in T> = (x: T) => void;
diff --git a/packages/shared-fixtures/fixtures/typescript/types/optional-variance-out.src.ts b/packages/shared-fixtures/fixtures/typescript/types/optional-variance-out.src.ts
new file mode 100644
index 000000000000..dd9dd2012492
--- /dev/null
+++ b/packages/shared-fixtures/fixtures/typescript/types/optional-variance-out.src.ts
@@ -0,0 +1 @@
+type Provider<out T> = () => T;
diff --git a/packages/shared-fixtures/package.json b/packages/shared-fixtures/package.json
index 3f666f5b95df..d566b750d8a3 100644
--- a/packages/shared-fixtures/package.json
+++ b/packages/shared-fixtures/package.json
@@ -1,5 +1,5 @@
 {
   "name": "@typescript-eslint/shared-fixtures",
-  "version": "5.25.0",
+  "version": "5.26.0",
   "private": true
 }
diff --git a/packages/type-utils/CHANGELOG.md b/packages/type-utils/CHANGELOG.md
index 03410ee17565..a223df579620 100644
--- a/packages/type-utils/CHANGELOG.md
+++ b/packages/type-utils/CHANGELOG.md
@@ -3,6 +3,14 @@
 All notable changes to this project will be documented in this file.
 See [Conventional Commits](https://conventionalcommits.org) for commit guidelines.
 
+# [5.26.0](https://github.com/typescript-eslint/typescript-eslint/compare/v5.25.0...v5.26.0) (2022-05-23)
+
+**Note:** Version bump only for package @typescript-eslint/type-utils
+
+
+
+
+
 # [5.25.0](https://github.com/typescript-eslint/typescript-eslint/compare/v5.24.0...v5.25.0) (2022-05-17)
 
 **Note:** Version bump only for package @typescript-eslint/type-utils
diff --git a/packages/type-utils/jest.config.js b/packages/type-utils/jest.config.js
index 5f1ea3f4bcb0..910991b20cff 100644
--- a/packages/type-utils/jest.config.js
+++ b/packages/type-utils/jest.config.js
@@ -4,5 +4,4 @@
 /** @type {import('@jest/types').Config.InitialOptions} */
 module.exports = {
   ...require('../../jest.config.base.js'),
-  testRegex: './tests/.+\\.test\\.ts$',
 };
diff --git a/packages/type-utils/package.json b/packages/type-utils/package.json
index c13af3b74489..bd660ad19901 100644
--- a/packages/type-utils/package.json
+++ b/packages/type-utils/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@typescript-eslint/type-utils",
-  "version": "5.25.0",
+  "version": "5.26.0",
   "description": "Type utilities for working with TypeScript + ESLint together",
   "keywords": [
     "eslint",
@@ -39,12 +39,12 @@
     "typecheck": "tsc -p tsconfig.json --noEmit"
   },
   "dependencies": {
-    "@typescript-eslint/utils": "5.25.0",
+    "@typescript-eslint/utils": "5.26.0",
     "debug": "^4.3.4",
     "tsutils": "^3.21.0"
   },
   "devDependencies": {
-    "@typescript-eslint/parser": "5.25.0",
+    "@typescript-eslint/parser": "5.26.0",
     "typescript": "*"
   },
   "peerDependencies": {
diff --git a/packages/types/CHANGELOG.md b/packages/types/CHANGELOG.md
index 7cd2e90b53e4..b8a99c2555ed 100644
--- a/packages/types/CHANGELOG.md
+++ b/packages/types/CHANGELOG.md
@@ -3,6 +3,14 @@
 All notable changes to this project will be documented in this file.
 See [Conventional Commits](https://conventionalcommits.org) for commit guidelines.
 
+# [5.26.0](https://github.com/typescript-eslint/typescript-eslint/compare/v5.25.0...v5.26.0) (2022-05-23)
+
+**Note:** Version bump only for package @typescript-eslint/types
+
+
+
+
+
 # [5.25.0](https://github.com/typescript-eslint/typescript-eslint/compare/v5.24.0...v5.25.0) (2022-05-17)
 
 
diff --git a/packages/types/jest.config.js b/packages/types/jest.config.js
index 77fe4d022a95..910991b20cff 100644
--- a/packages/types/jest.config.js
+++ b/packages/types/jest.config.js
@@ -4,5 +4,4 @@
 /** @type {import('@jest/types').Config.InitialOptions} */
 module.exports = {
   ...require('../../jest.config.base.js'),
-  testRegex: ['./tests/.+\\.test\\.ts$'],
 };
diff --git a/packages/types/package.json b/packages/types/package.json
index 2d25da527d1b..e1b20f66ede5 100644
--- a/packages/types/package.json
+++ b/packages/types/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@typescript-eslint/types",
-  "version": "5.25.0",
+  "version": "5.26.0",
   "description": "Types for the TypeScript-ESTree AST spec",
   "keywords": [
     "eslint",
diff --git a/packages/typescript-estree/CHANGELOG.md b/packages/typescript-estree/CHANGELOG.md
index 7508249a5842..b1bd82a8d33d 100644
--- a/packages/typescript-estree/CHANGELOG.md
+++ b/packages/typescript-estree/CHANGELOG.md
@@ -3,6 +3,19 @@
 All notable changes to this project will be documented in this file.
 See [Conventional Commits](https://conventionalcommits.org) for commit guidelines.
 
+# [5.26.0](https://github.com/typescript-eslint/typescript-eslint/compare/v5.25.0...v5.26.0) (2022-05-23)
+
+
+### Features
+
+* [4.7] support instantiation expressions ([#4938](https://github.com/typescript-eslint/typescript-eslint/issues/4938)) ([79fbc77](https://github.com/typescript-eslint/typescript-eslint/commit/79fbc7743ae5dce3190f8168776e0204755390ad))
+* [4.7] support optional variance annotation ([#4831](https://github.com/typescript-eslint/typescript-eslint/issues/4831)) ([7e7b24c](https://github.com/typescript-eslint/typescript-eslint/commit/7e7b24c196e6d968e48f97f46feae5e7027e22d2))
+* **typescript-estree:** `extends` constraints for `infer` ([#4830](https://github.com/typescript-eslint/typescript-eslint/issues/4830)) ([8cbbcc3](https://github.com/typescript-eslint/typescript-eslint/commit/8cbbcc3d317779e0dcba15d3835137f38383de34))
+
+
+
+
+
 # [5.25.0](https://github.com/typescript-eslint/typescript-eslint/compare/v5.24.0...v5.25.0) (2022-05-17)
 
 
diff --git a/packages/typescript-estree/package.json b/packages/typescript-estree/package.json
index fd905d2fb2f0..24366e8f398f 100644
--- a/packages/typescript-estree/package.json
+++ b/packages/typescript-estree/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@typescript-eslint/typescript-estree",
-  "version": "5.25.0",
+  "version": "5.26.0",
   "description": "A parser that converts TypeScript source code into an ESTree compatible form",
   "main": "dist/index.js",
   "types": "dist/index.d.ts",
@@ -41,8 +41,8 @@
     "typecheck": "tsc -p tsconfig.json --noEmit"
   },
   "dependencies": {
-    "@typescript-eslint/types": "5.25.0",
-    "@typescript-eslint/visitor-keys": "5.25.0",
+    "@typescript-eslint/types": "5.26.0",
+    "@typescript-eslint/visitor-keys": "5.26.0",
     "debug": "^4.3.4",
     "globby": "^11.1.0",
     "is-glob": "^4.0.3",
@@ -58,7 +58,7 @@
     "@types/is-glob": "*",
     "@types/semver": "*",
     "@types/tmp": "*",
-    "@typescript-eslint/shared-fixtures": "5.25.0",
+    "@typescript-eslint/shared-fixtures": "5.26.0",
     "glob": "*",
     "jest-specific-snapshot": "*",
     "make-dir": "*",
diff --git a/packages/typescript-estree/src/convert.ts b/packages/typescript-estree/src/convert.ts
index f619a78d5bdc..9e5764296903 100644
--- a/packages/typescript-estree/src/convert.ts
+++ b/packages/typescript-estree/src/convert.ts
@@ -142,7 +142,11 @@ export class Converter {
    * @param result result
    * @returns the ESTreeNode with fixed exports
    */
-  private fixExports<T extends TSESTree.ExportDeclaration>(
+  private fixExports<
+    T extends
+      | TSESTree.DefaultExportDeclarations
+      | TSESTree.NamedExportDeclarations,
+  >(
     node:
       | ts.FunctionDeclaration
       | ts.VariableStatement
@@ -184,9 +188,10 @@ export class Converter {
         const isType =
           result.type === AST_NODE_TYPES.TSInterfaceDeclaration ||
           result.type === AST_NODE_TYPES.TSTypeAliasDeclaration;
-        const isDeclare = result.declare === true;
+        const isDeclare = 'declare' in result && result.declare === true;
         return this.createNode<TSESTree.ExportNamedDeclaration>(node, {
           type: AST_NODE_TYPES.ExportNamedDeclaration,
+          // @ts-expect-error - TODO, narrow the types here
           declaration: result,
           specifiers: [],
           source: null,
@@ -745,10 +750,19 @@ export class Converter {
 
   private assertModuleSpecifier(
     node: ts.ExportDeclaration | ts.ImportDeclaration,
+    allowNull: boolean,
   ): void {
+    if (!allowNull && node.moduleSpecifier == null) {
+      throw createError(
+        this.ast,
+        node.pos,
+        'Module specifier must be a string literal.',
+      );
+    }
+
     if (
       node.moduleSpecifier &&
-      node.moduleSpecifier.kind !== SyntaxKind.StringLiteral
+      node.moduleSpecifier?.kind !== SyntaxKind.StringLiteral
     ) {
       throw createError(
         this.ast,
@@ -964,10 +978,6 @@ export class Converter {
           result.returnType = this.convertTypeAnnotation(node.type, node);
         }
 
-        if (isDeclare) {
-          result.declare = true;
-        }
-
         // Process typeParameters
         if (node.typeParameters) {
           result.typeParameters =
@@ -976,6 +986,10 @@ export class Converter {
             );
         }
 
+        if (isDeclare) {
+          result.declare = true;
+        }
+
         // check for exports
         return this.fixExports(node, result);
       }
@@ -1737,7 +1751,7 @@ export class Converter {
         });
 
       case SyntaxKind.ImportDeclaration: {
-        this.assertModuleSpecifier(node);
+        this.assertModuleSpecifier(node, false);
 
         const result = this.createNode<TSESTree.ImportDeclaration>(node, {
           type: AST_NODE_TYPES.ImportDeclaration,
@@ -1804,8 +1818,8 @@ export class Converter {
       }
 
       case SyntaxKind.ExportDeclaration: {
-        this.assertModuleSpecifier(node);
         if (node.exportClause?.kind === SyntaxKind.NamedExports) {
+          this.assertModuleSpecifier(node, true);
           return this.createNode<TSESTree.ExportNamedDeclaration>(node, {
             type: AST_NODE_TYPES.ExportNamedDeclaration,
             source: this.convertChild(node.moduleSpecifier),
@@ -1817,6 +1831,7 @@ export class Converter {
             assertions: this.convertAssertClasue(node.assertClause),
           });
         } else {
+          this.assertModuleSpecifier(node, false);
           return this.createNode<TSESTree.ExportAllDeclaration>(node, {
             type: AST_NODE_TYPES.ExportAllDeclaration,
             source: this.convertChild(node.moduleSpecifier),
@@ -2342,6 +2357,8 @@ export class Converter {
             ? this.convertType(node.constraint)
             : undefined,
           default: node.default ? this.convertType(node.default) : undefined,
+          in: hasModifier(SyntaxKind.InKeyword, node),
+          out: hasModifier(SyntaxKind.OutKeyword, node),
         });
       }
 
@@ -2574,13 +2591,19 @@ export class Converter {
       }
 
       case SyntaxKind.ExpressionWithTypeArguments: {
+        const parentKind = parent.kind;
+        const type =
+          parentKind === SyntaxKind.InterfaceDeclaration
+            ? AST_NODE_TYPES.TSInterfaceHeritage
+            : parentKind === SyntaxKind.HeritageClause
+            ? AST_NODE_TYPES.TSClassImplements
+            : AST_NODE_TYPES.TSInstantiationExpression;
         const result = this.createNode<
-          TSESTree.TSInterfaceHeritage | TSESTree.TSClassImplements
+          | TSESTree.TSInterfaceHeritage
+          | TSESTree.TSClassImplements
+          | TSESTree.TSInstantiationExpression
         >(node, {
-          type:
-            parent && parent.kind === SyntaxKind.InterfaceDeclaration
-              ? AST_NODE_TYPES.TSInterfaceHeritage
-              : AST_NODE_TYPES.TSClassImplements,
+          type,
           expression: this.convertChild(node.expression),
         });
 
diff --git a/packages/typescript-estree/src/ts-estree/estree-to-ts-node-types.ts b/packages/typescript-estree/src/ts-estree/estree-to-ts-node-types.ts
index 0398d1991c20..666909b5a714 100644
--- a/packages/typescript-estree/src/ts-estree/estree-to-ts-node-types.ts
+++ b/packages/typescript-estree/src/ts-estree/estree-to-ts-node-types.ts
@@ -180,6 +180,7 @@ export interface EstreeToTsNodeTypes {
   [AST_NODE_TYPES.TSInterfaceBody]: ts.InterfaceDeclaration;
   [AST_NODE_TYPES.TSInterfaceHeritage]: ts.ExpressionWithTypeArguments;
   [AST_NODE_TYPES.TSIntersectionType]: ts.IntersectionTypeNode;
+  [AST_NODE_TYPES.TSInstantiationExpression]: ts.ExpressionWithTypeArguments;
   [AST_NODE_TYPES.TSLiteralType]: ts.LiteralTypeNode;
   [AST_NODE_TYPES.TSMappedType]: ts.MappedTypeNode;
   [AST_NODE_TYPES.TSMethodSignature]:
diff --git a/packages/typescript-estree/tests/ast-alignment/fixtures-to-test.ts b/packages/typescript-estree/tests/ast-alignment/fixtures-to-test.ts
index 5f44161557cf..50981c203633 100644
--- a/packages/typescript-estree/tests/ast-alignment/fixtures-to-test.ts
+++ b/packages/typescript-estree/tests/ast-alignment/fixtures-to-test.ts
@@ -453,6 +453,13 @@ tester.addFixturePatternConfig('typescript/decorators/property-decorators', {
 
 tester.addFixturePatternConfig('typescript/expressions', {
   fileType: 'ts',
+  ignore: [
+    /**
+     * [BABEL ERRORED, BUT TS-ESTREE DID NOT]
+     * Babel doesn't support TS 4.7 new features yet.
+     */
+    'instantiation-expression',
+  ],
 });
 
 tester.addFixturePatternConfig('typescript/errorRecovery', {
@@ -484,6 +491,19 @@ tester.addFixturePatternConfig('typescript/types', {
     'template-literal-type-2',
     'template-literal-type-3',
     'template-literal-type-4',
+    /**
+     * [BABEL ERRORED, BUT TS-ESTREE DID NOT]
+     * Babel doesn't support TS 4.7 new feature yet.
+     */
+    'conditional-infer-with-constraint',
+    /**
+     * [BABEL ERRORED, BUT TS-ESTREE DID NOT]
+     * Babel doesn't support TS 4.7 new features yet.
+     */
+    'optional-variance-in',
+    'optional-variance-out',
+    'optional-variance-in-out',
+    'optional-variance-in-and-out',
   ],
 });
 
diff --git a/packages/typescript-estree/tests/ast-alignment/utils.ts b/packages/typescript-estree/tests/ast-alignment/utils.ts
index ece4ab9e5112..01283b2a3f01 100644
--- a/packages/typescript-estree/tests/ast-alignment/utils.ts
+++ b/packages/typescript-estree/tests/ast-alignment/utils.ts
@@ -150,6 +150,13 @@ export function preprocessBabylonAST(ast: File): any {
             type: AST_NODE_TYPES.Identifier,
           };
         }
+        // Babel does not support TS 4.7 optional variance yet.
+        if (!node.in) {
+          node.in = false;
+        }
+        if (!node.out) {
+          node.out = false;
+        }
       },
       MethodDefinition(node) {
         /**
diff --git a/packages/typescript-estree/tests/lib/__snapshots__/convert.test.ts.snap b/packages/typescript-estree/tests/lib/__snapshots__/convert.test.ts.snap
index 0ea5f89cdcdb..0f40740978e1 100644
--- a/packages/typescript-estree/tests/lib/__snapshots__/convert.test.ts.snap
+++ b/packages/typescript-estree/tests/lib/__snapshots__/convert.test.ts.snap
@@ -475,6 +475,7 @@ Object {
       Object {
         "constraint": undefined,
         "default": undefined,
+        "in": false,
         "loc": Object {
           "end": Object {
             "column": 11,
@@ -503,6 +504,7 @@ Object {
           ],
           "type": "Identifier",
         },
+        "out": false,
         "range": Array [
           10,
           11,
diff --git a/packages/typescript-estree/tests/lib/__snapshots__/semantic-diagnostics-enabled.test.ts.snap b/packages/typescript-estree/tests/lib/__snapshots__/semantic-diagnostics-enabled.test.ts.snap
index 03f030ad731e..12e8316d7b6f 100644
--- a/packages/typescript-estree/tests/lib/__snapshots__/semantic-diagnostics-enabled.test.ts.snap
+++ b/packages/typescript-estree/tests/lib/__snapshots__/semantic-diagnostics-enabled.test.ts.snap
@@ -2640,6 +2640,8 @@ TSError {
 
 exports[`Parse all fixtures with "errorOnTypeScriptSyntacticAndSemanticIssues" enabled fixtures/typescript/expressions/call-expression-type-arguments.src 1`] = `"TEST OUTPUT: No semantic or syntactic issues found"`;
 
+exports[`Parse all fixtures with "errorOnTypeScriptSyntacticAndSemanticIssues" enabled fixtures/typescript/expressions/instantiation-expression.src 1`] = `"TEST OUTPUT: No semantic or syntactic issues found"`;
+
 exports[`Parse all fixtures with "errorOnTypeScriptSyntacticAndSemanticIssues" enabled fixtures/typescript/expressions/new-expression-type-arguments.src 1`] = `"TEST OUTPUT: No semantic or syntactic issues found"`;
 
 exports[`Parse all fixtures with "errorOnTypeScriptSyntacticAndSemanticIssues" enabled fixtures/typescript/expressions/optional-call-expression-type-arguments.src 1`] = `"TEST OUTPUT: No semantic or syntactic issues found"`;
@@ -2668,6 +2670,8 @@ exports[`Parse all fixtures with "errorOnTypeScriptSyntacticAndSemanticIssues" e
 
 exports[`Parse all fixtures with "errorOnTypeScriptSyntacticAndSemanticIssues" enabled fixtures/typescript/types/conditional-infer-simple.src 1`] = `"TEST OUTPUT: No semantic or syntactic issues found"`;
 
+exports[`Parse all fixtures with "errorOnTypeScriptSyntacticAndSemanticIssues" enabled fixtures/typescript/types/conditional-infer-with-constraint.src 1`] = `"TEST OUTPUT: No semantic or syntactic issues found"`;
+
 exports[`Parse all fixtures with "errorOnTypeScriptSyntacticAndSemanticIssues" enabled fixtures/typescript/types/conditional-with-null.src 1`] = `"TEST OUTPUT: No semantic or syntactic issues found"`;
 
 exports[`Parse all fixtures with "errorOnTypeScriptSyntacticAndSemanticIssues" enabled fixtures/typescript/types/constructor.src 1`] = `"TEST OUTPUT: No semantic or syntactic issues found"`;
@@ -2730,6 +2734,14 @@ exports[`Parse all fixtures with "errorOnTypeScriptSyntacticAndSemanticIssues" e
 
 exports[`Parse all fixtures with "errorOnTypeScriptSyntacticAndSemanticIssues" enabled fixtures/typescript/types/object-literal-type-with-accessors.src 1`] = `"TEST OUTPUT: No semantic or syntactic issues found"`;
 
+exports[`Parse all fixtures with "errorOnTypeScriptSyntacticAndSemanticIssues" enabled fixtures/typescript/types/optional-variance-in.src 1`] = `"TEST OUTPUT: No semantic or syntactic issues found"`;
+
+exports[`Parse all fixtures with "errorOnTypeScriptSyntacticAndSemanticIssues" enabled fixtures/typescript/types/optional-variance-in-and-out.src 1`] = `"TEST OUTPUT: No semantic or syntactic issues found"`;
+
+exports[`Parse all fixtures with "errorOnTypeScriptSyntacticAndSemanticIssues" enabled fixtures/typescript/types/optional-variance-in-out.src 1`] = `"TEST OUTPUT: No semantic or syntactic issues found"`;
+
+exports[`Parse all fixtures with "errorOnTypeScriptSyntacticAndSemanticIssues" enabled fixtures/typescript/types/optional-variance-out.src 1`] = `"TEST OUTPUT: No semantic or syntactic issues found"`;
+
 exports[`Parse all fixtures with "errorOnTypeScriptSyntacticAndSemanticIssues" enabled fixtures/typescript/types/parenthesized-type.src 1`] = `"TEST OUTPUT: No semantic or syntactic issues found"`;
 
 exports[`Parse all fixtures with "errorOnTypeScriptSyntacticAndSemanticIssues" enabled fixtures/typescript/types/reference.src 1`] = `"TEST OUTPUT: No semantic or syntactic issues found"`;
diff --git a/packages/typescript-estree/tests/snapshots/typescript/babylon-convergence/type-parameter-whitespace-loc.src.ts.shot b/packages/typescript-estree/tests/snapshots/typescript/babylon-convergence/type-parameter-whitespace-loc.src.ts.shot
index 84a0faacccaf..a32b6821f9e6 100644
--- a/packages/typescript-estree/tests/snapshots/typescript/babylon-convergence/type-parameter-whitespace-loc.src.ts.shot
+++ b/packages/typescript-estree/tests/snapshots/typescript/babylon-convergence/type-parameter-whitespace-loc.src.ts.shot
@@ -74,6 +74,7 @@ Object {
           Object {
             "constraint": undefined,
             "default": undefined,
+            "in": false,
             "loc": Object {
               "end": Object {
                 "column": 14,
@@ -102,6 +103,7 @@ Object {
               ],
               "type": "Identifier",
             },
+            "out": false,
             "range": Array [
               13,
               14,
diff --git a/packages/typescript-estree/tests/snapshots/typescript/babylon-convergence/type-parameters.src.ts.shot b/packages/typescript-estree/tests/snapshots/typescript/babylon-convergence/type-parameters.src.ts.shot
index 245b52dc08a6..bd4752cee3b3 100644
--- a/packages/typescript-estree/tests/snapshots/typescript/babylon-convergence/type-parameters.src.ts.shot
+++ b/packages/typescript-estree/tests/snapshots/typescript/babylon-convergence/type-parameters.src.ts.shot
@@ -106,6 +106,7 @@ Object {
               ],
               "type": "TSObjectKeyword",
             },
+            "in": false,
             "loc": Object {
               "end": Object {
                 "column": 36,
@@ -134,6 +135,7 @@ Object {
               ],
               "type": "Identifier",
             },
+            "out": false,
             "range": Array [
               11,
               36,
diff --git a/packages/typescript-estree/tests/snapshots/typescript/basics/arrow-function-with-type-parameters.src.ts.shot b/packages/typescript-estree/tests/snapshots/typescript/basics/arrow-function-with-type-parameters.src.ts.shot
index 126d82a31154..b233dae579ec 100644
--- a/packages/typescript-estree/tests/snapshots/typescript/basics/arrow-function-with-type-parameters.src.ts.shot
+++ b/packages/typescript-estree/tests/snapshots/typescript/basics/arrow-function-with-type-parameters.src.ts.shot
@@ -219,6 +219,7 @@ Object {
             Object {
               "constraint": undefined,
               "default": undefined,
+              "in": false,
               "loc": Object {
                 "end": Object {
                   "column": 2,
@@ -247,6 +248,7 @@ Object {
                 ],
                 "type": "Identifier",
               },
+              "out": false,
               "range": Array [
                 1,
                 2,
diff --git a/packages/typescript-estree/tests/snapshots/typescript/basics/call-signatures-with-generics.src.ts.shot b/packages/typescript-estree/tests/snapshots/typescript/basics/call-signatures-with-generics.src.ts.shot
index 84bc3e241e60..8ec8827246f1 100644
--- a/packages/typescript-estree/tests/snapshots/typescript/basics/call-signatures-with-generics.src.ts.shot
+++ b/packages/typescript-estree/tests/snapshots/typescript/basics/call-signatures-with-generics.src.ts.shot
@@ -168,6 +168,7 @@ Object {
                 Object {
                   "constraint": undefined,
                   "default": undefined,
+                  "in": false,
                   "loc": Object {
                     "end": Object {
                       "column": 4,
@@ -196,6 +197,7 @@ Object {
                     ],
                     "type": "Identifier",
                   },
+                  "out": false,
                   "range": Array [
                     16,
                     17,
@@ -329,6 +331,7 @@ Object {
                 Object {
                   "constraint": undefined,
                   "default": undefined,
+                  "in": false,
                   "loc": Object {
                     "end": Object {
                       "column": 7,
@@ -357,6 +360,7 @@ Object {
                     ],
                     "type": "Identifier",
                   },
+                  "out": false,
                   "range": Array [
                     44,
                     45,
diff --git a/packages/typescript-estree/tests/snapshots/typescript/basics/class-with-constructor-and-type-parameters.src.ts.shot b/packages/typescript-estree/tests/snapshots/typescript/basics/class-with-constructor-and-type-parameters.src.ts.shot
index 56353693fd68..fc9e41e1cce8 100644
--- a/packages/typescript-estree/tests/snapshots/typescript/basics/class-with-constructor-and-type-parameters.src.ts.shot
+++ b/packages/typescript-estree/tests/snapshots/typescript/basics/class-with-constructor-and-type-parameters.src.ts.shot
@@ -98,6 +98,7 @@ Object {
                   Object {
                     "constraint": undefined,
                     "default": undefined,
+                    "in": false,
                     "loc": Object {
                       "end": Object {
                         "column": 15,
@@ -126,6 +127,7 @@ Object {
                       ],
                       "type": "Identifier",
                     },
+                    "out": false,
                     "range": Array [
                       24,
                       25,
@@ -234,6 +236,7 @@ Object {
                   Object {
                     "constraint": undefined,
                     "default": undefined,
+                    "in": false,
                     "loc": Object {
                       "end": Object {
                         "column": 19,
@@ -262,6 +265,7 @@ Object {
                       ],
                       "type": "Identifier",
                     },
+                    "out": false,
                     "range": Array [
                       52,
                       53,
diff --git a/packages/typescript-estree/tests/snapshots/typescript/basics/class-with-extends-generic-multiple.src.ts.shot b/packages/typescript-estree/tests/snapshots/typescript/basics/class-with-extends-generic-multiple.src.ts.shot
index bc3a09258d02..4b1632815042 100644
--- a/packages/typescript-estree/tests/snapshots/typescript/basics/class-with-extends-generic-multiple.src.ts.shot
+++ b/packages/typescript-estree/tests/snapshots/typescript/basics/class-with-extends-generic-multiple.src.ts.shot
@@ -214,6 +214,7 @@ Object {
               "typeParameters": undefined,
             },
             "default": undefined,
+            "in": false,
             "loc": Object {
               "end": Object {
                 "column": 21,
@@ -242,6 +243,7 @@ Object {
               ],
               "type": "Identifier",
             },
+            "out": false,
             "range": Array [
               10,
               21,
diff --git a/packages/typescript-estree/tests/snapshots/typescript/basics/class-with-extends-generic.src.ts.shot b/packages/typescript-estree/tests/snapshots/typescript/basics/class-with-extends-generic.src.ts.shot
index fac393614970..1b34e17f7ebc 100644
--- a/packages/typescript-estree/tests/snapshots/typescript/basics/class-with-extends-generic.src.ts.shot
+++ b/packages/typescript-estree/tests/snapshots/typescript/basics/class-with-extends-generic.src.ts.shot
@@ -143,6 +143,7 @@ Object {
           Object {
             "constraint": undefined,
             "default": undefined,
+            "in": false,
             "loc": Object {
               "end": Object {
                 "column": 11,
@@ -171,6 +172,7 @@ Object {
               ],
               "type": "Identifier",
             },
+            "out": false,
             "range": Array [
               10,
               11,
diff --git a/packages/typescript-estree/tests/snapshots/typescript/basics/class-with-generic-method-default.src.ts.shot b/packages/typescript-estree/tests/snapshots/typescript/basics/class-with-generic-method-default.src.ts.shot
index 517d5dd3e62a..d648e1c98cf4 100644
--- a/packages/typescript-estree/tests/snapshots/typescript/basics/class-with-generic-method-default.src.ts.shot
+++ b/packages/typescript-estree/tests/snapshots/typescript/basics/class-with-generic-method-default.src.ts.shot
@@ -133,6 +133,7 @@ Object {
                       },
                       "typeParameters": undefined,
                     },
+                    "in": false,
                     "loc": Object {
                       "end": Object {
                         "column": 16,
@@ -161,6 +162,7 @@ Object {
                       ],
                       "type": "Identifier",
                     },
+                    "out": false,
                     "range": Array [
                       21,
                       28,
diff --git a/packages/typescript-estree/tests/snapshots/typescript/basics/class-with-generic-method.src.ts.shot b/packages/typescript-estree/tests/snapshots/typescript/basics/class-with-generic-method.src.ts.shot
index 504612e7858d..f00ade847e86 100644
--- a/packages/typescript-estree/tests/snapshots/typescript/basics/class-with-generic-method.src.ts.shot
+++ b/packages/typescript-estree/tests/snapshots/typescript/basics/class-with-generic-method.src.ts.shot
@@ -98,6 +98,7 @@ Object {
                   Object {
                     "constraint": undefined,
                     "default": undefined,
+                    "in": false,
                     "loc": Object {
                       "end": Object {
                         "column": 10,
@@ -126,6 +127,7 @@ Object {
                       ],
                       "type": "Identifier",
                     },
+                    "out": false,
                     "range": Array [
                       21,
                       22,
diff --git a/packages/typescript-estree/tests/snapshots/typescript/basics/class-with-method.src.ts.shot b/packages/typescript-estree/tests/snapshots/typescript/basics/class-with-method.src.ts.shot
index 84f1c8825bcb..7519442ea6e9 100644
--- a/packages/typescript-estree/tests/snapshots/typescript/basics/class-with-method.src.ts.shot
+++ b/packages/typescript-estree/tests/snapshots/typescript/basics/class-with-method.src.ts.shot
@@ -211,6 +211,7 @@ Object {
                   Object {
                     "constraint": undefined,
                     "default": undefined,
+                    "in": false,
                     "loc": Object {
                       "end": Object {
                         "column": 7,
@@ -239,6 +240,7 @@ Object {
                       ],
                       "type": "Identifier",
                     },
+                    "out": false,
                     "range": Array [
                       36,
                       37,
diff --git a/packages/typescript-estree/tests/snapshots/typescript/basics/class-with-mixin-reference.src.ts.shot b/packages/typescript-estree/tests/snapshots/typescript/basics/class-with-mixin-reference.src.ts.shot
index e9b4d70e8378..47dd1de2f0d9 100644
--- a/packages/typescript-estree/tests/snapshots/typescript/basics/class-with-mixin-reference.src.ts.shot
+++ b/packages/typescript-estree/tests/snapshots/typescript/basics/class-with-mixin-reference.src.ts.shot
@@ -235,6 +235,7 @@ Object {
               },
             },
             "default": undefined,
+            "in": false,
             "loc": Object {
               "end": Object {
                 "column": 35,
@@ -263,6 +264,7 @@ Object {
               ],
               "type": "Identifier",
             },
+            "out": false,
             "range": Array [
               11,
               35,
diff --git a/packages/typescript-estree/tests/snapshots/typescript/basics/class-with-mixin.src.ts.shot b/packages/typescript-estree/tests/snapshots/typescript/basics/class-with-mixin.src.ts.shot
index 7ea53067001e..8a9917336111 100644
--- a/packages/typescript-estree/tests/snapshots/typescript/basics/class-with-mixin.src.ts.shot
+++ b/packages/typescript-estree/tests/snapshots/typescript/basics/class-with-mixin.src.ts.shot
@@ -289,6 +289,7 @@ Object {
               },
             },
             "default": undefined,
+            "in": false,
             "loc": Object {
               "end": Object {
                 "column": 36,
@@ -317,6 +318,7 @@ Object {
               ],
               "type": "Identifier",
             },
+            "out": false,
             "range": Array [
               11,
               36,
@@ -828,6 +830,7 @@ Object {
           Object {
             "constraint": undefined,
             "default": undefined,
+            "in": false,
             "loc": Object {
               "end": Object {
                 "column": 18,
@@ -856,6 +859,7 @@ Object {
               ],
               "type": "Identifier",
             },
+            "out": false,
             "range": Array [
               175,
               176,
diff --git a/packages/typescript-estree/tests/snapshots/typescript/basics/class-with-two-methods-computed-constructor.src.ts.shot b/packages/typescript-estree/tests/snapshots/typescript/basics/class-with-two-methods-computed-constructor.src.ts.shot
index abf1f5816b2e..f119f99cc7c6 100644
--- a/packages/typescript-estree/tests/snapshots/typescript/basics/class-with-two-methods-computed-constructor.src.ts.shot
+++ b/packages/typescript-estree/tests/snapshots/typescript/basics/class-with-two-methods-computed-constructor.src.ts.shot
@@ -133,6 +133,7 @@ Object {
                   Object {
                     "constraint": undefined,
                     "default": undefined,
+                    "in": false,
                     "loc": Object {
                       "end": Object {
                         "column": 17,
@@ -161,6 +162,7 @@ Object {
                       ],
                       "type": "Identifier",
                     },
+                    "out": false,
                     "range": Array [
                       26,
                       27,
@@ -303,6 +305,7 @@ Object {
                   Object {
                     "constraint": undefined,
                     "default": undefined,
+                    "in": false,
                     "loc": Object {
                       "end": Object {
                         "column": 19,
@@ -331,6 +334,7 @@ Object {
                       ],
                       "type": "Identifier",
                     },
+                    "out": false,
                     "range": Array [
                       64,
                       65,
diff --git a/packages/typescript-estree/tests/snapshots/typescript/basics/class-with-type-parameter-default.src.ts.shot b/packages/typescript-estree/tests/snapshots/typescript/basics/class-with-type-parameter-default.src.ts.shot
index 7f1f690528fa..b062afebf385 100644
--- a/packages/typescript-estree/tests/snapshots/typescript/basics/class-with-type-parameter-default.src.ts.shot
+++ b/packages/typescript-estree/tests/snapshots/typescript/basics/class-with-type-parameter-default.src.ts.shot
@@ -106,6 +106,7 @@ Object {
               },
               "typeParameters": undefined,
             },
+            "in": false,
             "loc": Object {
               "end": Object {
                 "column": 17,
@@ -134,6 +135,7 @@ Object {
               ],
               "type": "Identifier",
             },
+            "out": false,
             "range": Array [
               10,
               17,
diff --git a/packages/typescript-estree/tests/snapshots/typescript/basics/class-with-type-parameter-underscore.src.ts.shot b/packages/typescript-estree/tests/snapshots/typescript/basics/class-with-type-parameter-underscore.src.ts.shot
index d069b3552b37..f11826fd1047 100644
--- a/packages/typescript-estree/tests/snapshots/typescript/basics/class-with-type-parameter-underscore.src.ts.shot
+++ b/packages/typescript-estree/tests/snapshots/typescript/basics/class-with-type-parameter-underscore.src.ts.shot
@@ -71,6 +71,7 @@ Object {
           Object {
             "constraint": undefined,
             "default": undefined,
+            "in": false,
             "loc": Object {
               "end": Object {
                 "column": 11,
@@ -99,6 +100,7 @@ Object {
               ],
               "type": "Identifier",
             },
+            "out": false,
             "range": Array [
               8,
               11,
diff --git a/packages/typescript-estree/tests/snapshots/typescript/basics/class-with-type-parameter.src.ts.shot b/packages/typescript-estree/tests/snapshots/typescript/basics/class-with-type-parameter.src.ts.shot
index 3e52dcb8d33f..8403e95ce8cb 100644
--- a/packages/typescript-estree/tests/snapshots/typescript/basics/class-with-type-parameter.src.ts.shot
+++ b/packages/typescript-estree/tests/snapshots/typescript/basics/class-with-type-parameter.src.ts.shot
@@ -71,6 +71,7 @@ Object {
           Object {
             "constraint": undefined,
             "default": undefined,
+            "in": false,
             "loc": Object {
               "end": Object {
                 "column": 11,
@@ -99,6 +100,7 @@ Object {
               ],
               "type": "Identifier",
             },
+            "out": false,
             "range": Array [
               10,
               11,
diff --git a/packages/typescript-estree/tests/snapshots/typescript/basics/export-default-class-with-generic.src.ts.shot b/packages/typescript-estree/tests/snapshots/typescript/basics/export-default-class-with-generic.src.ts.shot
index b2054c9f8be7..b8c81c94fc25 100644
--- a/packages/typescript-estree/tests/snapshots/typescript/basics/export-default-class-with-generic.src.ts.shot
+++ b/packages/typescript-estree/tests/snapshots/typescript/basics/export-default-class-with-generic.src.ts.shot
@@ -55,6 +55,7 @@ Object {
             Object {
               "constraint": undefined,
               "default": undefined,
+              "in": false,
               "loc": Object {
                 "end": Object {
                   "column": 22,
@@ -83,6 +84,7 @@ Object {
                 ],
                 "type": "Identifier",
               },
+              "out": false,
               "range": Array [
                 21,
                 22,
diff --git a/packages/typescript-estree/tests/snapshots/typescript/basics/export-default-class-with-multiple-generics.src.ts.shot b/packages/typescript-estree/tests/snapshots/typescript/basics/export-default-class-with-multiple-generics.src.ts.shot
index ad9d453a4915..5c8f0f1bd137 100644
--- a/packages/typescript-estree/tests/snapshots/typescript/basics/export-default-class-with-multiple-generics.src.ts.shot
+++ b/packages/typescript-estree/tests/snapshots/typescript/basics/export-default-class-with-multiple-generics.src.ts.shot
@@ -55,6 +55,7 @@ Object {
             Object {
               "constraint": undefined,
               "default": undefined,
+              "in": false,
               "loc": Object {
                 "end": Object {
                   "column": 22,
@@ -83,6 +84,7 @@ Object {
                 ],
                 "type": "Identifier",
               },
+              "out": false,
               "range": Array [
                 21,
                 22,
@@ -92,6 +94,7 @@ Object {
             Object {
               "constraint": undefined,
               "default": undefined,
+              "in": false,
               "loc": Object {
                 "end": Object {
                   "column": 25,
@@ -120,6 +123,7 @@ Object {
                 ],
                 "type": "Identifier",
               },
+              "out": false,
               "range": Array [
                 24,
                 25,
diff --git a/packages/typescript-estree/tests/snapshots/typescript/basics/export-named-class-with-generic.src.ts.shot b/packages/typescript-estree/tests/snapshots/typescript/basics/export-named-class-with-generic.src.ts.shot
index 4a6484753839..150f857526dd 100644
--- a/packages/typescript-estree/tests/snapshots/typescript/basics/export-named-class-with-generic.src.ts.shot
+++ b/packages/typescript-estree/tests/snapshots/typescript/basics/export-named-class-with-generic.src.ts.shot
@@ -73,6 +73,7 @@ Object {
             Object {
               "constraint": undefined,
               "default": undefined,
+              "in": false,
               "loc": Object {
                 "end": Object {
                   "column": 18,
@@ -101,6 +102,7 @@ Object {
                 ],
                 "type": "Identifier",
               },
+              "out": false,
               "range": Array [
                 17,
                 18,
diff --git a/packages/typescript-estree/tests/snapshots/typescript/basics/export-named-class-with-multiple-generics.src.ts.shot b/packages/typescript-estree/tests/snapshots/typescript/basics/export-named-class-with-multiple-generics.src.ts.shot
index 988daf8a174e..74f2566093d5 100644
--- a/packages/typescript-estree/tests/snapshots/typescript/basics/export-named-class-with-multiple-generics.src.ts.shot
+++ b/packages/typescript-estree/tests/snapshots/typescript/basics/export-named-class-with-multiple-generics.src.ts.shot
@@ -73,6 +73,7 @@ Object {
             Object {
               "constraint": undefined,
               "default": undefined,
+              "in": false,
               "loc": Object {
                 "end": Object {
                   "column": 18,
@@ -101,6 +102,7 @@ Object {
                 ],
                 "type": "Identifier",
               },
+              "out": false,
               "range": Array [
                 17,
                 18,
@@ -110,6 +112,7 @@ Object {
             Object {
               "constraint": undefined,
               "default": undefined,
+              "in": false,
               "loc": Object {
                 "end": Object {
                   "column": 21,
@@ -138,6 +141,7 @@ Object {
                 ],
                 "type": "Identifier",
               },
+              "out": false,
               "range": Array [
                 20,
                 21,
diff --git a/packages/typescript-estree/tests/snapshots/typescript/basics/function-anonymus-with-type-parameters.src.ts.shot b/packages/typescript-estree/tests/snapshots/typescript/basics/function-anonymus-with-type-parameters.src.ts.shot
index 018d4d725523..9945853dea09 100644
--- a/packages/typescript-estree/tests/snapshots/typescript/basics/function-anonymus-with-type-parameters.src.ts.shot
+++ b/packages/typescript-estree/tests/snapshots/typescript/basics/function-anonymus-with-type-parameters.src.ts.shot
@@ -167,6 +167,7 @@ Object {
                 Object {
                   "constraint": undefined,
                   "default": undefined,
+                  "in": false,
                   "loc": Object {
                     "end": Object {
                       "column": 21,
@@ -195,6 +196,7 @@ Object {
                     ],
                     "type": "Identifier",
                   },
+                  "out": false,
                   "range": Array [
                     20,
                     21,
diff --git a/packages/typescript-estree/tests/snapshots/typescript/basics/function-with-type-parameters-that-have-comments.src.ts.shot b/packages/typescript-estree/tests/snapshots/typescript/basics/function-with-type-parameters-that-have-comments.src.ts.shot
index b626f8aa8037..0bd43c2697c4 100644
--- a/packages/typescript-estree/tests/snapshots/typescript/basics/function-with-type-parameters-that-have-comments.src.ts.shot
+++ b/packages/typescript-estree/tests/snapshots/typescript/basics/function-with-type-parameters-that-have-comments.src.ts.shot
@@ -74,6 +74,7 @@ Object {
           Object {
             "constraint": undefined,
             "default": undefined,
+            "in": false,
             "loc": Object {
               "end": Object {
                 "column": 29,
@@ -102,6 +103,7 @@ Object {
               ],
               "type": "Identifier",
             },
+            "out": false,
             "range": Array [
               28,
               29,
diff --git a/packages/typescript-estree/tests/snapshots/typescript/basics/function-with-type-parameters-with-constraint.src.ts.shot b/packages/typescript-estree/tests/snapshots/typescript/basics/function-with-type-parameters-with-constraint.src.ts.shot
index a3ae99a13775..114fd02b9e62 100644
--- a/packages/typescript-estree/tests/snapshots/typescript/basics/function-with-type-parameters-with-constraint.src.ts.shot
+++ b/packages/typescript-estree/tests/snapshots/typescript/basics/function-with-type-parameters-with-constraint.src.ts.shot
@@ -252,6 +252,7 @@ Object {
               "type": "TSTypeLiteral",
             },
             "default": undefined,
+            "in": false,
             "loc": Object {
               "end": Object {
                 "column": 23,
@@ -280,6 +281,7 @@ Object {
               ],
               "type": "Identifier",
             },
+            "out": false,
             "range": Array [
               11,
               23,
diff --git a/packages/typescript-estree/tests/snapshots/typescript/basics/function-with-type-parameters.src.ts.shot b/packages/typescript-estree/tests/snapshots/typescript/basics/function-with-type-parameters.src.ts.shot
index d65c9203b652..defa0485d9e3 100644
--- a/packages/typescript-estree/tests/snapshots/typescript/basics/function-with-type-parameters.src.ts.shot
+++ b/packages/typescript-estree/tests/snapshots/typescript/basics/function-with-type-parameters.src.ts.shot
@@ -235,6 +235,7 @@ Object {
           Object {
             "constraint": undefined,
             "default": undefined,
+            "in": false,
             "loc": Object {
               "end": Object {
                 "column": 12,
@@ -263,6 +264,7 @@ Object {
               ],
               "type": "Identifier",
             },
+            "out": false,
             "range": Array [
               11,
               12,
diff --git a/packages/typescript-estree/tests/snapshots/typescript/basics/instantiation-expression.src.ts.shot b/packages/typescript-estree/tests/snapshots/typescript/basics/instantiation-expression.src.ts.shot
new file mode 100644
index 000000000000..92bc144ccc0f
--- /dev/null
+++ b/packages/typescript-estree/tests/snapshots/typescript/basics/instantiation-expression.src.ts.shot
@@ -0,0 +1,2330 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`typescript basics instantiation-expression.src 1`] = `
+Object {
+  "body": Array [
+    Object {
+      "expression": Object {
+        "expression": Object {
+          "loc": Object {
+            "end": Object {
+              "column": 1,
+              "line": 1,
+            },
+            "start": Object {
+              "column": 0,
+              "line": 1,
+            },
+          },
+          "name": "a",
+          "range": Array [
+            0,
+            1,
+          ],
+          "type": "Identifier",
+        },
+        "loc": Object {
+          "end": Object {
+            "column": 4,
+            "line": 1,
+          },
+          "start": Object {
+            "column": 0,
+            "line": 1,
+          },
+        },
+        "range": Array [
+          0,
+          4,
+        ],
+        "type": "TSInstantiationExpression",
+        "typeParameters": Object {
+          "loc": Object {
+            "end": Object {
+              "column": 4,
+              "line": 1,
+            },
+            "start": Object {
+              "column": 1,
+              "line": 1,
+            },
+          },
+          "params": Array [
+            Object {
+              "loc": Object {
+                "end": Object {
+                  "column": 3,
+                  "line": 1,
+                },
+                "start": Object {
+                  "column": 2,
+                  "line": 1,
+                },
+              },
+              "range": Array [
+                2,
+                3,
+              ],
+              "type": "TSTypeReference",
+              "typeName": Object {
+                "loc": Object {
+                  "end": Object {
+                    "column": 3,
+                    "line": 1,
+                  },
+                  "start": Object {
+                    "column": 2,
+                    "line": 1,
+                  },
+                },
+                "name": "b",
+                "range": Array [
+                  2,
+                  3,
+                ],
+                "type": "Identifier",
+              },
+              "typeParameters": undefined,
+            },
+          ],
+          "range": Array [
+            1,
+            4,
+          ],
+          "type": "TSTypeParameterInstantiation",
+        },
+      },
+      "loc": Object {
+        "end": Object {
+          "column": 5,
+          "line": 1,
+        },
+        "start": Object {
+          "column": 0,
+          "line": 1,
+        },
+      },
+      "range": Array [
+        0,
+        5,
+      ],
+      "type": "ExpressionStatement",
+    },
+    Object {
+      "expression": Object {
+        "expression": Object {
+          "expression": Object {
+            "loc": Object {
+              "end": Object {
+                "column": 2,
+                "line": 3,
+              },
+              "start": Object {
+                "column": 1,
+                "line": 3,
+              },
+            },
+            "name": "a",
+            "range": Array [
+              8,
+              9,
+            ],
+            "type": "Identifier",
+          },
+          "loc": Object {
+            "end": Object {
+              "column": 5,
+              "line": 3,
+            },
+            "start": Object {
+              "column": 1,
+              "line": 3,
+            },
+          },
+          "range": Array [
+            8,
+            12,
+          ],
+          "type": "TSInstantiationExpression",
+          "typeParameters": Object {
+            "loc": Object {
+              "end": Object {
+                "column": 5,
+                "line": 3,
+              },
+              "start": Object {
+                "column": 2,
+                "line": 3,
+              },
+            },
+            "params": Array [
+              Object {
+                "loc": Object {
+                  "end": Object {
+                    "column": 4,
+                    "line": 3,
+                  },
+                  "start": Object {
+                    "column": 3,
+                    "line": 3,
+                  },
+                },
+                "range": Array [
+                  10,
+                  11,
+                ],
+                "type": "TSTypeReference",
+                "typeName": Object {
+                  "loc": Object {
+                    "end": Object {
+                      "column": 4,
+                      "line": 3,
+                    },
+                    "start": Object {
+                      "column": 3,
+                      "line": 3,
+                    },
+                  },
+                  "name": "b",
+                  "range": Array [
+                    10,
+                    11,
+                  ],
+                  "type": "Identifier",
+                },
+                "typeParameters": undefined,
+              },
+            ],
+            "range": Array [
+              9,
+              12,
+            ],
+            "type": "TSTypeParameterInstantiation",
+          },
+        },
+        "loc": Object {
+          "end": Object {
+            "column": 9,
+            "line": 3,
+          },
+          "start": Object {
+            "column": 0,
+            "line": 3,
+          },
+        },
+        "range": Array [
+          7,
+          16,
+        ],
+        "type": "TSInstantiationExpression",
+        "typeParameters": Object {
+          "loc": Object {
+            "end": Object {
+              "column": 9,
+              "line": 3,
+            },
+            "start": Object {
+              "column": 6,
+              "line": 3,
+            },
+          },
+          "params": Array [
+            Object {
+              "loc": Object {
+                "end": Object {
+                  "column": 8,
+                  "line": 3,
+                },
+                "start": Object {
+                  "column": 7,
+                  "line": 3,
+                },
+              },
+              "range": Array [
+                14,
+                15,
+              ],
+              "type": "TSTypeReference",
+              "typeName": Object {
+                "loc": Object {
+                  "end": Object {
+                    "column": 8,
+                    "line": 3,
+                  },
+                  "start": Object {
+                    "column": 7,
+                    "line": 3,
+                  },
+                },
+                "name": "c",
+                "range": Array [
+                  14,
+                  15,
+                ],
+                "type": "Identifier",
+              },
+              "typeParameters": undefined,
+            },
+          ],
+          "range": Array [
+            13,
+            16,
+          ],
+          "type": "TSTypeParameterInstantiation",
+        },
+      },
+      "loc": Object {
+        "end": Object {
+          "column": 10,
+          "line": 3,
+        },
+        "start": Object {
+          "column": 0,
+          "line": 3,
+        },
+      },
+      "range": Array [
+        7,
+        17,
+      ],
+      "type": "ExpressionStatement",
+    },
+    Object {
+      "expression": Object {
+        "arguments": Array [],
+        "callee": Object {
+          "expression": Object {
+            "loc": Object {
+              "end": Object {
+                "column": 2,
+                "line": 4,
+              },
+              "start": Object {
+                "column": 1,
+                "line": 4,
+              },
+            },
+            "name": "a",
+            "range": Array [
+              19,
+              20,
+            ],
+            "type": "Identifier",
+          },
+          "loc": Object {
+            "end": Object {
+              "column": 5,
+              "line": 4,
+            },
+            "start": Object {
+              "column": 1,
+              "line": 4,
+            },
+          },
+          "range": Array [
+            19,
+            23,
+          ],
+          "type": "TSInstantiationExpression",
+          "typeParameters": Object {
+            "loc": Object {
+              "end": Object {
+                "column": 5,
+                "line": 4,
+              },
+              "start": Object {
+                "column": 2,
+                "line": 4,
+              },
+            },
+            "params": Array [
+              Object {
+                "loc": Object {
+                  "end": Object {
+                    "column": 4,
+                    "line": 4,
+                  },
+                  "start": Object {
+                    "column": 3,
+                    "line": 4,
+                  },
+                },
+                "range": Array [
+                  21,
+                  22,
+                ],
+                "type": "TSTypeReference",
+                "typeName": Object {
+                  "loc": Object {
+                    "end": Object {
+                      "column": 4,
+                      "line": 4,
+                    },
+                    "start": Object {
+                      "column": 3,
+                      "line": 4,
+                    },
+                  },
+                  "name": "b",
+                  "range": Array [
+                    21,
+                    22,
+                  ],
+                  "type": "Identifier",
+                },
+                "typeParameters": undefined,
+              },
+            ],
+            "range": Array [
+              20,
+              23,
+            ],
+            "type": "TSTypeParameterInstantiation",
+          },
+        },
+        "loc": Object {
+          "end": Object {
+            "column": 11,
+            "line": 4,
+          },
+          "start": Object {
+            "column": 0,
+            "line": 4,
+          },
+        },
+        "optional": false,
+        "range": Array [
+          18,
+          29,
+        ],
+        "type": "CallExpression",
+        "typeParameters": Object {
+          "loc": Object {
+            "end": Object {
+              "column": 9,
+              "line": 4,
+            },
+            "start": Object {
+              "column": 6,
+              "line": 4,
+            },
+          },
+          "params": Array [
+            Object {
+              "loc": Object {
+                "end": Object {
+                  "column": 8,
+                  "line": 4,
+                },
+                "start": Object {
+                  "column": 7,
+                  "line": 4,
+                },
+              },
+              "range": Array [
+                25,
+                26,
+              ],
+              "type": "TSTypeReference",
+              "typeName": Object {
+                "loc": Object {
+                  "end": Object {
+                    "column": 8,
+                    "line": 4,
+                  },
+                  "start": Object {
+                    "column": 7,
+                    "line": 4,
+                  },
+                },
+                "name": "c",
+                "range": Array [
+                  25,
+                  26,
+                ],
+                "type": "Identifier",
+              },
+              "typeParameters": undefined,
+            },
+          ],
+          "range": Array [
+            24,
+            27,
+          ],
+          "type": "TSTypeParameterInstantiation",
+        },
+      },
+      "loc": Object {
+        "end": Object {
+          "column": 12,
+          "line": 4,
+        },
+        "start": Object {
+          "column": 0,
+          "line": 4,
+        },
+      },
+      "range": Array [
+        18,
+        30,
+      ],
+      "type": "ExpressionStatement",
+    },
+    Object {
+      "expression": Object {
+        "expression": Object {
+          "arguments": Array [],
+          "callee": Object {
+            "expression": Object {
+              "expression": Object {
+                "loc": Object {
+                  "end": Object {
+                    "column": 2,
+                    "line": 5,
+                  },
+                  "start": Object {
+                    "column": 1,
+                    "line": 5,
+                  },
+                },
+                "name": "a",
+                "range": Array [
+                  32,
+                  33,
+                ],
+                "type": "Identifier",
+              },
+              "loc": Object {
+                "end": Object {
+                  "column": 5,
+                  "line": 5,
+                },
+                "start": Object {
+                  "column": 1,
+                  "line": 5,
+                },
+              },
+              "range": Array [
+                32,
+                36,
+              ],
+              "type": "TSInstantiationExpression",
+              "typeParameters": Object {
+                "loc": Object {
+                  "end": Object {
+                    "column": 5,
+                    "line": 5,
+                  },
+                  "start": Object {
+                    "column": 2,
+                    "line": 5,
+                  },
+                },
+                "params": Array [
+                  Object {
+                    "loc": Object {
+                      "end": Object {
+                        "column": 4,
+                        "line": 5,
+                      },
+                      "start": Object {
+                        "column": 3,
+                        "line": 5,
+                      },
+                    },
+                    "range": Array [
+                      34,
+                      35,
+                    ],
+                    "type": "TSTypeReference",
+                    "typeName": Object {
+                      "loc": Object {
+                        "end": Object {
+                          "column": 4,
+                          "line": 5,
+                        },
+                        "start": Object {
+                          "column": 3,
+                          "line": 5,
+                        },
+                      },
+                      "name": "b",
+                      "range": Array [
+                        34,
+                        35,
+                      ],
+                      "type": "Identifier",
+                    },
+                    "typeParameters": undefined,
+                  },
+                ],
+                "range": Array [
+                  33,
+                  36,
+                ],
+                "type": "TSTypeParameterInstantiation",
+              },
+            },
+            "loc": Object {
+              "end": Object {
+                "column": 9,
+                "line": 5,
+              },
+              "start": Object {
+                "column": 0,
+                "line": 5,
+              },
+            },
+            "range": Array [
+              31,
+              40,
+            ],
+            "type": "TSInstantiationExpression",
+            "typeParameters": Object {
+              "loc": Object {
+                "end": Object {
+                  "column": 9,
+                  "line": 5,
+                },
+                "start": Object {
+                  "column": 6,
+                  "line": 5,
+                },
+              },
+              "params": Array [
+                Object {
+                  "loc": Object {
+                    "end": Object {
+                      "column": 8,
+                      "line": 5,
+                    },
+                    "start": Object {
+                      "column": 7,
+                      "line": 5,
+                    },
+                  },
+                  "range": Array [
+                    38,
+                    39,
+                  ],
+                  "type": "TSTypeReference",
+                  "typeName": Object {
+                    "loc": Object {
+                      "end": Object {
+                        "column": 8,
+                        "line": 5,
+                      },
+                      "start": Object {
+                        "column": 7,
+                        "line": 5,
+                      },
+                    },
+                    "name": "c",
+                    "range": Array [
+                      38,
+                      39,
+                    ],
+                    "type": "Identifier",
+                  },
+                  "typeParameters": undefined,
+                },
+              ],
+              "range": Array [
+                37,
+                40,
+              ],
+              "type": "TSTypeParameterInstantiation",
+            },
+          },
+          "loc": Object {
+            "end": Object {
+              "column": 13,
+              "line": 5,
+            },
+            "start": Object {
+              "column": 0,
+              "line": 5,
+            },
+          },
+          "optional": true,
+          "range": Array [
+            31,
+            44,
+          ],
+          "type": "CallExpression",
+        },
+        "loc": Object {
+          "end": Object {
+            "column": 13,
+            "line": 5,
+          },
+          "start": Object {
+            "column": 0,
+            "line": 5,
+          },
+        },
+        "range": Array [
+          31,
+          44,
+        ],
+        "type": "ChainExpression",
+      },
+      "loc": Object {
+        "end": Object {
+          "column": 14,
+          "line": 5,
+        },
+        "start": Object {
+          "column": 0,
+          "line": 5,
+        },
+      },
+      "range": Array [
+        31,
+        45,
+      ],
+      "type": "ExpressionStatement",
+    },
+    Object {
+      "expression": Object {
+        "arguments": Array [],
+        "callee": Object {
+          "expression": Object {
+            "expression": Object {
+              "computed": false,
+              "loc": Object {
+                "end": Object {
+                  "column": 5,
+                  "line": 6,
+                },
+                "start": Object {
+                  "column": 1,
+                  "line": 6,
+                },
+              },
+              "object": Object {
+                "loc": Object {
+                  "end": Object {
+                    "column": 2,
+                    "line": 6,
+                  },
+                  "start": Object {
+                    "column": 1,
+                    "line": 6,
+                  },
+                },
+                "name": "a",
+                "range": Array [
+                  47,
+                  48,
+                ],
+                "type": "Identifier",
+              },
+              "optional": true,
+              "property": Object {
+                "loc": Object {
+                  "end": Object {
+                    "column": 5,
+                    "line": 6,
+                  },
+                  "start": Object {
+                    "column": 4,
+                    "line": 6,
+                  },
+                },
+                "name": "b",
+                "range": Array [
+                  50,
+                  51,
+                ],
+                "type": "Identifier",
+              },
+              "range": Array [
+                47,
+                51,
+              ],
+              "type": "MemberExpression",
+            },
+            "loc": Object {
+              "end": Object {
+                "column": 5,
+                "line": 6,
+              },
+              "start": Object {
+                "column": 1,
+                "line": 6,
+              },
+            },
+            "range": Array [
+              47,
+              51,
+            ],
+            "type": "ChainExpression",
+          },
+          "loc": Object {
+            "end": Object {
+              "column": 8,
+              "line": 6,
+            },
+            "start": Object {
+              "column": 1,
+              "line": 6,
+            },
+          },
+          "range": Array [
+            47,
+            54,
+          ],
+          "type": "TSInstantiationExpression",
+          "typeParameters": Object {
+            "loc": Object {
+              "end": Object {
+                "column": 8,
+                "line": 6,
+              },
+              "start": Object {
+                "column": 5,
+                "line": 6,
+              },
+            },
+            "params": Array [
+              Object {
+                "loc": Object {
+                  "end": Object {
+                    "column": 7,
+                    "line": 6,
+                  },
+                  "start": Object {
+                    "column": 6,
+                    "line": 6,
+                  },
+                },
+                "range": Array [
+                  52,
+                  53,
+                ],
+                "type": "TSTypeReference",
+                "typeName": Object {
+                  "loc": Object {
+                    "end": Object {
+                      "column": 7,
+                      "line": 6,
+                    },
+                    "start": Object {
+                      "column": 6,
+                      "line": 6,
+                    },
+                  },
+                  "name": "c",
+                  "range": Array [
+                    52,
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+        "end": Object {
+          "column": 5,
+          "line": 6,
+        },
+        "start": Object {
+          "column": 4,
+          "line": 6,
+        },
+      },
+      "range": Array [
+        50,
+        51,
+      ],
+      "type": "Identifier",
+      "value": "b",
+    },
+    Object {
+      "loc": Object {
+        "end": Object {
+          "column": 6,
+          "line": 6,
+        },
+        "start": Object {
+          "column": 5,
+          "line": 6,
+        },
+      },
+      "range": Array [
+        51,
+        52,
+      ],
+      "type": "Punctuator",
+      "value": "<",
+    },
+    Object {
+      "loc": Object {
+        "end": Object {
+          "column": 7,
+          "line": 6,
+        },
+        "start": Object {
+          "column": 6,
+          "line": 6,
+        },
+      },
+      "range": Array [
+        52,
+        53,
+      ],
+      "type": "Identifier",
+      "value": "c",
+    },
+    Object {
+      "loc": Object {
+        "end": Object {
+          "column": 8,
+          "line": 6,
+        },
+        "start": Object {
+          "column": 7,
+          "line": 6,
+        },
+      },
+      "range": Array [
+        53,
+        54,
+      ],
+      "type": "Punctuator",
+      "value": ">",
+    },
+    Object {
+      "loc": Object {
+        "end": Object {
+          "column": 9,
+          "line": 6,
+        },
+        "start": Object {
+          "column": 8,
+          "line": 6,
+        },
+      },
+      "range": Array [
+        54,
+        55,
+      ],
+      "type": "Punctuator",
+      "value": ")",
+    },
+    Object {
+      "loc": Object {
+        "end": Object {
+          "column": 10,
+          "line": 6,
+        },
+        "start": Object {
+          "column": 9,
+          "line": 6,
+        },
+      },
+      "range": Array [
+        55,
+        56,
+      ],
+      "type": "Punctuator",
+      "value": "<",
+    },
+    Object {
+      "loc": Object {
+        "end": Object {
+          "column": 11,
+          "line": 6,
+        },
+        "start": Object {
+          "column": 10,
+          "line": 6,
+        },
+      },
+      "range": Array [
+        56,
+        57,
+      ],
+      "type": "Identifier",
+      "value": "d",
+    },
+    Object {
+      "loc": Object {
+        "end": Object {
+          "column": 12,
+          "line": 6,
+        },
+        "start": Object {
+          "column": 11,
+          "line": 6,
+        },
+      },
+      "range": Array [
+        57,
+        58,
+      ],
+      "type": "Punctuator",
+      "value": ">",
+    },
+    Object {
+      "loc": Object {
+        "end": Object {
+          "column": 13,
+          "line": 6,
+        },
+        "start": Object {
+          "column": 12,
+          "line": 6,
+        },
+      },
+      "range": Array [
+        58,
+        59,
+      ],
+      "type": "Punctuator",
+      "value": "(",
+    },
+    Object {
+      "loc": Object {
+        "end": Object {
+          "column": 14,
+          "line": 6,
+        },
+        "start": Object {
+          "column": 13,
+          "line": 6,
+        },
+      },
+      "range": Array [
+        59,
+        60,
+      ],
+      "type": "Punctuator",
+      "value": ")",
+    },
+    Object {
+      "loc": Object {
+        "end": Object {
+          "column": 15,
+          "line": 6,
+        },
+        "start": Object {
+          "column": 14,
+          "line": 6,
+        },
+      },
+      "range": Array [
+        60,
+        61,
+      ],
+      "type": "Punctuator",
+      "value": ";",
+    },
+    Object {
+      "loc": Object {
+        "end": Object {
+          "column": 3,
+          "line": 7,
+        },
+        "start": Object {
+          "column": 0,
+          "line": 7,
+        },
+      },
+      "range": Array [
+        62,
+        65,
+      ],
+      "type": "Keyword",
+      "value": "new",
+    },
+    Object {
+      "loc": Object {
+        "end": Object {
+          "column": 5,
+          "line": 7,
+        },
+        "start": Object {
+          "column": 4,
+          "line": 7,
+        },
+      },
+      "range": Array [
+        66,
+        67,
+      ],
+      "type": "Punctuator",
+      "value": "(",
+    },
+    Object {
+      "loc": Object {
+        "end": Object {
+          "column": 6,
+          "line": 7,
+        },
+        "start": Object {
+          "column": 5,
+          "line": 7,
+        },
+      },
+      "range": Array [
+        67,
+        68,
+      ],
+      "type": "Identifier",
+      "value": "a",
+    },
+    Object {
+      "loc": Object {
+        "end": Object {
+          "column": 7,
+          "line": 7,
+        },
+        "start": Object {
+          "column": 6,
+          "line": 7,
+        },
+      },
+      "range": Array [
+        68,
+        69,
+      ],
+      "type": "Punctuator",
+      "value": "<",
+    },
+    Object {
+      "loc": Object {
+        "end": Object {
+          "column": 8,
+          "line": 7,
+        },
+        "start": Object {
+          "column": 7,
+          "line": 7,
+        },
+      },
+      "range": Array [
+        69,
+        70,
+      ],
+      "type": "Identifier",
+      "value": "b",
+    },
+    Object {
+      "loc": Object {
+        "end": Object {
+          "column": 9,
+          "line": 7,
+        },
+        "start": Object {
+          "column": 8,
+          "line": 7,
+        },
+      },
+      "range": Array [
+        70,
+        71,
+      ],
+      "type": "Punctuator",
+      "value": ">",
+    },
+    Object {
+      "loc": Object {
+        "end": Object {
+          "column": 10,
+          "line": 7,
+        },
+        "start": Object {
+          "column": 9,
+          "line": 7,
+        },
+      },
+      "range": Array [
+        71,
+        72,
+      ],
+      "type": "Punctuator",
+      "value": ")",
+    },
+    Object {
+      "loc": Object {
+        "end": Object {
+          "column": 11,
+          "line": 7,
+        },
+        "start": Object {
+          "column": 10,
+          "line": 7,
+        },
+      },
+      "range": Array [
+        72,
+        73,
+      ],
+      "type": "Punctuator",
+      "value": "<",
+    },
+    Object {
+      "loc": Object {
+        "end": Object {
+          "column": 12,
+          "line": 7,
+        },
+        "start": Object {
+          "column": 11,
+          "line": 7,
+        },
+      },
+      "range": Array [
+        73,
+        74,
+      ],
+      "type": "Identifier",
+      "value": "c",
+    },
+    Object {
+      "loc": Object {
+        "end": Object {
+          "column": 13,
+          "line": 7,
+        },
+        "start": Object {
+          "column": 12,
+          "line": 7,
+        },
+      },
+      "range": Array [
+        74,
+        75,
+      ],
+      "type": "Punctuator",
+      "value": ">",
+    },
+    Object {
+      "loc": Object {
+        "end": Object {
+          "column": 14,
+          "line": 7,
+        },
+        "start": Object {
+          "column": 13,
+          "line": 7,
+        },
+      },
+      "range": Array [
+        75,
+        76,
+      ],
+      "type": "Punctuator",
+      "value": "(",
+    },
+    Object {
+      "loc": Object {
+        "end": Object {
+          "column": 15,
+          "line": 7,
+        },
+        "start": Object {
+          "column": 14,
+          "line": 7,
+        },
+      },
+      "range": Array [
+        76,
+        77,
+      ],
+      "type": "Punctuator",
+      "value": ")",
+    },
+    Object {
+      "loc": Object {
+        "end": Object {
+          "column": 16,
+          "line": 7,
+        },
+        "start": Object {
+          "column": 15,
+          "line": 7,
+        },
+      },
+      "range": Array [
+        77,
+        78,
+      ],
+      "type": "Punctuator",
+      "value": ";",
+    },
+  ],
+  "type": "Program",
+}
+`;
diff --git a/packages/typescript-estree/tests/snapshots/typescript/basics/interface-type-parameters.src.ts.shot b/packages/typescript-estree/tests/snapshots/typescript/basics/interface-type-parameters.src.ts.shot
index 382d69ac3d40..f1d74ce8b70c 100644
--- a/packages/typescript-estree/tests/snapshots/typescript/basics/interface-type-parameters.src.ts.shot
+++ b/packages/typescript-estree/tests/snapshots/typescript/basics/interface-type-parameters.src.ts.shot
@@ -70,6 +70,7 @@ Object {
           Object {
             "constraint": undefined,
             "default": undefined,
+            "in": false,
             "loc": Object {
               "end": Object {
                 "column": 15,
@@ -98,6 +99,7 @@ Object {
               ],
               "type": "Identifier",
             },
+            "out": false,
             "range": Array [
               14,
               15,
diff --git a/packages/typescript-estree/tests/snapshots/typescript/basics/interface-with-all-property-types.src.ts.shot b/packages/typescript-estree/tests/snapshots/typescript/basics/interface-with-all-property-types.src.ts.shot
index dece748c4b2d..8c772c7947a8 100644
--- a/packages/typescript-estree/tests/snapshots/typescript/basics/interface-with-all-property-types.src.ts.shot
+++ b/packages/typescript-estree/tests/snapshots/typescript/basics/interface-with-all-property-types.src.ts.shot
@@ -880,6 +880,7 @@ Object {
                 Object {
                   "constraint": undefined,
                   "default": undefined,
+                  "in": false,
                   "loc": Object {
                     "end": Object {
                       "column": 9,
@@ -908,6 +909,7 @@ Object {
                     ],
                     "type": "Identifier",
                   },
+                  "out": false,
                   "range": Array [
                     194,
                     195,
@@ -1116,6 +1118,7 @@ Object {
                 Object {
                   "constraint": undefined,
                   "default": undefined,
+                  "in": false,
                   "loc": Object {
                     "end": Object {
                       "column": 10,
@@ -1144,6 +1147,7 @@ Object {
                     ],
                     "type": "Identifier",
                   },
+                  "out": false,
                   "range": Array [
                     247,
                     248,
diff --git a/packages/typescript-estree/tests/snapshots/typescript/basics/interface-with-extends-type-parameters.src.ts.shot b/packages/typescript-estree/tests/snapshots/typescript/basics/interface-with-extends-type-parameters.src.ts.shot
index 4cb2e5a2a089..5ac92facdff7 100644
--- a/packages/typescript-estree/tests/snapshots/typescript/basics/interface-with-extends-type-parameters.src.ts.shot
+++ b/packages/typescript-estree/tests/snapshots/typescript/basics/interface-with-extends-type-parameters.src.ts.shot
@@ -162,6 +162,7 @@ Object {
           Object {
             "constraint": undefined,
             "default": undefined,
+            "in": false,
             "loc": Object {
               "end": Object {
                 "column": 15,
@@ -190,6 +191,7 @@ Object {
               ],
               "type": "Identifier",
             },
+            "out": false,
             "range": Array [
               14,
               15,
diff --git a/packages/typescript-estree/tests/snapshots/typescript/basics/interface-with-generic.src.ts.shot b/packages/typescript-estree/tests/snapshots/typescript/basics/interface-with-generic.src.ts.shot
index 1ee99f876aaf..3c1d50e28b29 100644
--- a/packages/typescript-estree/tests/snapshots/typescript/basics/interface-with-generic.src.ts.shot
+++ b/packages/typescript-estree/tests/snapshots/typescript/basics/interface-with-generic.src.ts.shot
@@ -70,6 +70,7 @@ Object {
           Object {
             "constraint": undefined,
             "default": undefined,
+            "in": false,
             "loc": Object {
               "end": Object {
                 "column": 16,
@@ -98,6 +99,7 @@ Object {
               ],
               "type": "Identifier",
             },
+            "out": false,
             "range": Array [
               15,
               16,
diff --git a/packages/typescript-estree/tests/snapshots/typescript/basics/interface-with-method.src.ts.shot b/packages/typescript-estree/tests/snapshots/typescript/basics/interface-with-method.src.ts.shot
index f94e34982985..fdc32c023359 100644
--- a/packages/typescript-estree/tests/snapshots/typescript/basics/interface-with-method.src.ts.shot
+++ b/packages/typescript-estree/tests/snapshots/typescript/basics/interface-with-method.src.ts.shot
@@ -308,6 +308,7 @@ Object {
                 Object {
                   "constraint": undefined,
                   "default": undefined,
+                  "in": false,
                   "loc": Object {
                     "end": Object {
                       "column": 5,
@@ -336,6 +337,7 @@ Object {
                     ],
                     "type": "Identifier",
                   },
+                  "out": false,
                   "range": Array [
                     45,
                     46,
diff --git a/packages/typescript-estree/tests/snapshots/typescript/basics/intrinsic-keyword.src.ts.shot b/packages/typescript-estree/tests/snapshots/typescript/basics/intrinsic-keyword.src.ts.shot
index 22d41df5f1a2..5b885e496dfb 100644
--- a/packages/typescript-estree/tests/snapshots/typescript/basics/intrinsic-keyword.src.ts.shot
+++ b/packages/typescript-estree/tests/snapshots/typescript/basics/intrinsic-keyword.src.ts.shot
@@ -85,6 +85,7 @@ Object {
               "type": "TSStringKeyword",
             },
             "default": undefined,
+            "in": false,
             "loc": Object {
               "end": Object {
                 "column": 31,
@@ -113,6 +114,7 @@ Object {
               ],
               "type": "Identifier",
             },
+            "out": false,
             "range": Array [
               15,
               31,
@@ -209,6 +211,7 @@ Object {
               "type": "TSStringKeyword",
             },
             "default": undefined,
+            "in": false,
             "loc": Object {
               "end": Object {
                 "column": 31,
@@ -237,6 +240,7 @@ Object {
               ],
               "type": "Identifier",
             },
+            "out": false,
             "range": Array [
               61,
               77,
@@ -333,6 +337,7 @@ Object {
               "type": "TSStringKeyword",
             },
             "default": undefined,
+            "in": false,
             "loc": Object {
               "end": Object {
                 "column": 32,
@@ -361,6 +366,7 @@ Object {
               ],
               "type": "Identifier",
             },
+            "out": false,
             "range": Array [
               108,
               124,
@@ -457,6 +463,7 @@ Object {
               "type": "TSStringKeyword",
             },
             "default": undefined,
+            "in": false,
             "loc": Object {
               "end": Object {
                 "column": 34,
@@ -485,6 +492,7 @@ Object {
               ],
               "type": "Identifier",
             },
+            "out": false,
             "range": Array [
               157,
               173,
diff --git a/packages/typescript-estree/tests/snapshots/typescript/basics/object-with-typed-methods.src.ts.shot b/packages/typescript-estree/tests/snapshots/typescript/basics/object-with-typed-methods.src.ts.shot
index 33dc823fd720..bafe11a59fd1 100644
--- a/packages/typescript-estree/tests/snapshots/typescript/basics/object-with-typed-methods.src.ts.shot
+++ b/packages/typescript-estree/tests/snapshots/typescript/basics/object-with-typed-methods.src.ts.shot
@@ -200,6 +200,7 @@ Object {
                       Object {
                         "constraint": undefined,
                         "default": undefined,
+                        "in": false,
                         "loc": Object {
                           "end": Object {
                             "column": 17,
@@ -228,6 +229,7 @@ Object {
                           ],
                           "type": "Identifier",
                         },
+                        "out": false,
                         "range": Array [
                           30,
                           31,
@@ -406,6 +408,7 @@ Object {
                       Object {
                         "constraint": undefined,
                         "default": undefined,
+                        "in": false,
                         "loc": Object {
                           "end": Object {
                             "column": 7,
@@ -434,6 +437,7 @@ Object {
                           ],
                           "type": "Identifier",
                         },
+                        "out": false,
                         "range": Array [
                           69,
                           70,
diff --git a/packages/typescript-estree/tests/snapshots/typescript/basics/type-alias-declaration-with-constrained-type-parameter.src.ts.shot b/packages/typescript-estree/tests/snapshots/typescript/basics/type-alias-declaration-with-constrained-type-parameter.src.ts.shot
index 709a4cc36a64..d2c6248a377c 100644
--- a/packages/typescript-estree/tests/snapshots/typescript/basics/type-alias-declaration-with-constrained-type-parameter.src.ts.shot
+++ b/packages/typescript-estree/tests/snapshots/typescript/basics/type-alias-declaration-with-constrained-type-parameter.src.ts.shot
@@ -214,6 +214,7 @@ Object {
               "type": "TSTypeLiteral",
             },
             "default": undefined,
+            "in": false,
             "loc": Object {
               "end": Object {
                 "column": 24,
@@ -242,6 +243,7 @@ Object {
               ],
               "type": "Identifier",
             },
+            "out": false,
             "range": Array [
               12,
               24,
diff --git a/packages/typescript-estree/tests/snapshots/typescript/basics/type-alias-declaration.src.ts.shot b/packages/typescript-estree/tests/snapshots/typescript/basics/type-alias-declaration.src.ts.shot
index b97bf6d4afd6..169e2a2c6f63 100644
--- a/packages/typescript-estree/tests/snapshots/typescript/basics/type-alias-declaration.src.ts.shot
+++ b/packages/typescript-estree/tests/snapshots/typescript/basics/type-alias-declaration.src.ts.shot
@@ -197,6 +197,7 @@ Object {
           Object {
             "constraint": undefined,
             "default": undefined,
+            "in": false,
             "loc": Object {
               "end": Object {
                 "column": 13,
@@ -225,6 +226,7 @@ Object {
               ],
               "type": "Identifier",
             },
+            "out": false,
             "range": Array [
               12,
               13,
diff --git a/packages/typescript-estree/tests/snapshots/typescript/basics/type-parameters-comments-heritage.src.ts.shot b/packages/typescript-estree/tests/snapshots/typescript/basics/type-parameters-comments-heritage.src.ts.shot
index d244e9e147f8..9ac707ba48f9 100644
--- a/packages/typescript-estree/tests/snapshots/typescript/basics/type-parameters-comments-heritage.src.ts.shot
+++ b/packages/typescript-estree/tests/snapshots/typescript/basics/type-parameters-comments-heritage.src.ts.shot
@@ -143,6 +143,7 @@ Object {
           Object {
             "constraint": undefined,
             "default": undefined,
+            "in": false,
             "loc": Object {
               "end": Object {
                 "column": 23,
@@ -171,6 +172,7 @@ Object {
               ],
               "type": "Identifier",
             },
+            "out": false,
             "range": Array [
               22,
               23,
@@ -360,6 +362,7 @@ Object {
               ],
               "type": "TSLiteralType",
             },
+            "in": false,
             "loc": Object {
               "end": Object {
                 "column": 38,
@@ -388,6 +391,7 @@ Object {
               ],
               "type": "Identifier",
             },
+            "out": false,
             "range": Array [
               98,
               113,
@@ -561,6 +565,7 @@ Object {
           Object {
             "constraint": undefined,
             "default": undefined,
+            "in": false,
             "loc": Object {
               "end": Object {
                 "column": 27,
@@ -589,6 +594,7 @@ Object {
               ],
               "type": "Identifier",
             },
+            "out": false,
             "range": Array [
               191,
               192,
@@ -797,6 +803,7 @@ Object {
               ],
               "type": "TSLiteralType",
             },
+            "in": false,
             "loc": Object {
               "end": Object {
                 "column": 42,
@@ -825,6 +832,7 @@ Object {
               ],
               "type": "Identifier",
             },
+            "out": false,
             "range": Array [
               272,
               287,
diff --git a/packages/typescript-estree/tests/snapshots/typescript/basics/type-parameters-comments.src.ts.shot b/packages/typescript-estree/tests/snapshots/typescript/basics/type-parameters-comments.src.ts.shot
index e4dc865f2b61..23e4e8cfe5c5 100644
--- a/packages/typescript-estree/tests/snapshots/typescript/basics/type-parameters-comments.src.ts.shot
+++ b/packages/typescript-estree/tests/snapshots/typescript/basics/type-parameters-comments.src.ts.shot
@@ -183,6 +183,7 @@ Object {
           Object {
             "constraint": undefined,
             "default": undefined,
+            "in": false,
             "loc": Object {
               "end": Object {
                 "column": 25,
@@ -211,6 +212,7 @@ Object {
               ],
               "type": "Identifier",
             },
+            "out": false,
             "range": Array [
               68,
               69,
@@ -331,6 +333,7 @@ Object {
               },
               "typeParameters": undefined,
             },
+            "in": false,
             "loc": Object {
               "end": Object {
                 "column": 41,
@@ -359,6 +362,7 @@ Object {
               ],
               "type": "Identifier",
             },
+            "out": false,
             "range": Array [
               112,
               129,
diff --git a/packages/typescript-estree/tests/snapshots/typescript/basics/typed-method-signature.src.ts.shot b/packages/typescript-estree/tests/snapshots/typescript/basics/typed-method-signature.src.ts.shot
index a175d632669d..45a7d8515871 100644
--- a/packages/typescript-estree/tests/snapshots/typescript/basics/typed-method-signature.src.ts.shot
+++ b/packages/typescript-estree/tests/snapshots/typescript/basics/typed-method-signature.src.ts.shot
@@ -351,6 +351,7 @@ Object {
                 Object {
                   "constraint": undefined,
                   "default": undefined,
+                  "in": false,
                   "loc": Object {
                     "end": Object {
                       "column": 5,
@@ -379,6 +380,7 @@ Object {
                     ],
                     "type": "Identifier",
                   },
+                  "out": false,
                   "range": Array [
                     41,
                     42,
diff --git a/packages/typescript-estree/tests/snapshots/typescript/expressions/instantiation-expression.src.ts.shot b/packages/typescript-estree/tests/snapshots/typescript/expressions/instantiation-expression.src.ts.shot
new file mode 100644
index 000000000000..25904ece493d
--- /dev/null
+++ b/packages/typescript-estree/tests/snapshots/typescript/expressions/instantiation-expression.src.ts.shot
@@ -0,0 +1,2330 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`typescript expressions instantiation-expression.src 1`] = `
+Object {
+  "body": Array [
+    Object {
+      "expression": Object {
+        "expression": Object {
+          "loc": Object {
+            "end": Object {
+              "column": 1,
+              "line": 1,
+            },
+            "start": Object {
+              "column": 0,
+              "line": 1,
+            },
+          },
+          "name": "a",
+          "range": Array [
+            0,
+            1,
+          ],
+          "type": "Identifier",
+        },
+        "loc": Object {
+          "end": Object {
+            "column": 4,
+            "line": 1,
+          },
+          "start": Object {
+            "column": 0,
+            "line": 1,
+          },
+        },
+        "range": Array [
+          0,
+          4,
+        ],
+        "type": "TSInstantiationExpression",
+        "typeParameters": Object {
+          "loc": Object {
+            "end": Object {
+              "column": 4,
+              "line": 1,
+            },
+            "start": Object {
+              "column": 1,
+              "line": 1,
+            },
+          },
+          "params": Array [
+            Object {
+              "loc": Object {
+                "end": Object {
+                  "column": 3,
+                  "line": 1,
+                },
+                "start": Object {
+                  "column": 2,
+                  "line": 1,
+                },
+              },
+              "range": Array [
+                2,
+                3,
+              ],
+              "type": "TSTypeReference",
+              "typeName": Object {
+                "loc": Object {
+                  "end": Object {
+                    "column": 3,
+                    "line": 1,
+                  },
+                  "start": Object {
+                    "column": 2,
+                    "line": 1,
+                  },
+                },
+                "name": "b",
+                "range": Array [
+                  2,
+                  3,
+                ],
+                "type": "Identifier",
+              },
+              "typeParameters": undefined,
+            },
+          ],
+          "range": Array [
+            1,
+            4,
+          ],
+          "type": "TSTypeParameterInstantiation",
+        },
+      },
+      "loc": Object {
+        "end": Object {
+          "column": 5,
+          "line": 1,
+        },
+        "start": Object {
+          "column": 0,
+          "line": 1,
+        },
+      },
+      "range": Array [
+        0,
+        5,
+      ],
+      "type": "ExpressionStatement",
+    },
+    Object {
+      "expression": Object {
+        "expression": Object {
+          "expression": Object {
+            "loc": Object {
+              "end": Object {
+                "column": 2,
+                "line": 3,
+              },
+              "start": Object {
+                "column": 1,
+                "line": 3,
+              },
+            },
+            "name": "a",
+            "range": Array [
+              8,
+              9,
+            ],
+            "type": "Identifier",
+          },
+          "loc": Object {
+            "end": Object {
+              "column": 5,
+              "line": 3,
+            },
+            "start": Object {
+              "column": 1,
+              "line": 3,
+            },
+          },
+          "range": Array [
+            8,
+            12,
+          ],
+          "type": "TSInstantiationExpression",
+          "typeParameters": Object {
+            "loc": Object {
+              "end": Object {
+                "column": 5,
+                "line": 3,
+              },
+              "start": Object {
+                "column": 2,
+                "line": 3,
+              },
+            },
+            "params": Array [
+              Object {
+                "loc": Object {
+                  "end": Object {
+                    "column": 4,
+                    "line": 3,
+                  },
+                  "start": Object {
+                    "column": 3,
+                    "line": 3,
+                  },
+                },
+                "range": Array [
+                  10,
+                  11,
+                ],
+                "type": "TSTypeReference",
+                "typeName": Object {
+                  "loc": Object {
+                    "end": Object {
+                      "column": 4,
+                      "line": 3,
+                    },
+                    "start": Object {
+                      "column": 3,
+                      "line": 3,
+                    },
+                  },
+                  "name": "b",
+                  "range": Array [
+                    10,
+                    11,
+                  ],
+                  "type": "Identifier",
+                },
+                "typeParameters": undefined,
+              },
+            ],
+            "range": Array [
+              9,
+              12,
+            ],
+            "type": "TSTypeParameterInstantiation",
+          },
+        },
+        "loc": Object {
+          "end": Object {
+            "column": 9,
+            "line": 3,
+          },
+          "start": Object {
+            "column": 0,
+            "line": 3,
+          },
+        },
+        "range": Array [
+          7,
+          16,
+        ],
+        "type": "TSInstantiationExpression",
+        "typeParameters": Object {
+          "loc": Object {
+            "end": Object {
+              "column": 9,
+              "line": 3,
+            },
+            "start": Object {
+              "column": 6,
+              "line": 3,
+            },
+          },
+          "params": Array [
+            Object {
+              "loc": Object {
+                "end": Object {
+                  "column": 8,
+                  "line": 3,
+                },
+                "start": Object {
+                  "column": 7,
+                  "line": 3,
+                },
+              },
+              "range": Array [
+                14,
+                15,
+              ],
+              "type": "TSTypeReference",
+              "typeName": Object {
+                "loc": Object {
+                  "end": Object {
+                    "column": 8,
+                    "line": 3,
+                  },
+                  "start": Object {
+                    "column": 7,
+                    "line": 3,
+                  },
+                },
+                "name": "c",
+                "range": Array [
+                  14,
+                  15,
+                ],
+                "type": "Identifier",
+              },
+              "typeParameters": undefined,
+            },
+          ],
+          "range": Array [
+            13,
+            16,
+          ],
+          "type": "TSTypeParameterInstantiation",
+        },
+      },
+      "loc": Object {
+        "end": Object {
+          "column": 10,
+          "line": 3,
+        },
+        "start": Object {
+          "column": 0,
+          "line": 3,
+        },
+      },
+      "range": Array [
+        7,
+        17,
+      ],
+      "type": "ExpressionStatement",
+    },
+    Object {
+      "expression": Object {
+        "arguments": Array [],
+        "callee": Object {
+          "expression": Object {
+            "loc": Object {
+              "end": Object {
+                "column": 2,
+                "line": 4,
+              },
+              "start": Object {
+                "column": 1,
+                "line": 4,
+              },
+            },
+            "name": "a",
+            "range": Array [
+              19,
+              20,
+            ],
+            "type": "Identifier",
+          },
+          "loc": Object {
+            "end": Object {
+              "column": 5,
+              "line": 4,
+            },
+            "start": Object {
+              "column": 1,
+              "line": 4,
+            },
+          },
+          "range": Array [
+            19,
+            23,
+          ],
+          "type": "TSInstantiationExpression",
+          "typeParameters": Object {
+            "loc": Object {
+              "end": Object {
+                "column": 5,
+                "line": 4,
+              },
+              "start": Object {
+                "column": 2,
+                "line": 4,
+              },
+            },
+            "params": Array [
+              Object {
+                "loc": Object {
+                  "end": Object {
+                    "column": 4,
+                    "line": 4,
+                  },
+                  "start": Object {
+                    "column": 3,
+                    "line": 4,
+                  },
+                },
+                "range": Array [
+                  21,
+                  22,
+                ],
+                "type": "TSTypeReference",
+                "typeName": Object {
+                  "loc": Object {
+                    "end": Object {
+                      "column": 4,
+                      "line": 4,
+                    },
+                    "start": Object {
+                      "column": 3,
+                      "line": 4,
+                    },
+                  },
+                  "name": "b",
+                  "range": Array [
+                    21,
+                    22,
+                  ],
+                  "type": "Identifier",
+                },
+                "typeParameters": undefined,
+              },
+            ],
+            "range": Array [
+              20,
+              23,
+            ],
+            "type": "TSTypeParameterInstantiation",
+          },
+        },
+        "loc": Object {
+          "end": Object {
+            "column": 11,
+            "line": 4,
+          },
+          "start": Object {
+            "column": 0,
+            "line": 4,
+          },
+        },
+        "optional": false,
+        "range": Array [
+          18,
+          29,
+        ],
+        "type": "CallExpression",
+        "typeParameters": Object {
+          "loc": Object {
+            "end": Object {
+              "column": 9,
+              "line": 4,
+            },
+            "start": Object {
+              "column": 6,
+              "line": 4,
+            },
+          },
+          "params": Array [
+            Object {
+              "loc": Object {
+                "end": Object {
+                  "column": 8,
+                  "line": 4,
+                },
+                "start": Object {
+                  "column": 7,
+                  "line": 4,
+                },
+              },
+              "range": Array [
+                25,
+                26,
+              ],
+              "type": "TSTypeReference",
+              "typeName": Object {
+                "loc": Object {
+                  "end": Object {
+                    "column": 8,
+                    "line": 4,
+                  },
+                  "start": Object {
+                    "column": 7,
+                    "line": 4,
+                  },
+                },
+                "name": "c",
+                "range": Array [
+                  25,
+                  26,
+                ],
+                "type": "Identifier",
+              },
+              "typeParameters": undefined,
+            },
+          ],
+          "range": Array [
+            24,
+            27,
+          ],
+          "type": "TSTypeParameterInstantiation",
+        },
+      },
+      "loc": Object {
+        "end": Object {
+          "column": 12,
+          "line": 4,
+        },
+        "start": Object {
+          "column": 0,
+          "line": 4,
+        },
+      },
+      "range": Array [
+        18,
+        30,
+      ],
+      "type": "ExpressionStatement",
+    },
+    Object {
+      "expression": Object {
+        "expression": Object {
+          "arguments": Array [],
+          "callee": Object {
+            "expression": Object {
+              "expression": Object {
+                "loc": Object {
+                  "end": Object {
+                    "column": 2,
+                    "line": 5,
+                  },
+                  "start": Object {
+                    "column": 1,
+                    "line": 5,
+                  },
+                },
+                "name": "a",
+                "range": Array [
+                  32,
+                  33,
+                ],
+                "type": "Identifier",
+              },
+              "loc": Object {
+                "end": Object {
+                  "column": 5,
+                  "line": 5,
+                },
+                "start": Object {
+                  "column": 1,
+                  "line": 5,
+                },
+              },
+              "range": Array [
+                32,
+                36,
+              ],
+              "type": "TSInstantiationExpression",
+              "typeParameters": Object {
+                "loc": Object {
+                  "end": Object {
+                    "column": 5,
+                    "line": 5,
+                  },
+                  "start": Object {
+                    "column": 2,
+                    "line": 5,
+                  },
+                },
+                "params": Array [
+                  Object {
+                    "loc": Object {
+                      "end": Object {
+                        "column": 4,
+                        "line": 5,
+                      },
+                      "start": Object {
+                        "column": 3,
+                        "line": 5,
+                      },
+                    },
+                    "range": Array [
+                      34,
+                      35,
+                    ],
+                    "type": "TSTypeReference",
+                    "typeName": Object {
+                      "loc": Object {
+                        "end": Object {
+                          "column": 4,
+                          "line": 5,
+                        },
+                        "start": Object {
+                          "column": 3,
+                          "line": 5,
+                        },
+                      },
+                      "name": "b",
+                      "range": Array [
+                        34,
+                        35,
+                      ],
+                      "type": "Identifier",
+                    },
+                    "typeParameters": undefined,
+                  },
+                ],
+                "range": Array [
+                  33,
+                  36,
+                ],
+                "type": "TSTypeParameterInstantiation",
+              },
+            },
+            "loc": Object {
+              "end": Object {
+                "column": 9,
+                "line": 5,
+              },
+              "start": Object {
+                "column": 0,
+                "line": 5,
+              },
+            },
+            "range": Array [
+              31,
+              40,
+            ],
+            "type": "TSInstantiationExpression",
+            "typeParameters": Object {
+              "loc": Object {
+                "end": Object {
+                  "column": 9,
+                  "line": 5,
+                },
+                "start": Object {
+                  "column": 6,
+                  "line": 5,
+                },
+              },
+              "params": Array [
+                Object {
+                  "loc": Object {
+                    "end": Object {
+                      "column": 8,
+                      "line": 5,
+                    },
+                    "start": Object {
+                      "column": 7,
+                      "line": 5,
+                    },
+                  },
+                  "range": Array [
+                    38,
+                    39,
+                  ],
+                  "type": "TSTypeReference",
+                  "typeName": Object {
+                    "loc": Object {
+                      "end": Object {
+                        "column": 8,
+                        "line": 5,
+                      },
+                      "start": Object {
+                        "column": 7,
+                        "line": 5,
+                      },
+                    },
+                    "name": "c",
+                    "range": Array [
+                      38,
+                      39,
+                    ],
+                    "type": "Identifier",
+                  },
+                  "typeParameters": undefined,
+                },
+              ],
+              "range": Array [
+                37,
+                40,
+              ],
+              "type": "TSTypeParameterInstantiation",
+            },
+          },
+          "loc": Object {
+            "end": Object {
+              "column": 13,
+              "line": 5,
+            },
+            "start": Object {
+              "column": 0,
+              "line": 5,
+            },
+          },
+          "optional": true,
+          "range": Array [
+            31,
+            44,
+          ],
+          "type": "CallExpression",
+        },
+        "loc": Object {
+          "end": Object {
+            "column": 13,
+            "line": 5,
+          },
+          "start": Object {
+            "column": 0,
+            "line": 5,
+          },
+        },
+        "range": Array [
+          31,
+          44,
+        ],
+        "type": "ChainExpression",
+      },
+      "loc": Object {
+        "end": Object {
+          "column": 14,
+          "line": 5,
+        },
+        "start": Object {
+          "column": 0,
+          "line": 5,
+        },
+      },
+      "range": Array [
+        31,
+        45,
+      ],
+      "type": "ExpressionStatement",
+    },
+    Object {
+      "expression": Object {
+        "arguments": Array [],
+        "callee": Object {
+          "expression": Object {
+            "expression": Object {
+              "computed": false,
+              "loc": Object {
+                "end": Object {
+                  "column": 5,
+                  "line": 6,
+                },
+                "start": Object {
+                  "column": 1,
+                  "line": 6,
+                },
+              },
+              "object": Object {
+                "loc": Object {
+                  "end": Object {
+                    "column": 2,
+                    "line": 6,
+                  },
+                  "start": Object {
+                    "column": 1,
+                    "line": 6,
+                  },
+                },
+                "name": "a",
+                "range": Array [
+                  47,
+                  48,
+                ],
+                "type": "Identifier",
+              },
+              "optional": true,
+              "property": Object {
+                "loc": Object {
+                  "end": Object {
+                    "column": 5,
+                    "line": 6,
+                  },
+                  "start": Object {
+                    "column": 4,
+                    "line": 6,
+                  },
+                },
+                "name": "b",
+                "range": Array [
+                  50,
+                  51,
+                ],
+                "type": "Identifier",
+              },
+              "range": Array [
+                47,
+                51,
+              ],
+              "type": "MemberExpression",
+            },
+            "loc": Object {
+              "end": Object {
+                "column": 5,
+                "line": 6,
+              },
+              "start": Object {
+                "column": 1,
+                "line": 6,
+              },
+            },
+            "range": Array [
+              47,
+              51,
+            ],
+            "type": "ChainExpression",
+          },
+          "loc": Object {
+            "end": Object {
+              "column": 8,
+              "line": 6,
+            },
+            "start": Object {
+              "column": 1,
+              "line": 6,
+            },
+          },
+          "range": Array [
+            47,
+            54,
+          ],
+          "type": "TSInstantiationExpression",
+          "typeParameters": Object {
+            "loc": Object {
+              "end": Object {
+                "column": 8,
+                "line": 6,
+              },
+              "start": Object {
+                "column": 5,
+                "line": 6,
+              },
+            },
+            "params": Array [
+              Object {
+                "loc": Object {
+                  "end": Object {
+                    "column": 7,
+                    "line": 6,
+                  },
+                  "start": Object {
+                    "column": 6,
+                    "line": 6,
+                  },
+                },
+                "range": Array [
+                  52,
+                  53,
+                ],
+                "type": "TSTypeReference",
+                "typeName": Object {
+                  "loc": Object {
+                    "end": Object {
+                      "column": 7,
+                      "line": 6,
+                    },
+                    "start": Object {
+                      "column": 6,
+                      "line": 6,
+                    },
+                  },
+                  "name": "c",
+                  "range": Array [
+                    52,
+                    53,
+                  ],
+                  "type": "Identifier",
+                },
+                "typeParameters": undefined,
+              },
+            ],
+            "range": Array [
+              51,
+              54,
+            ],
+            "type": "TSTypeParameterInstantiation",
+          },
+        },
+        "loc": Object {
+          "end": Object {
+            "column": 14,
+            "line": 6,
+          },
+          "start": Object {
+            "column": 0,
+            "line": 6,
+          },
+        },
+        "optional": false,
+        "range": Array [
+          46,
+          60,
+        ],
+        "type": "CallExpression",
+        "typeParameters": Object {
+          "loc": Object {
+            "end": Object {
+              "column": 12,
+              "line": 6,
+            },
+            "start": Object {
+              "column": 9,
+              "line": 6,
+            },
+          },
+          "params": Array [
+            Object {
+              "loc": Object {
+                "end": Object {
+                  "column": 11,
+                  "line": 6,
+                },
+                "start": Object {
+                  "column": 10,
+                  "line": 6,
+                },
+              },
+              "range": Array [
+                56,
+                57,
+              ],
+              "type": "TSTypeReference",
+              "typeName": Object {
+                "loc": Object {
+                  "end": Object {
+                    "column": 11,
+                    "line": 6,
+                  },
+                  "start": Object {
+                    "column": 10,
+                    "line": 6,
+                  },
+                },
+                "name": "d",
+                "range": Array [
+                  56,
+                  57,
+                ],
+                "type": "Identifier",
+              },
+              "typeParameters": undefined,
+            },
+          ],
+          "range": Array [
+            55,
+            58,
+          ],
+          "type": "TSTypeParameterInstantiation",
+        },
+      },
+      "loc": Object {
+        "end": Object {
+          "column": 15,
+          "line": 6,
+        },
+        "start": Object {
+          "column": 0,
+          "line": 6,
+        },
+      },
+      "range": Array [
+        46,
+        61,
+      ],
+      "type": "ExpressionStatement",
+    },
+    Object {
+      "expression": Object {
+        "arguments": Array [],
+        "callee": Object {
+          "expression": Object {
+            "loc": Object {
+              "end": Object {
+                "column": 6,
+                "line": 7,
+              },
+              "start": Object {
+                "column": 5,
+                "line": 7,
+              },
+            },
+            "name": "a",
+            "range": Array [
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+              68,
+            ],
+            "type": "Identifier",
+          },
+          "loc": Object {
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+              "column": 9,
+              "line": 7,
+            },
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+              "line": 7,
+            },
+          },
+          "range": Array [
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+            71,
+          ],
+          "type": "TSInstantiationExpression",
+          "typeParameters": Object {
+            "loc": Object {
+              "end": Object {
+                "column": 9,
+                "line": 7,
+              },
+              "start": Object {
+                "column": 6,
+                "line": 7,
+              },
+            },
+            "params": Array [
+              Object {
+                "loc": Object {
+                  "end": Object {
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+                    "line": 7,
+                  },
+                  "start": Object {
+                    "column": 7,
+                    "line": 7,
+                  },
+                },
+                "range": Array [
+                  69,
+                  70,
+                ],
+                "type": "TSTypeReference",
+                "typeName": Object {
+                  "loc": Object {
+                    "end": Object {
+                      "column": 8,
+                      "line": 7,
+                    },
+                    "start": Object {
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+                      "line": 7,
+                    },
+                  },
+                  "name": "b",
+                  "range": Array [
+                    69,
+                    70,
+                  ],
+                  "type": "Identifier",
+                },
+                "typeParameters": undefined,
+              },
+            ],
+            "range": Array [
+              68,
+              71,
+            ],
+            "type": "TSTypeParameterInstantiation",
+          },
+        },
+        "loc": Object {
+          "end": Object {
+            "column": 15,
+            "line": 7,
+          },
+          "start": Object {
+            "column": 0,
+            "line": 7,
+          },
+        },
+        "range": Array [
+          62,
+          77,
+        ],
+        "type": "NewExpression",
+        "typeParameters": Object {
+          "loc": Object {
+            "end": Object {
+              "column": 13,
+              "line": 7,
+            },
+            "start": Object {
+              "column": 10,
+              "line": 7,
+            },
+          },
+          "params": Array [
+            Object {
+              "loc": Object {
+                "end": Object {
+                  "column": 12,
+                  "line": 7,
+                },
+                "start": Object {
+                  "column": 11,
+                  "line": 7,
+                },
+              },
+              "range": Array [
+                73,
+                74,
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+          "column": 5,
+          "line": 7,
+        },
+      },
+      "range": Array [
+        67,
+        68,
+      ],
+      "type": "Identifier",
+      "value": "a",
+    },
+    Object {
+      "loc": Object {
+        "end": Object {
+          "column": 7,
+          "line": 7,
+        },
+        "start": Object {
+          "column": 6,
+          "line": 7,
+        },
+      },
+      "range": Array [
+        68,
+        69,
+      ],
+      "type": "Punctuator",
+      "value": "<",
+    },
+    Object {
+      "loc": Object {
+        "end": Object {
+          "column": 8,
+          "line": 7,
+        },
+        "start": Object {
+          "column": 7,
+          "line": 7,
+        },
+      },
+      "range": Array [
+        69,
+        70,
+      ],
+      "type": "Identifier",
+      "value": "b",
+    },
+    Object {
+      "loc": Object {
+        "end": Object {
+          "column": 9,
+          "line": 7,
+        },
+        "start": Object {
+          "column": 8,
+          "line": 7,
+        },
+      },
+      "range": Array [
+        70,
+        71,
+      ],
+      "type": "Punctuator",
+      "value": ">",
+    },
+    Object {
+      "loc": Object {
+        "end": Object {
+          "column": 10,
+          "line": 7,
+        },
+        "start": Object {
+          "column": 9,
+          "line": 7,
+        },
+      },
+      "range": Array [
+        71,
+        72,
+      ],
+      "type": "Punctuator",
+      "value": ")",
+    },
+    Object {
+      "loc": Object {
+        "end": Object {
+          "column": 11,
+          "line": 7,
+        },
+        "start": Object {
+          "column": 10,
+          "line": 7,
+        },
+      },
+      "range": Array [
+        72,
+        73,
+      ],
+      "type": "Punctuator",
+      "value": "<",
+    },
+    Object {
+      "loc": Object {
+        "end": Object {
+          "column": 12,
+          "line": 7,
+        },
+        "start": Object {
+          "column": 11,
+          "line": 7,
+        },
+      },
+      "range": Array [
+        73,
+        74,
+      ],
+      "type": "Identifier",
+      "value": "c",
+    },
+    Object {
+      "loc": Object {
+        "end": Object {
+          "column": 13,
+          "line": 7,
+        },
+        "start": Object {
+          "column": 12,
+          "line": 7,
+        },
+      },
+      "range": Array [
+        74,
+        75,
+      ],
+      "type": "Punctuator",
+      "value": ">",
+    },
+    Object {
+      "loc": Object {
+        "end": Object {
+          "column": 14,
+          "line": 7,
+        },
+        "start": Object {
+          "column": 13,
+          "line": 7,
+        },
+      },
+      "range": Array [
+        75,
+        76,
+      ],
+      "type": "Punctuator",
+      "value": "(",
+    },
+    Object {
+      "loc": Object {
+        "end": Object {
+          "column": 15,
+          "line": 7,
+        },
+        "start": Object {
+          "column": 14,
+          "line": 7,
+        },
+      },
+      "range": Array [
+        76,
+        77,
+      ],
+      "type": "Punctuator",
+      "value": ")",
+    },
+    Object {
+      "loc": Object {
+        "end": Object {
+          "column": 16,
+          "line": 7,
+        },
+        "start": Object {
+          "column": 15,
+          "line": 7,
+        },
+      },
+      "range": Array [
+        77,
+        78,
+      ],
+      "type": "Punctuator",
+      "value": ";",
+    },
+  ],
+  "type": "Program",
+}
+`;
diff --git a/packages/typescript-estree/tests/snapshots/typescript/types/conditional-infer-nested.src.ts.shot b/packages/typescript-estree/tests/snapshots/typescript/types/conditional-infer-nested.src.ts.shot
index 50f8f0f7ff82..693f5d114a98 100644
--- a/packages/typescript-estree/tests/snapshots/typescript/types/conditional-infer-nested.src.ts.shot
+++ b/packages/typescript-estree/tests/snapshots/typescript/types/conditional-infer-nested.src.ts.shot
@@ -94,6 +94,7 @@ Object {
             "typeParameter": Object {
               "constraint": undefined,
               "default": undefined,
+              "in": false,
               "loc": Object {
                 "end": Object {
                   "column": 20,
@@ -122,6 +123,7 @@ Object {
                 ],
                 "type": "Identifier",
               },
+              "out": false,
               "range": Array [
                 38,
                 39,
@@ -201,6 +203,7 @@ Object {
             "typeParameter": Object {
               "constraint": undefined,
               "default": undefined,
+              "in": false,
               "loc": Object {
                 "end": Object {
                   "column": 21,
@@ -229,6 +232,7 @@ Object {
                 ],
                 "type": "Identifier",
               },
+              "out": false,
               "range": Array [
                 69,
                 70,
@@ -338,6 +342,7 @@ Object {
                     "typeParameter": Object {
                       "constraint": undefined,
                       "default": undefined,
+                      "in": false,
                       "loc": Object {
                         "end": Object {
                           "column": 31,
@@ -366,6 +371,7 @@ Object {
                         ],
                         "type": "Identifier",
                       },
+                      "out": false,
                       "range": Array [
                         107,
                         108,
@@ -588,6 +594,7 @@ Object {
           Object {
             "constraint": undefined,
             "default": undefined,
+            "in": false,
             "loc": Object {
               "end": Object {
                 "column": 15,
@@ -616,6 +623,7 @@ Object {
               ],
               "type": "Identifier",
             },
+            "out": false,
             "range": Array [
               14,
               15,
diff --git a/packages/typescript-estree/tests/snapshots/typescript/types/conditional-infer-simple.src.ts.shot b/packages/typescript-estree/tests/snapshots/typescript/types/conditional-infer-simple.src.ts.shot
index c172c25e40ad..48cb6977cbf9 100644
--- a/packages/typescript-estree/tests/snapshots/typescript/types/conditional-infer-simple.src.ts.shot
+++ b/packages/typescript-estree/tests/snapshots/typescript/types/conditional-infer-simple.src.ts.shot
@@ -161,6 +161,7 @@ Object {
                   "typeParameter": Object {
                     "constraint": undefined,
                     "default": undefined,
+                    "in": false,
                     "loc": Object {
                       "end": Object {
                         "column": 36,
@@ -189,6 +190,7 @@ Object {
                       ],
                       "type": "Identifier",
                     },
+                    "out": false,
                     "range": Array [
                       35,
                       36,
@@ -273,6 +275,7 @@ Object {
                   "typeParameter": Object {
                     "constraint": undefined,
                     "default": undefined,
+                    "in": false,
                     "loc": Object {
                       "end": Object {
                         "column": 48,
@@ -301,6 +304,7 @@ Object {
                       ],
                       "type": "Identifier",
                     },
+                    "out": false,
                     "range": Array [
                       47,
                       48,
@@ -401,6 +405,7 @@ Object {
           Object {
             "constraint": undefined,
             "default": undefined,
+            "in": false,
             "loc": Object {
               "end": Object {
                 "column": 10,
@@ -429,6 +434,7 @@ Object {
               ],
               "type": "Identifier",
             },
+            "out": false,
             "range": Array [
               9,
               10,
diff --git a/packages/typescript-estree/tests/snapshots/typescript/types/conditional-infer-with-constraint.src.ts.shot b/packages/typescript-estree/tests/snapshots/typescript/types/conditional-infer-with-constraint.src.ts.shot
new file mode 100644
index 000000000000..f4a26f22e90a
--- /dev/null
+++ b/packages/typescript-estree/tests/snapshots/typescript/types/conditional-infer-with-constraint.src.ts.shot
@@ -0,0 +1,4163 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`typescript types conditional-infer-with-constraint.src 1`] = `
+Object {
+  "body": Array [
+    Object {
+      "id": Object {
+        "loc": Object {
+          "end": Object {
+            "column": 7,
+            "line": 1,
+          },
+          "start": Object {
+            "column": 5,
+            "line": 1,
+          },
+        },
+        "name": "X3",
+        "range": Array [
+          5,
+          7,
+        ],
+        "type": "Identifier",
+      },
+      "loc": Object {
+        "end": Object {
+          "column": 74,
+          "line": 1,
+        },
+        "start": Object {
+          "column": 0,
+          "line": 1,
+        },
+      },
+      "range": Array [
+        0,
+        74,
+      ],
+      "type": "TSTypeAliasDeclaration",
+      "typeAnnotation": Object {
+        "checkType": Object {
+          "loc": Object {
+            "end": Object {
+              "column": 14,
+              "line": 1,
+            },
+            "start": Object {
+              "column": 13,
+              "line": 1,
+            },
+          },
+          "range": Array [
+            13,
+            14,
+          ],
+          "type": "TSTypeReference",
+          "typeName": Object {
+            "loc": Object {
+              "end": Object {
+                "column": 14,
+                "line": 1,
+              },
+              "start": Object {
+                "column": 13,
+                "line": 1,
+              },
+            },
+            "name": "T",
+            "range": Array [
+              13,
+              14,
+            ],
+            "type": "Identifier",
+          },
+          "typeParameters": undefined,
+        },
+        "extendsType": Object {
+          "elementTypes": Array [
+            Object {
+              "loc": Object {
+                "end": Object {
+                  "column": 46,
+                  "line": 1,
+                },
+                "start": Object {
+                  "column": 24,
+                  "line": 1,
+                },
+              },
+              "range": Array [
+                24,
+                46,
+              ],
+              "type": "TSInferType",
+              "typeParameter": Object {
+                "constraint": Object {
+                  "loc": Object {
+                    "end": Object {
+                      "column": 46,
+                      "line": 1,
+                    },
+                    "start": Object {
+                      "column": 40,
+                      "line": 1,
+                    },
+                  },
+                  "range": Array [
+                    40,
+                    46,
+                  ],
+                  "type": "TSNumberKeyword",
+                },
+                "default": undefined,
+                "in": false,
+                "loc": Object {
+                  "end": Object {
+                    "column": 46,
+                    "line": 1,
+                  },
+                  "start": Object {
+                    "column": 30,
+                    "line": 1,
+                  },
+                },
+                "name": Object {
+                  "loc": Object {
+                    "end": Object {
+                      "column": 31,
+                      "line": 1,
+                    },
+                    "start": Object {
+                      "column": 30,
+                      "line": 1,
+                    },
+                  },
+                  "name": "U",
+                  "range": Array [
+                    30,
+                    31,
+                  ],
+                  "type": "Identifier",
+                },
+                "out": false,
+                "range": Array [
+                  30,
+                  46,
+                ],
+                "type": "TSTypeParameter",
+              },
+            },
+          ],
+          "loc": Object {
+            "end": Object {
+              "column": 47,
+              "line": 1,
+            },
+            "start": Object {
+              "column": 23,
+              "line": 1,
+            },
+          },
+          "range": Array [
+            23,
+            47,
+          ],
+          "type": "TSTupleType",
+        },
+        "falseType": Object {
+          "loc": Object {
+            "end": Object {
+              "column": 73,
+              "line": 1,
+            },
+            "start": Object {
+              "column": 68,
+              "line": 1,
+            },
+          },
+          "range": Array [
+            68,
+            73,
+          ],
+          "type": "TSNeverKeyword",
+        },
+        "loc": Object {
+          "end": Object {
+            "column": 73,
+            "line": 1,
+          },
+          "start": Object {
+            "column": 13,
+            "line": 1,
+          },
+        },
+        "range": Array [
+          13,
+          73,
+        ],
+        "trueType": Object {
+          "loc": Object {
+            "end": Object {
+              "column": 65,
+              "line": 1,
+            },
+            "start": Object {
+              "column": 50,
+              "line": 1,
+            },
+          },
+          "range": Array [
+            50,
+            65,
+          ],
+          "type": "TSTypeReference",
+          "typeName": Object {
+            "loc": Object {
+              "end": Object {
+                "column": 62,
+                "line": 1,
+              },
+              "start": Object {
+                "column": 50,
+                "line": 1,
+              },
+            },
+            "name": "MustBeNumber",
+            "range": Array [
+              50,
+              62,
+            ],
+            "type": "Identifier",
+          },
+          "typeParameters": Object {
+            "loc": Object {
+              "end": Object {
+                "column": 65,
+                "line": 1,
+              },
+              "start": Object {
+                "column": 62,
+                "line": 1,
+              },
+            },
+            "params": Array [
+              Object {
+                "loc": Object {
+                  "end": Object {
+                    "column": 64,
+                    "line": 1,
+                  },
+                  "start": Object {
+                    "column": 63,
+                    "line": 1,
+                  },
+                },
+                "range": Array [
+                  63,
+                  64,
+                ],
+                "type": "TSTypeReference",
+                "typeName": Object {
+                  "loc": Object {
+                    "end": Object {
+                      "column": 64,
+                      "line": 1,
+                    },
+                    "start": Object {
+                      "column": 63,
+                      "line": 1,
+                    },
+                  },
+                  "name": "U",
+                  "range": Array [
+                    63,
+                    64,
+                  ],
+                  "type": "Identifier",
+                },
+                "typeParameters": undefined,
+              },
+            ],
+            "range": Array [
+              62,
+              65,
+            ],
+            "type": "TSTypeParameterInstantiation",
+          },
+        },
+        "type": "TSConditionalType",
+      },
+      "typeParameters": Object {
+        "loc": Object {
+          "end": Object {
+            "column": 10,
+            "line": 1,
+          },
+          "start": Object {
+            "column": 7,
+            "line": 1,
+          },
+        },
+        "params": Array [
+          Object {
+            "constraint": undefined,
+            "default": undefined,
+            "in": false,
+            "loc": Object {
+              "end": Object {
+                "column": 9,
+                "line": 1,
+              },
+              "start": Object {
+                "column": 8,
+                "line": 1,
+              },
+            },
+            "name": Object {
+              "loc": Object {
+                "end": Object {
+                  "column": 9,
+                  "line": 1,
+                },
+                "start": Object {
+                  "column": 8,
+                  "line": 1,
+                },
+              },
+              "name": "T",
+              "range": Array [
+                8,
+                9,
+              ],
+              "type": "Identifier",
+            },
+            "out": false,
+            "range": Array [
+              8,
+              9,
+            ],
+            "type": "TSTypeParameter",
+          },
+        ],
+        "range": Array [
+          7,
+          10,
+        ],
+        "type": "TSTypeParameterDeclaration",
+      },
+    },
+    Object {
+      "id": Object {
+        "loc": Object {
+          "end": Object {
+            "column": 7,
+            "line": 2,
+          },
+          "start": Object {
+            "column": 5,
+            "line": 2,
+          },
+        },
+        "name": "X4",
+        "range": Array [
+          80,
+          82,
+        ],
+        "type": "Identifier",
+      },
+      "loc": Object {
+        "end": Object {
+          "column": 98,
+          "line": 2,
+        },
+        "start": Object {
+          "column": 0,
+          "line": 2,
+        },
+      },
+      "range": Array [
+        75,
+        173,
+      ],
+      "type": "TSTypeAliasDeclaration",
+      "typeAnnotation": Object {
+        "checkType": Object {
+          "loc": Object {
+            "end": Object {
+              "column": 14,
+              "line": 2,
+            },
+            "start": Object {
+              "column": 13,
+              "line": 2,
+            },
+          },
+          "range": Array [
+            88,
+            89,
+          ],
+          "type": "TSTypeReference",
+          "typeName": Object {
+            "loc": Object {
+              "end": Object {
+                "column": 14,
+                "line": 2,
+              },
+              "start": Object {
+                "column": 13,
+                "line": 2,
+              },
+            },
+            "name": "T",
+            "range": Array [
+              88,
+              89,
+            ],
+            "type": "Identifier",
+          },
+          "typeParameters": undefined,
+        },
+        "extendsType": Object {
+          "elementTypes": Array [
+            Object {
+              "loc": Object {
+                "end": Object {
+                  "column": 46,
+                  "line": 2,
+                },
+                "start": Object {
+                  "column": 24,
+                  "line": 2,
+                },
+              },
+              "range": Array [
+                99,
+                121,
+              ],
+              "type": "TSInferType",
+              "typeParameter": Object {
+                "constraint": Object {
+                  "loc": Object {
+                    "end": Object {
+                      "column": 46,
+                      "line": 2,
+                    },
+                    "start": Object {
+                      "column": 40,
+                      "line": 2,
+                    },
+                  },
+                  "range": Array [
+                    115,
+                    121,
+                  ],
+                  "type": "TSNumberKeyword",
+                },
+                "default": undefined,
+                "in": false,
+                "loc": Object {
+                  "end": Object {
+                    "column": 46,
+                    "line": 2,
+                  },
+                  "start": Object {
+                    "column": 30,
+                    "line": 2,
+                  },
+                },
+                "name": Object {
+                  "loc": Object {
+                    "end": Object {
+                      "column": 31,
+                      "line": 2,
+                    },
+                    "start": Object {
+                      "column": 30,
+                      "line": 2,
+                    },
+                  },
+                  "name": "U",
+                  "range": Array [
+                    105,
+                    106,
+                  ],
+                  "type": "Identifier",
+                },
+                "out": false,
+                "range": Array [
+                  105,
+                  121,
+                ],
+                "type": "TSTypeParameter",
+              },
+            },
+            Object {
+              "loc": Object {
+                "end": Object {
+                  "column": 70,
+                  "line": 2,
+                },
+                "start": Object {
+                  "column": 48,
+                  "line": 2,
+                },
+              },
+              "range": Array [
+                123,
+                145,
+              ],
+              "type": "TSInferType",
+              "typeParameter": Object {
+                "constraint": Object {
+                  "loc": Object {
+                    "end": Object {
+                      "column": 70,
+                      "line": 2,
+                    },
+                    "start": Object {
+                      "column": 64,
+                      "line": 2,
+                    },
+                  },
+                  "range": Array [
+                    139,
+                    145,
+                  ],
+                  "type": "TSNumberKeyword",
+                },
+                "default": undefined,
+                "in": false,
+                "loc": Object {
+                  "end": Object {
+                    "column": 70,
+                    "line": 2,
+                  },
+                  "start": Object {
+                    "column": 54,
+                    "line": 2,
+                  },
+                },
+                "name": Object {
+                  "loc": Object {
+                    "end": Object {
+                      "column": 55,
+                      "line": 2,
+                    },
+                    "start": Object {
+                      "column": 54,
+                      "line": 2,
+                    },
+                  },
+                  "name": "U",
+                  "range": Array [
+                    129,
+                    130,
+                  ],
+                  "type": "Identifier",
+                },
+                "out": false,
+                "range": Array [
+                  129,
+                  145,
+                ],
+                "type": "TSTypeParameter",
+              },
+            },
+          ],
+          "loc": Object {
+            "end": Object {
+              "column": 71,
+              "line": 2,
+            },
+            "start": Object {
+              "column": 23,
+              "line": 2,
+            },
+          },
+          "range": Array [
+            98,
+            146,
+          ],
+          "type": "TSTupleType",
+        },
+        "falseType": Object {
+          "loc": Object {
+            "end": Object {
+              "column": 97,
+              "line": 2,
+            },
+            "start": Object {
+              "column": 92,
+              "line": 2,
+            },
+          },
+          "range": Array [
+            167,
+            172,
+          ],
+          "type": "TSNeverKeyword",
+        },
+        "loc": Object {
+          "end": Object {
+            "column": 97,
+            "line": 2,
+          },
+          "start": Object {
+            "column": 13,
+            "line": 2,
+          },
+        },
+        "range": Array [
+          88,
+          172,
+        ],
+        "trueType": Object {
+          "loc": Object {
+            "end": Object {
+              "column": 89,
+              "line": 2,
+            },
+            "start": Object {
+              "column": 74,
+              "line": 2,
+            },
+          },
+          "range": Array [
+            149,
+            164,
+          ],
+          "type": "TSTypeReference",
+          "typeName": Object {
+            "loc": Object {
+              "end": Object {
+                "column": 86,
+                "line": 2,
+              },
+              "start": Object {
+                "column": 74,
+                "line": 2,
+              },
+            },
+            "name": "MustBeNumber",
+            "range": Array [
+              149,
+              161,
+            ],
+            "type": "Identifier",
+          },
+          "typeParameters": Object {
+            "loc": Object {
+              "end": Object {
+                "column": 89,
+                "line": 2,
+              },
+              "start": Object {
+                "column": 86,
+                "line": 2,
+              },
+            },
+            "params": Array [
+              Object {
+                "loc": Object {
+                  "end": Object {
+                    "column": 88,
+                    "line": 2,
+                  },
+                  "start": Object {
+                    "column": 87,
+                    "line": 2,
+                  },
+                },
+                "range": Array [
+                  162,
+                  163,
+                ],
+                "type": "TSTypeReference",
+                "typeName": Object {
+                  "loc": Object {
+                    "end": Object {
+                      "column": 88,
+                      "line": 2,
+                    },
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+        "start": Object {
+          "column": 24,
+          "line": 5,
+        },
+      },
+      "range": Array [
+        366,
+        371,
+      ],
+      "type": "Identifier",
+      "value": "infer",
+    },
+    Object {
+      "loc": Object {
+        "end": Object {
+          "column": 31,
+          "line": 5,
+        },
+        "start": Object {
+          "column": 30,
+          "line": 5,
+        },
+      },
+      "range": Array [
+        372,
+        373,
+      ],
+      "type": "Identifier",
+      "value": "U",
+    },
+    Object {
+      "loc": Object {
+        "end": Object {
+          "column": 39,
+          "line": 5,
+        },
+        "start": Object {
+          "column": 32,
+          "line": 5,
+        },
+      },
+      "range": Array [
+        374,
+        381,
+      ],
+      "type": "Keyword",
+      "value": "extends",
+    },
+    Object {
+      "loc": Object {
+        "end": Object {
+          "column": 46,
+          "line": 5,
+        },
+        "start": Object {
+          "column": 40,
+          "line": 5,
+        },
+      },
+      "range": Array [
+        382,
+        388,
+      ],
+      "type": "Identifier",
+      "value": "string",
+    },
+    Object {
+      "loc": Object {
+        "end": Object {
+          "column": 47,
+          "line": 5,
+        },
+        "start": Object {
+          "column": 46,
+          "line": 5,
+        },
+      },
+      "range": Array [
+        388,
+        389,
+      ],
+      "type": "Punctuator",
+      "value": ",",
+    },
+    Object {
+      "loc": Object {
+        "end": Object {
+          "column": 53,
+          "line": 5,
+        },
+        "start": Object {
+          "column": 48,
+          "line": 5,
+        },
+      },
+      "range": Array [
+        390,
+        395,
+      ],
+      "type": "Identifier",
+      "value": "infer",
+    },
+    Object {
+      "loc": Object {
+        "end": Object {
+          "column": 55,
+          "line": 5,
+        },
+        "start": Object {
+          "column": 54,
+          "line": 5,
+        },
+      },
+      "range": Array [
+        396,
+        397,
+      ],
+      "type": "Identifier",
+      "value": "U",
+    },
+    Object {
+      "loc": Object {
+        "end": Object {
+          "column": 63,
+          "line": 5,
+        },
+        "start": Object {
+          "column": 56,
+          "line": 5,
+        },
+      },
+      "range": Array [
+        398,
+        405,
+      ],
+      "type": "Keyword",
+      "value": "extends",
+    },
+    Object {
+      "loc": Object {
+        "end": Object {
+          "column": 70,
+          "line": 5,
+        },
+        "start": Object {
+          "column": 64,
+          "line": 5,
+        },
+      },
+      "range": Array [
+        406,
+        412,
+      ],
+      "type": "Identifier",
+      "value": "number",
+    },
+    Object {
+      "loc": Object {
+        "end": Object {
+          "column": 71,
+          "line": 5,
+        },
+        "start": Object {
+          "column": 70,
+          "line": 5,
+        },
+      },
+      "range": Array [
+        412,
+        413,
+      ],
+      "type": "Punctuator",
+      "value": "]",
+    },
+    Object {
+      "loc": Object {
+        "end": Object {
+          "column": 73,
+          "line": 5,
+        },
+        "start": Object {
+          "column": 72,
+          "line": 5,
+        },
+      },
+      "range": Array [
+        414,
+        415,
+      ],
+      "type": "Punctuator",
+      "value": "?",
+    },
+    Object {
+      "loc": Object {
+        "end": Object {
+          "column": 75,
+          "line": 5,
+        },
+        "start": Object {
+          "column": 74,
+          "line": 5,
+        },
+      },
+      "range": Array [
+        416,
+        417,
+      ],
+      "type": "Identifier",
+      "value": "U",
+    },
+    Object {
+      "loc": Object {
+        "end": Object {
+          "column": 77,
+          "line": 5,
+        },
+        "start": Object {
+          "column": 76,
+          "line": 5,
+        },
+      },
+      "range": Array [
+        418,
+        419,
+      ],
+      "type": "Punctuator",
+      "value": ":",
+    },
+    Object {
+      "loc": Object {
+        "end": Object {
+          "column": 83,
+          "line": 5,
+        },
+        "start": Object {
+          "column": 78,
+          "line": 5,
+        },
+      },
+      "range": Array [
+        420,
+        425,
+      ],
+      "type": "Identifier",
+      "value": "never",
+    },
+    Object {
+      "loc": Object {
+        "end": Object {
+          "column": 84,
+          "line": 5,
+        },
+        "start": Object {
+          "column": 83,
+          "line": 5,
+        },
+      },
+      "range": Array [
+        425,
+        426,
+      ],
+      "type": "Punctuator",
+      "value": ";",
+    },
+  ],
+  "type": "Program",
+}
+`;
diff --git a/packages/typescript-estree/tests/snapshots/typescript/types/conditional-infer.src.ts.shot b/packages/typescript-estree/tests/snapshots/typescript/types/conditional-infer.src.ts.shot
index d55b6ac728e0..9534b875bd9b 100644
--- a/packages/typescript-estree/tests/snapshots/typescript/types/conditional-infer.src.ts.shot
+++ b/packages/typescript-estree/tests/snapshots/typescript/types/conditional-infer.src.ts.shot
@@ -94,6 +94,7 @@ Object {
             "typeParameter": Object {
               "constraint": undefined,
               "default": undefined,
+              "in": false,
               "loc": Object {
                 "end": Object {
                   "column": 36,
@@ -122,6 +123,7 @@ Object {
                 ],
                 "type": "Identifier",
               },
+              "out": false,
               "range": Array [
                 35,
                 36,
@@ -248,6 +250,7 @@ Object {
           Object {
             "constraint": undefined,
             "default": undefined,
+            "in": false,
             "loc": Object {
               "end": Object {
                 "column": 14,
@@ -276,6 +279,7 @@ Object {
               ],
               "type": "Identifier",
             },
+            "out": false,
             "range": Array [
               13,
               14,
diff --git a/packages/typescript-estree/tests/snapshots/typescript/types/constructor-generic.src.ts.shot b/packages/typescript-estree/tests/snapshots/typescript/types/constructor-generic.src.ts.shot
index d0434a7edb77..43b72d5dff0f 100644
--- a/packages/typescript-estree/tests/snapshots/typescript/types/constructor-generic.src.ts.shot
+++ b/packages/typescript-estree/tests/snapshots/typescript/types/constructor-generic.src.ts.shot
@@ -197,6 +197,7 @@ Object {
                     Object {
                       "constraint": undefined,
                       "default": undefined,
+                      "in": false,
                       "loc": Object {
                         "end": Object {
                           "column": 13,
@@ -225,6 +226,7 @@ Object {
                         ],
                         "type": "Identifier",
                       },
+                      "out": false,
                       "range": Array [
                         12,
                         13,
diff --git a/packages/typescript-estree/tests/snapshots/typescript/types/function-generic.src.ts.shot b/packages/typescript-estree/tests/snapshots/typescript/types/function-generic.src.ts.shot
index 20329d59abb4..3d0a92854878 100644
--- a/packages/typescript-estree/tests/snapshots/typescript/types/function-generic.src.ts.shot
+++ b/packages/typescript-estree/tests/snapshots/typescript/types/function-generic.src.ts.shot
@@ -196,6 +196,7 @@ Object {
                     Object {
                       "constraint": undefined,
                       "default": undefined,
+                      "in": false,
                       "loc": Object {
                         "end": Object {
                           "column": 9,
@@ -224,6 +225,7 @@ Object {
                         ],
                         "type": "Identifier",
                       },
+                      "out": false,
                       "range": Array [
                         8,
                         9,
diff --git a/packages/typescript-estree/tests/snapshots/typescript/types/intersection-type.src.ts.shot b/packages/typescript-estree/tests/snapshots/typescript/types/intersection-type.src.ts.shot
index de61acf25c46..7e56c87cf8bc 100644
--- a/packages/typescript-estree/tests/snapshots/typescript/types/intersection-type.src.ts.shot
+++ b/packages/typescript-estree/tests/snapshots/typescript/types/intersection-type.src.ts.shot
@@ -274,6 +274,7 @@ Object {
           Object {
             "constraint": undefined,
             "default": undefined,
+            "in": false,
             "loc": Object {
               "end": Object {
                 "column": 17,
@@ -302,6 +303,7 @@ Object {
               ],
               "type": "Identifier",
             },
+            "out": false,
             "range": Array [
               16,
               17,
diff --git a/packages/typescript-estree/tests/snapshots/typescript/types/mapped-named-type.src.ts.shot b/packages/typescript-estree/tests/snapshots/typescript/types/mapped-named-type.src.ts.shot
index 4adec74e80a9..ad9603c0953a 100644
--- a/packages/typescript-estree/tests/snapshots/typescript/types/mapped-named-type.src.ts.shot
+++ b/packages/typescript-estree/tests/snapshots/typescript/types/mapped-named-type.src.ts.shot
@@ -234,6 +234,7 @@ Object {
             },
           },
           "default": undefined,
+          "in": false,
           "loc": Object {
             "end": Object {
               "column": 15,
@@ -262,6 +263,7 @@ Object {
             ],
             "type": "Identifier",
           },
+          "out": false,
           "range": Array [
             20,
             32,
@@ -284,6 +286,7 @@ Object {
           Object {
             "constraint": undefined,
             "default": undefined,
+            "in": false,
             "loc": Object {
               "end": Object {
                 "column": 11,
@@ -312,6 +315,7 @@ Object {
               ],
               "type": "Identifier",
             },
+            "out": false,
             "range": Array [
               10,
               11,
diff --git a/packages/typescript-estree/tests/snapshots/typescript/types/mapped-readonly-minus.src.ts.shot b/packages/typescript-estree/tests/snapshots/typescript/types/mapped-readonly-minus.src.ts.shot
index 5bc1ed74e225..b4f571e2c118 100644
--- a/packages/typescript-estree/tests/snapshots/typescript/types/mapped-readonly-minus.src.ts.shot
+++ b/packages/typescript-estree/tests/snapshots/typescript/types/mapped-readonly-minus.src.ts.shot
@@ -94,6 +94,7 @@ Object {
                     "type": "TSStringKeyword",
                   },
                   "default": undefined,
+                  "in": false,
                   "loc": Object {
                     "end": Object {
                       "column": 33,
@@ -122,6 +123,7 @@ Object {
                     ],
                     "type": "Identifier",
                   },
+                  "out": false,
                   "range": Array [
                     22,
                     33,
diff --git a/packages/typescript-estree/tests/snapshots/typescript/types/mapped-readonly-plus.src.ts.shot b/packages/typescript-estree/tests/snapshots/typescript/types/mapped-readonly-plus.src.ts.shot
index 0529961e6651..f3ba73b4aa51 100644
--- a/packages/typescript-estree/tests/snapshots/typescript/types/mapped-readonly-plus.src.ts.shot
+++ b/packages/typescript-estree/tests/snapshots/typescript/types/mapped-readonly-plus.src.ts.shot
@@ -94,6 +94,7 @@ Object {
                     "type": "TSStringKeyword",
                   },
                   "default": undefined,
+                  "in": false,
                   "loc": Object {
                     "end": Object {
                       "column": 33,
@@ -122,6 +123,7 @@ Object {
                     ],
                     "type": "Identifier",
                   },
+                  "out": false,
                   "range": Array [
                     22,
                     33,
diff --git a/packages/typescript-estree/tests/snapshots/typescript/types/mapped-readonly.src.ts.shot b/packages/typescript-estree/tests/snapshots/typescript/types/mapped-readonly.src.ts.shot
index b18350797d01..cce96c961cc5 100644
--- a/packages/typescript-estree/tests/snapshots/typescript/types/mapped-readonly.src.ts.shot
+++ b/packages/typescript-estree/tests/snapshots/typescript/types/mapped-readonly.src.ts.shot
@@ -94,6 +94,7 @@ Object {
                     "type": "TSStringKeyword",
                   },
                   "default": undefined,
+                  "in": false,
                   "loc": Object {
                     "end": Object {
                       "column": 32,
@@ -122,6 +123,7 @@ Object {
                     ],
                     "type": "Identifier",
                   },
+                  "out": false,
                   "range": Array [
                     21,
                     32,
diff --git a/packages/typescript-estree/tests/snapshots/typescript/types/mapped-untypped.src.ts.shot b/packages/typescript-estree/tests/snapshots/typescript/types/mapped-untypped.src.ts.shot
index d254c7d59336..27b7b9c9c4d9 100644
--- a/packages/typescript-estree/tests/snapshots/typescript/types/mapped-untypped.src.ts.shot
+++ b/packages/typescript-estree/tests/snapshots/typescript/types/mapped-untypped.src.ts.shot
@@ -75,6 +75,7 @@ Object {
                     "type": "TSStringKeyword",
                   },
                   "default": undefined,
+                  "in": false,
                   "loc": Object {
                     "end": Object {
                       "column": 23,
@@ -103,6 +104,7 @@ Object {
                     ],
                     "type": "Identifier",
                   },
+                  "out": false,
                   "range": Array [
                     12,
                     23,
diff --git a/packages/typescript-estree/tests/snapshots/typescript/types/mapped.src.ts.shot b/packages/typescript-estree/tests/snapshots/typescript/types/mapped.src.ts.shot
index 75f22d34e024..1689f5647b9f 100644
--- a/packages/typescript-estree/tests/snapshots/typescript/types/mapped.src.ts.shot
+++ b/packages/typescript-estree/tests/snapshots/typescript/types/mapped.src.ts.shot
@@ -92,6 +92,7 @@ Object {
                     "type": "TSStringKeyword",
                   },
                   "default": undefined,
+                  "in": false,
                   "loc": Object {
                     "end": Object {
                       "column": 23,
@@ -120,6 +121,7 @@ Object {
                     ],
                     "type": "Identifier",
                   },
+                  "out": false,
                   "range": Array [
                     12,
                     23,
diff --git a/packages/typescript-estree/tests/snapshots/typescript/types/optional-variance-in-and-out.src.ts.shot b/packages/typescript-estree/tests/snapshots/typescript/types/optional-variance-in-and-out.src.ts.shot
new file mode 100644
index 000000000000..26e233652d4c
--- /dev/null
+++ b/packages/typescript-estree/tests/snapshots/typescript/types/optional-variance-in-and-out.src.ts.shot
@@ -0,0 +1,626 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`typescript types optional-variance-in-and-out.src 1`] = `
+Object {
+  "body": Array [
+    Object {
+      "id": Object {
+        "loc": Object {
+          "end": Object {
+            "column": 11,
+            "line": 1,
+          },
+          "start": Object {
+            "column": 5,
+            "line": 1,
+          },
+        },
+        "name": "Mapper",
+        "range": Array [
+          5,
+          11,
+        ],
+        "type": "Identifier",
+      },
+      "loc": Object {
+        "end": Object {
+          "column": 39,
+          "line": 1,
+        },
+        "start": Object {
+          "column": 0,
+          "line": 1,
+        },
+      },
+      "range": Array [
+        0,
+        39,
+      ],
+      "type": "TSTypeAliasDeclaration",
+      "typeAnnotation": Object {
+        "loc": Object {
+          "end": Object {
+            "column": 38,
+            "line": 1,
+          },
+          "start": Object {
+            "column": 27,
+            "line": 1,
+          },
+        },
+        "params": Array [
+          Object {
+            "loc": Object {
+              "end": Object {
+                "column": 32,
+                "line": 1,
+              },
+              "start": Object {
+                "column": 28,
+                "line": 1,
+              },
+            },
+            "name": "x",
+            "range": Array [
+              28,
+              32,
+            ],
+            "type": "Identifier",
+            "typeAnnotation": Object {
+              "loc": Object {
+                "end": Object {
+                  "column": 32,
+                  "line": 1,
+                },
+                "start": Object {
+                  "column": 29,
+                  "line": 1,
+                },
+              },
+              "range": Array [
+                29,
+                32,
+              ],
+              "type": "TSTypeAnnotation",
+              "typeAnnotation": Object {
+                "loc": Object {
+                  "end": Object {
+                    "column": 32,
+                    "line": 1,
+                  },
+                  "start": Object {
+                    "column": 31,
+                    "line": 1,
+                  },
+                },
+                "range": Array [
+                  31,
+                  32,
+                ],
+                "type": "TSTypeReference",
+                "typeName": Object {
+                  "loc": Object {
+                    "end": Object {
+                      "column": 32,
+                      "line": 1,
+                    },
+                    "start": Object {
+                      "column": 31,
+                      "line": 1,
+                    },
+                  },
+                  "name": "T",
+                  "range": Array [
+                    31,
+                    32,
+                  ],
+                  "type": "Identifier",
+                },
+                "typeParameters": undefined,
+              },
+            },
+          },
+        ],
+        "range": Array [
+          27,
+          38,
+        ],
+        "returnType": Object {
+          "loc": Object {
+            "end": Object {
+              "column": 38,
+              "line": 1,
+            },
+            "start": Object {
+              "column": 34,
+              "line": 1,
+            },
+          },
+          "range": Array [
+            34,
+            38,
+          ],
+          "type": "TSTypeAnnotation",
+          "typeAnnotation": Object {
+            "loc": Object {
+              "end": Object {
+                "column": 38,
+                "line": 1,
+              },
+              "start": Object {
+                "column": 37,
+                "line": 1,
+              },
+            },
+            "range": Array [
+              37,
+              38,
+            ],
+            "type": "TSTypeReference",
+            "typeName": Object {
+              "loc": Object {
+                "end": Object {
+                  "column": 38,
+                  "line": 1,
+                },
+                "start": Object {
+                  "column": 37,
+                  "line": 1,
+                },
+              },
+              "name": "U",
+              "range": Array [
+                37,
+                38,
+              ],
+              "type": "Identifier",
+            },
+            "typeParameters": undefined,
+          },
+        },
+        "type": "TSFunctionType",
+      },
+      "typeParameters": Object {
+        "loc": Object {
+          "end": Object {
+            "column": 24,
+            "line": 1,
+          },
+          "start": Object {
+            "column": 11,
+            "line": 1,
+          },
+        },
+        "params": Array [
+          Object {
+            "constraint": undefined,
+            "default": undefined,
+            "in": true,
+            "loc": Object {
+              "end": Object {
+                "column": 16,
+                "line": 1,
+              },
+              "start": Object {
+                "column": 12,
+                "line": 1,
+              },
+            },
+            "name": Object {
+              "loc": Object {
+                "end": Object {
+                  "column": 16,
+                  "line": 1,
+                },
+                "start": Object {
+                  "column": 15,
+                  "line": 1,
+                },
+              },
+              "name": "T",
+              "range": Array [
+                15,
+                16,
+              ],
+              "type": "Identifier",
+            },
+            "out": false,
+            "range": Array [
+              12,
+              16,
+            ],
+            "type": "TSTypeParameter",
+          },
+          Object {
+            "constraint": undefined,
+            "default": undefined,
+            "in": false,
+            "loc": Object {
+              "end": Object {
+                "column": 23,
+                "line": 1,
+              },
+              "start": Object {
+                "column": 18,
+                "line": 1,
+              },
+            },
+            "name": Object {
+              "loc": Object {
+                "end": Object {
+                  "column": 23,
+                  "line": 1,
+                },
+                "start": Object {
+                  "column": 22,
+                  "line": 1,
+                },
+              },
+              "name": "U",
+              "range": Array [
+                22,
+                23,
+              ],
+              "type": "Identifier",
+            },
+            "out": true,
+            "range": Array [
+              18,
+              23,
+            ],
+            "type": "TSTypeParameter",
+          },
+        ],
+        "range": Array [
+          11,
+          24,
+        ],
+        "type": "TSTypeParameterDeclaration",
+      },
+    },
+  ],
+  "comments": Array [],
+  "loc": Object {
+    "end": Object {
+      "column": 0,
+      "line": 2,
+    },
+    "start": Object {
+      "column": 0,
+      "line": 1,
+    },
+  },
+  "range": Array [
+    0,
+    40,
+  ],
+  "sourceType": "script",
+  "tokens": Array [
+    Object {
+      "loc": Object {
+        "end": Object {
+          "column": 4,
+          "line": 1,
+        },
+        "start": Object {
+          "column": 0,
+          "line": 1,
+        },
+      },
+      "range": Array [
+        0,
+        4,
+      ],
+      "type": "Identifier",
+      "value": "type",
+    },
+    Object {
+      "loc": Object {
+        "end": Object {
+          "column": 11,
+          "line": 1,
+        },
+        "start": Object {
+          "column": 5,
+          "line": 1,
+        },
+      },
+      "range": Array [
+        5,
+        11,
+      ],
+      "type": "Identifier",
+      "value": "Mapper",
+    },
+    Object {
+      "loc": Object {
+        "end": Object {
+          "column": 12,
+          "line": 1,
+        },
+        "start": Object {
+          "column": 11,
+          "line": 1,
+        },
+      },
+      "range": Array [
+        11,
+        12,
+      ],
+      "type": "Punctuator",
+      "value": "<",
+    },
+    Object {
+      "loc": Object {
+        "end": Object {
+          "column": 14,
+          "line": 1,
+        },
+        "start": Object {
+          "column": 12,
+          "line": 1,
+        },
+      },
+      "range": Array [
+        12,
+        14,
+      ],
+      "type": "Keyword",
+      "value": "in",
+    },
+    Object {
+      "loc": Object {
+        "end": Object {
+          "column": 16,
+          "line": 1,
+        },
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diff --git a/packages/typescript-estree/tests/snapshots/typescript/types/optional-variance-in-out.src.ts.shot b/packages/typescript-estree/tests/snapshots/typescript/types/optional-variance-in-out.src.ts.shot
new file mode 100644
index 000000000000..9639322188cd
--- /dev/null
+++ b/packages/typescript-estree/tests/snapshots/typescript/types/optional-variance-in-out.src.ts.shot
@@ -0,0 +1,551 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`typescript types optional-variance-in-out.src 1`] = `
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diff --git a/packages/typescript-estree/tests/snapshots/typescript/types/optional-variance-in.src.ts.shot b/packages/typescript-estree/tests/snapshots/typescript/types/optional-variance-in.src.ts.shot
new file mode 100644
index 000000000000..bf2e85f702ff
--- /dev/null
+++ b/packages/typescript-estree/tests/snapshots/typescript/types/optional-variance-in.src.ts.shot
@@ -0,0 +1,514 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`typescript types optional-variance-in.src 1`] = `
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+    "end": Object {
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+      "line": 2,
+    },
+    "start": Object {
+      "column": 0,
+      "line": 1,
+    },
+  },
+  "range": Array [
+    0,
+    38,
+  ],
+  "sourceType": "script",
+  "tokens": Array [
+    Object {
+      "loc": Object {
+        "end": Object {
+          "column": 4,
+          "line": 1,
+        },
+        "start": Object {
+          "column": 0,
+          "line": 1,
+        },
+      },
+      "range": Array [
+        0,
+        4,
+      ],
+      "type": "Identifier",
+      "value": "type",
+    },
+    Object {
+      "loc": Object {
+        "end": Object {
+          "column": 13,
+          "line": 1,
+        },
+        "start": Object {
+          "column": 5,
+          "line": 1,
+        },
+      },
+      "range": Array [
+        5,
+        13,
+      ],
+      "type": "Identifier",
+      "value": "Consumer",
+    },
+    Object {
+      "loc": Object {
+        "end": Object {
+          "column": 14,
+          "line": 1,
+        },
+        "start": Object {
+          "column": 13,
+          "line": 1,
+        },
+      },
+      "range": Array [
+        13,
+        14,
+      ],
+      "type": "Punctuator",
+      "value": "<",
+    },
+    Object {
+      "loc": Object {
+        "end": Object {
+          "column": 16,
+          "line": 1,
+        },
+        "start": Object {
+          "column": 14,
+          "line": 1,
+        },
+      },
+      "range": Array [
+        14,
+        16,
+      ],
+      "type": "Keyword",
+      "value": "in",
+    },
+    Object {
+      "loc": Object {
+        "end": Object {
+          "column": 18,
+          "line": 1,
+        },
+        "start": Object {
+          "column": 17,
+          "line": 1,
+        },
+      },
+      "range": Array [
+        17,
+        18,
+      ],
+      "type": "Identifier",
+      "value": "T",
+    },
+    Object {
+      "loc": Object {
+        "end": Object {
+          "column": 19,
+          "line": 1,
+        },
+        "start": Object {
+          "column": 18,
+          "line": 1,
+        },
+      },
+      "range": Array [
+        18,
+        19,
+      ],
+      "type": "Punctuator",
+      "value": ">",
+    },
+    Object {
+      "loc": Object {
+        "end": Object {
+          "column": 21,
+          "line": 1,
+        },
+        "start": Object {
+          "column": 20,
+          "line": 1,
+        },
+      },
+      "range": Array [
+        20,
+        21,
+      ],
+      "type": "Punctuator",
+      "value": "=",
+    },
+    Object {
+      "loc": Object {
+        "end": Object {
+          "column": 23,
+          "line": 1,
+        },
+        "start": Object {
+          "column": 22,
+          "line": 1,
+        },
+      },
+      "range": Array [
+        22,
+        23,
+      ],
+      "type": "Punctuator",
+      "value": "(",
+    },
+    Object {
+      "loc": Object {
+        "end": Object {
+          "column": 24,
+          "line": 1,
+        },
+        "start": Object {
+          "column": 23,
+          "line": 1,
+        },
+      },
+      "range": Array [
+        23,
+        24,
+      ],
+      "type": "Identifier",
+      "value": "x",
+    },
+    Object {
+      "loc": Object {
+        "end": Object {
+          "column": 25,
+          "line": 1,
+        },
+        "start": Object {
+          "column": 24,
+          "line": 1,
+        },
+      },
+      "range": Array [
+        24,
+        25,
+      ],
+      "type": "Punctuator",
+      "value": ":",
+    },
+    Object {
+      "loc": Object {
+        "end": Object {
+          "column": 27,
+          "line": 1,
+        },
+        "start": Object {
+          "column": 26,
+          "line": 1,
+        },
+      },
+      "range": Array [
+        26,
+        27,
+      ],
+      "type": "Identifier",
+      "value": "T",
+    },
+    Object {
+      "loc": Object {
+        "end": Object {
+          "column": 28,
+          "line": 1,
+        },
+        "start": Object {
+          "column": 27,
+          "line": 1,
+        },
+      },
+      "range": Array [
+        27,
+        28,
+      ],
+      "type": "Punctuator",
+      "value": ")",
+    },
+    Object {
+      "loc": Object {
+        "end": Object {
+          "column": 31,
+          "line": 1,
+        },
+        "start": Object {
+          "column": 29,
+          "line": 1,
+        },
+      },
+      "range": Array [
+        29,
+        31,
+      ],
+      "type": "Punctuator",
+      "value": "=>",
+    },
+    Object {
+      "loc": Object {
+        "end": Object {
+          "column": 36,
+          "line": 1,
+        },
+        "start": Object {
+          "column": 32,
+          "line": 1,
+        },
+      },
+      "range": Array [
+        32,
+        36,
+      ],
+      "type": "Keyword",
+      "value": "void",
+    },
+    Object {
+      "loc": Object {
+        "end": Object {
+          "column": 37,
+          "line": 1,
+        },
+        "start": Object {
+          "column": 36,
+          "line": 1,
+        },
+      },
+      "range": Array [
+        36,
+        37,
+      ],
+      "type": "Punctuator",
+      "value": ";",
+    },
+  ],
+  "type": "Program",
+}
+`;
diff --git a/packages/typescript-estree/tests/snapshots/typescript/types/optional-variance-out.src.ts.shot b/packages/typescript-estree/tests/snapshots/typescript/types/optional-variance-out.src.ts.shot
new file mode 100644
index 000000000000..04c6769229f4
--- /dev/null
+++ b/packages/typescript-estree/tests/snapshots/typescript/types/optional-variance-out.src.ts.shot
@@ -0,0 +1,407 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`typescript types optional-variance-out.src 1`] = `
+Object {
+  "body": Array [
+    Object {
+      "id": Object {
+        "loc": Object {
+          "end": Object {
+            "column": 13,
+            "line": 1,
+          },
+          "start": Object {
+            "column": 5,
+            "line": 1,
+          },
+        },
+        "name": "Provider",
+        "range": Array [
+          5,
+          13,
+        ],
+        "type": "Identifier",
+      },
+      "loc": Object {
+        "end": Object {
+          "column": 31,
+          "line": 1,
+        },
+        "start": Object {
+          "column": 0,
+          "line": 1,
+        },
+      },
+      "range": Array [
+        0,
+        31,
+      ],
+      "type": "TSTypeAliasDeclaration",
+      "typeAnnotation": Object {
+        "loc": Object {
+          "end": Object {
+            "column": 30,
+            "line": 1,
+          },
+          "start": Object {
+            "column": 23,
+            "line": 1,
+          },
+        },
+        "params": Array [],
+        "range": Array [
+          23,
+          30,
+        ],
+        "returnType": Object {
+          "loc": Object {
+            "end": Object {
+              "column": 30,
+              "line": 1,
+            },
+            "start": Object {
+              "column": 26,
+              "line": 1,
+            },
+          },
+          "range": Array [
+            26,
+            30,
+          ],
+          "type": "TSTypeAnnotation",
+          "typeAnnotation": Object {
+            "loc": Object {
+              "end": Object {
+                "column": 30,
+                "line": 1,
+              },
+              "start": Object {
+                "column": 29,
+                "line": 1,
+              },
+            },
+            "range": Array [
+              29,
+              30,
+            ],
+            "type": "TSTypeReference",
+            "typeName": Object {
+              "loc": Object {
+                "end": Object {
+                  "column": 30,
+                  "line": 1,
+                },
+                "start": Object {
+                  "column": 29,
+                  "line": 1,
+                },
+              },
+              "name": "T",
+              "range": Array [
+                29,
+                30,
+              ],
+              "type": "Identifier",
+            },
+            "typeParameters": undefined,
+          },
+        },
+        "type": "TSFunctionType",
+      },
+      "typeParameters": Object {
+        "loc": Object {
+          "end": Object {
+            "column": 20,
+            "line": 1,
+          },
+          "start": Object {
+            "column": 13,
+            "line": 1,
+          },
+        },
+        "params": Array [
+          Object {
+            "constraint": undefined,
+            "default": undefined,
+            "in": false,
+            "loc": Object {
+              "end": Object {
+                "column": 19,
+                "line": 1,
+              },
+              "start": Object {
+                "column": 14,
+                "line": 1,
+              },
+            },
+            "name": Object {
+              "loc": Object {
+                "end": Object {
+                  "column": 19,
+                  "line": 1,
+                },
+                "start": Object {
+                  "column": 18,
+                  "line": 1,
+                },
+              },
+              "name": "T",
+              "range": Array [
+                18,
+                19,
+              ],
+              "type": "Identifier",
+            },
+            "out": true,
+            "range": Array [
+              14,
+              19,
+            ],
+            "type": "TSTypeParameter",
+          },
+        ],
+        "range": Array [
+          13,
+          20,
+        ],
+        "type": "TSTypeParameterDeclaration",
+      },
+    },
+  ],
+  "comments": Array [],
+  "loc": Object {
+    "end": Object {
+      "column": 0,
+      "line": 2,
+    },
+    "start": Object {
+      "column": 0,
+      "line": 1,
+    },
+  },
+  "range": Array [
+    0,
+    32,
+  ],
+  "sourceType": "script",
+  "tokens": Array [
+    Object {
+      "loc": Object {
+        "end": Object {
+          "column": 4,
+          "line": 1,
+        },
+        "start": Object {
+          "column": 0,
+          "line": 1,
+        },
+      },
+      "range": Array [
+        0,
+        4,
+      ],
+      "type": "Identifier",
+      "value": "type",
+    },
+    Object {
+      "loc": Object {
+        "end": Object {
+          "column": 13,
+          "line": 1,
+        },
+        "start": Object {
+          "column": 5,
+          "line": 1,
+        },
+      },
+      "range": Array [
+        5,
+        13,
+      ],
+      "type": "Identifier",
+      "value": "Provider",
+    },
+    Object {
+      "loc": Object {
+        "end": Object {
+          "column": 14,
+          "line": 1,
+        },
+        "start": Object {
+          "column": 13,
+          "line": 1,
+        },
+      },
+      "range": Array [
+        13,
+        14,
+      ],
+      "type": "Punctuator",
+      "value": "<",
+    },
+    Object {
+      "loc": Object {
+        "end": Object {
+          "column": 17,
+          "line": 1,
+        },
+        "start": Object {
+          "column": 14,
+          "line": 1,
+        },
+      },
+      "range": Array [
+        14,
+        17,
+      ],
+      "type": "Identifier",
+      "value": "out",
+    },
+    Object {
+      "loc": Object {
+        "end": Object {
+          "column": 19,
+          "line": 1,
+        },
+        "start": Object {
+          "column": 18,
+          "line": 1,
+        },
+      },
+      "range": Array [
+        18,
+        19,
+      ],
+      "type": "Identifier",
+      "value": "T",
+    },
+    Object {
+      "loc": Object {
+        "end": Object {
+          "column": 20,
+          "line": 1,
+        },
+        "start": Object {
+          "column": 19,
+          "line": 1,
+        },
+      },
+      "range": Array [
+        19,
+        20,
+      ],
+      "type": "Punctuator",
+      "value": ">",
+    },
+    Object {
+      "loc": Object {
+        "end": Object {
+          "column": 22,
+          "line": 1,
+        },
+        "start": Object {
+          "column": 21,
+          "line": 1,
+        },
+      },
+      "range": Array [
+        21,
+        22,
+      ],
+      "type": "Punctuator",
+      "value": "=",
+    },
+    Object {
+      "loc": Object {
+        "end": Object {
+          "column": 24,
+          "line": 1,
+        },
+        "start": Object {
+          "column": 23,
+          "line": 1,
+        },
+      },
+      "range": Array [
+        23,
+        24,
+      ],
+      "type": "Punctuator",
+      "value": "(",
+    },
+    Object {
+      "loc": Object {
+        "end": Object {
+          "column": 25,
+          "line": 1,
+        },
+        "start": Object {
+          "column": 24,
+          "line": 1,
+        },
+      },
+      "range": Array [
+        24,
+        25,
+      ],
+      "type": "Punctuator",
+      "value": ")",
+    },
+    Object {
+      "loc": Object {
+        "end": Object {
+          "column": 28,
+          "line": 1,
+        },
+        "start": Object {
+          "column": 26,
+          "line": 1,
+        },
+      },
+      "range": Array [
+        26,
+        28,
+      ],
+      "type": "Punctuator",
+      "value": "=>",
+    },
+    Object {
+      "loc": Object {
+        "end": Object {
+          "column": 30,
+          "line": 1,
+        },
+        "start": Object {
+          "column": 29,
+          "line": 1,
+        },
+      },
+      "range": Array [
+        29,
+        30,
+      ],
+      "type": "Identifier",
+      "value": "T",
+    },
+    Object {
+      "loc": Object {
+        "end": Object {
+          "column": 31,
+          "line": 1,
+        },
+        "start": Object {
+          "column": 30,
+          "line": 1,
+        },
+      },
+      "range": Array [
+        30,
+        31,
+      ],
+      "type": "Punctuator",
+      "value": ";",
+    },
+  ],
+  "type": "Program",
+}
+`;
diff --git a/packages/typescript-estree/tests/snapshots/typescript/types/template-literal-type-4.src.ts.shot b/packages/typescript-estree/tests/snapshots/typescript/types/template-literal-type-4.src.ts.shot
index fafb3e04c2f7..44900a50b51e 100644
--- a/packages/typescript-estree/tests/snapshots/typescript/types/template-literal-type-4.src.ts.shot
+++ b/packages/typescript-estree/tests/snapshots/typescript/types/template-literal-type-4.src.ts.shot
@@ -559,6 +559,7 @@ Object {
               "type": "TSStringKeyword",
             },
             "default": undefined,
+            "in": false,
             "loc": Object {
               "end": Object {
                 "column": 42,
@@ -587,6 +588,7 @@ Object {
               ],
               "type": "Identifier",
             },
+            "out": false,
             "range": Array [
               26,
               42,
diff --git a/packages/utils/CHANGELOG.md b/packages/utils/CHANGELOG.md
index 57db0424e2dd..1c374c4ca114 100644
--- a/packages/utils/CHANGELOG.md
+++ b/packages/utils/CHANGELOG.md
@@ -3,6 +3,14 @@
 All notable changes to this project will be documented in this file.
 See [Conventional Commits](https://conventionalcommits.org) for commit guidelines.
 
+# [5.26.0](https://github.com/typescript-eslint/typescript-eslint/compare/v5.25.0...v5.26.0) (2022-05-23)
+
+**Note:** Version bump only for package @typescript-eslint/utils
+
+
+
+
+
 # [5.25.0](https://github.com/typescript-eslint/typescript-eslint/compare/v5.24.0...v5.25.0) (2022-05-17)
 
 
diff --git a/packages/utils/jest.config.js b/packages/utils/jest.config.js
index 5f1ea3f4bcb0..910991b20cff 100644
--- a/packages/utils/jest.config.js
+++ b/packages/utils/jest.config.js
@@ -4,5 +4,4 @@
 /** @type {import('@jest/types').Config.InitialOptions} */
 module.exports = {
   ...require('../../jest.config.base.js'),
-  testRegex: './tests/.+\\.test\\.ts$',
 };
diff --git a/packages/utils/package.json b/packages/utils/package.json
index 130428868ca1..502ddbdea2c1 100644
--- a/packages/utils/package.json
+++ b/packages/utils/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@typescript-eslint/utils",
-  "version": "5.25.0",
+  "version": "5.26.0",
   "description": "Utilities for working with TypeScript + ESLint together",
   "keywords": [
     "eslint",
@@ -40,9 +40,9 @@
   },
   "dependencies": {
     "@types/json-schema": "^7.0.9",
-    "@typescript-eslint/scope-manager": "5.25.0",
-    "@typescript-eslint/types": "5.25.0",
-    "@typescript-eslint/typescript-estree": "5.25.0",
+    "@typescript-eslint/scope-manager": "5.26.0",
+    "@typescript-eslint/types": "5.26.0",
+    "@typescript-eslint/typescript-estree": "5.26.0",
     "eslint-scope": "^5.1.1",
     "eslint-utils": "^3.0.0"
   },
diff --git a/packages/visitor-keys/CHANGELOG.md b/packages/visitor-keys/CHANGELOG.md
index df600cb432ef..3447d5fcbe77 100644
--- a/packages/visitor-keys/CHANGELOG.md
+++ b/packages/visitor-keys/CHANGELOG.md
@@ -3,6 +3,17 @@
 All notable changes to this project will be documented in this file.
 See [Conventional Commits](https://conventionalcommits.org) for commit guidelines.
 
+# [5.26.0](https://github.com/typescript-eslint/typescript-eslint/compare/v5.25.0...v5.26.0) (2022-05-23)
+
+
+### Features
+
+* [4.7] support instantiation expressions ([#4938](https://github.com/typescript-eslint/typescript-eslint/issues/4938)) ([79fbc77](https://github.com/typescript-eslint/typescript-eslint/commit/79fbc7743ae5dce3190f8168776e0204755390ad))
+
+
+
+
+
 # [5.25.0](https://github.com/typescript-eslint/typescript-eslint/compare/v5.24.0...v5.25.0) (2022-05-17)
 
 **Note:** Version bump only for package @typescript-eslint/visitor-keys
diff --git a/packages/visitor-keys/jest.config.js b/packages/visitor-keys/jest.config.js
index 77fe4d022a95..910991b20cff 100644
--- a/packages/visitor-keys/jest.config.js
+++ b/packages/visitor-keys/jest.config.js
@@ -4,5 +4,4 @@
 /** @type {import('@jest/types').Config.InitialOptions} */
 module.exports = {
   ...require('../../jest.config.base.js'),
-  testRegex: ['./tests/.+\\.test\\.ts$'],
 };
diff --git a/packages/visitor-keys/package.json b/packages/visitor-keys/package.json
index 0cf35c8f412c..f7b0b512ace4 100644
--- a/packages/visitor-keys/package.json
+++ b/packages/visitor-keys/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@typescript-eslint/visitor-keys",
-  "version": "5.25.0",
+  "version": "5.26.0",
   "description": "Visitor keys used to help traverse the TypeScript-ESTree AST",
   "keywords": [
     "eslint",
@@ -38,7 +38,7 @@
     "typecheck": "tsc -p tsconfig.json --noEmit"
   },
   "dependencies": {
-    "@typescript-eslint/types": "5.25.0",
+    "@typescript-eslint/types": "5.26.0",
     "eslint-visitor-keys": "^3.3.0"
   },
   "devDependencies": {
diff --git a/packages/visitor-keys/src/visitor-keys.ts b/packages/visitor-keys/src/visitor-keys.ts
index 3e49d2d1b484..f7be9f1aed8c 100644
--- a/packages/visitor-keys/src/visitor-keys.ts
+++ b/packages/visitor-keys/src/visitor-keys.ts
@@ -100,6 +100,7 @@ const additionalKeys: AdditionalKeys = {
   TSIndexedAccessType: ['indexType', 'objectType'],
   TSIndexSignature: ['parameters', 'typeAnnotation'],
   TSInferType: ['typeParameter'],
+  TSInstantiationExpression: ['expression', 'typeParameters'],
   TSInterfaceBody: ['body'],
   TSInterfaceDeclaration: ['id', 'typeParameters', 'extends', 'body'],
   TSInterfaceHeritage: ['expression', 'typeParameters'],
diff --git a/packages/website-eslint/CHANGELOG.md b/packages/website-eslint/CHANGELOG.md
index f5a79fd6bb42..046524952cbb 100644
--- a/packages/website-eslint/CHANGELOG.md
+++ b/packages/website-eslint/CHANGELOG.md
@@ -3,6 +3,14 @@
 All notable changes to this project will be documented in this file.
 See [Conventional Commits](https://conventionalcommits.org) for commit guidelines.
 
+# [5.26.0](https://github.com/typescript-eslint/typescript-eslint/compare/v5.25.0...v5.26.0) (2022-05-23)
+
+**Note:** Version bump only for package @typescript-eslint/website-eslint
+
+
+
+
+
 # [5.25.0](https://github.com/typescript-eslint/typescript-eslint/compare/v5.24.0...v5.25.0) (2022-05-17)
 
 **Note:** Version bump only for package @typescript-eslint/website-eslint
diff --git a/packages/website-eslint/package.json b/packages/website-eslint/package.json
index d437e42c6c05..cdb3e2847d48 100644
--- a/packages/website-eslint/package.json
+++ b/packages/website-eslint/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@typescript-eslint/website-eslint",
-  "version": "5.25.0",
+  "version": "5.26.0",
   "private": true,
   "description": "ESLint which works in browsers.",
   "engines": {
@@ -16,19 +16,19 @@
     "format": "prettier --write \"./**/*.{ts,js,json,md}\" --ignore-path ../../.prettierignore"
   },
   "dependencies": {
-    "@typescript-eslint/types": "5.25.0",
-    "@typescript-eslint/utils": "5.25.0"
+    "@typescript-eslint/types": "5.26.0",
+    "@typescript-eslint/utils": "5.26.0"
   },
   "devDependencies": {
     "@rollup/plugin-commonjs": "^22.0.0",
     "@rollup/plugin-json": "^4.1.0",
     "@rollup/plugin-node-resolve": "^13.3.0",
     "@rollup/pluginutils": "^4.2.1",
-    "@typescript-eslint/eslint-plugin": "5.25.0",
-    "@typescript-eslint/parser": "5.25.0",
-    "@typescript-eslint/scope-manager": "5.25.0",
-    "@typescript-eslint/typescript-estree": "5.25.0",
-    "@typescript-eslint/visitor-keys": "5.25.0",
+    "@typescript-eslint/eslint-plugin": "5.26.0",
+    "@typescript-eslint/parser": "5.26.0",
+    "@typescript-eslint/scope-manager": "5.26.0",
+    "@typescript-eslint/typescript-estree": "5.26.0",
+    "@typescript-eslint/visitor-keys": "5.26.0",
     "eslint": "*",
     "rollup": "^2.72.1",
     "semver": "^7.3.7"
diff --git a/packages/website/CHANGELOG.md b/packages/website/CHANGELOG.md
index 3ffe4efc0eeb..0d22e43b1b43 100644
--- a/packages/website/CHANGELOG.md
+++ b/packages/website/CHANGELOG.md
@@ -3,6 +3,14 @@
 All notable changes to this project will be documented in this file.
 See [Conventional Commits](https://conventionalcommits.org) for commit guidelines.
 
+# [5.26.0](https://github.com/typescript-eslint/typescript-eslint/compare/v5.25.0...v5.26.0) (2022-05-23)
+
+**Note:** Version bump only for package website
+
+
+
+
+
 # [5.25.0](https://github.com/typescript-eslint/typescript-eslint/compare/v5.24.0...v5.25.0) (2022-05-17)
 
 **Note:** Version bump only for package website
diff --git a/packages/website/cypress.json b/packages/website/cypress.json
index 3f950c1a9af3..904719148b0f 100644
--- a/packages/website/cypress.json
+++ b/packages/website/cypress.json
@@ -1,4 +1,5 @@
 {
   "baseUrl": "http://localhost:3000",
-  "fixturesFolder": false
+  "fixturesFolder": false,
+  "pageLoadTimeout": 600000
 }
diff --git a/packages/website/docusaurus.config.js b/packages/website/docusaurus.config.js
index 7add99ed218c..a06a8e0367dc 100644
--- a/packages/website/docusaurus.config.js
+++ b/packages/website/docusaurus.config.js
@@ -15,8 +15,8 @@ const config = {
   tagline: 'Tooling which enables ESLint to support TypeScript',
   url: 'https://typescript-eslint.io',
   baseUrl: '/',
-  onBrokenLinks: 'warn', // TODO: 'throw'
-  onBrokenMarkdownLinks: 'warn',
+  onBrokenLinks: 'throw',
+  onBrokenMarkdownLinks: 'warn', // If Markdown link resolution fails, it will result in a broken link anyways
   favicon: 'img/favicon.ico',
   organizationName: 'typescript-eslint',
   projectName: 'typescript-eslint',
diff --git a/packages/website/package.json b/packages/website/package.json
index 8cf52af9233c..35309c4e44df 100644
--- a/packages/website/package.json
+++ b/packages/website/package.json
@@ -1,6 +1,6 @@
 {
   "name": "website",
-  "version": "5.25.0",
+  "version": "5.26.0",
   "private": true,
   "scripts": {
     "build": "docusaurus build",
@@ -14,13 +14,13 @@
     "test:open": "cypress open"
   },
   "dependencies": {
-    "@babel/runtime": "7.17.9",
+    "@babel/runtime": "7.18.0",
     "@docusaurus/core": "2.0.0-beta.20",
     "@docusaurus/preset-classic": "2.0.0-beta.20",
     "@docusaurus/remark-plugin-npm2yarn": "2.0.0-beta.20",
     "@docusaurus/theme-common": "2.0.0-beta.20",
     "@mdx-js/react": "1.6.22",
-    "@typescript-eslint/website-eslint": "5.25.0",
+    "@typescript-eslint/website-eslint": "5.26.0",
     "clsx": "^1.1.1",
     "eslint": "*",
     "json5": "^2.2.1",
@@ -37,7 +37,7 @@
     "@types/react-helmet": "^6.1.5",
     "@types/react-router-dom": "^5.3.3",
     "copy-webpack-plugin": "^10.2.4",
-    "cypress": "8.7.0",
+    "cypress": "8.3.0",
     "cypress-axe": "^0.14.0",
     "eslint-plugin-jsx-a11y": "^6.5.1",
     "eslint-plugin-react": "^7.29.4",
diff --git a/yarn.lock b/yarn.lock
index 95fbd5252d85..f2808b7eed8d 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -1145,10 +1145,10 @@
     core-js-pure "^3.20.2"
     regenerator-runtime "^0.13.4"
 
-"@babel/runtime@7.17.9", "@babel/runtime@^7.1.2", "@babel/runtime@^7.10.2", "@babel/runtime@^7.10.3", "@babel/runtime@^7.12.1", "@babel/runtime@^7.12.13", "@babel/runtime@^7.12.5", "@babel/runtime@^7.14.6", "@babel/runtime@^7.16.3", "@babel/runtime@^7.17.9", "@babel/runtime@^7.7.6", "@babel/runtime@^7.8.4":
-  version "7.17.9"
-  resolved "https://registry.yarnpkg.com/@babel/runtime/-/runtime-7.17.9.tgz#d19fbf802d01a8cb6cf053a64e472d42c434ba72"
-  integrity sha512-lSiBBvodq29uShpWGNbgFdKYNiFDo5/HIYsaCEY9ff4sb10x9jizo2+pRrSyF4jKZCXqgzuqBOQKbUm90gQwJg==
+"@babel/runtime@7.18.0", "@babel/runtime@^7.1.2", "@babel/runtime@^7.10.2", "@babel/runtime@^7.10.3", "@babel/runtime@^7.12.1", "@babel/runtime@^7.12.13", "@babel/runtime@^7.12.5", "@babel/runtime@^7.14.6", "@babel/runtime@^7.16.3", "@babel/runtime@^7.17.9", "@babel/runtime@^7.7.6", "@babel/runtime@^7.8.4":
+  version "7.18.0"
+  resolved "https://registry.yarnpkg.com/@babel/runtime/-/runtime-7.18.0.tgz#6d77142a19cb6088f0af662af1ada37a604d34ae"
+  integrity sha512-YMQvx/6nKEaucl0MY56mwIG483xk8SDNdlUwb2Ts6FUpr7fm85DxEmsY18LXBNhcTz6tO6JwZV8w1W06v8UKeg==
   dependencies:
     regenerator-runtime "^0.13.4"
 
@@ -1178,9 +1178,9 @@
     globals "^11.1.0"
 
 "@babel/types@^7.0.0", "@babel/types@^7.12.7", "@babel/types@^7.15.6", "@babel/types@^7.16.0", "@babel/types@^7.16.7", "@babel/types@^7.16.8", "@babel/types@^7.17.0", "@babel/types@^7.17.10", "@babel/types@^7.17.12", "@babel/types@^7.3.0", "@babel/types@^7.3.3", "@babel/types@^7.4.4":
-  version "7.17.12"
-  resolved "https://registry.yarnpkg.com/@babel/types/-/types-7.17.12.tgz#1210690a516489c0200f355d87619157fbbd69a0"
-  integrity sha512-rH8i29wcZ6x9xjzI5ILHL/yZkbQnCERdHlogKuIb4PUr7do4iT8DPekrTbBLWTnRQm6U0GYABbTMSzijmEqlAg==
+  version "7.18.0"
+  resolved "https://registry.yarnpkg.com/@babel/types/-/types-7.18.0.tgz#ef523ea349722849cb4bf806e9342ede4d071553"
+  integrity sha512-vhAmLPAiC8j9K2GnsnLPCIH5wCrPpYIVBCWRBFDCB7Y/BXLqi/O+1RSTTM2bsmg6U/551+FCf9PNPxjABmxHTw==
   dependencies:
     "@babel/helper-validator-identifier" "^7.16.7"
     to-fast-properties "^2.0.0"
@@ -1615,7 +1615,7 @@
   dependencies:
     "@cspotcode/source-map-consumer" "0.8.0"
 
-"@cypress/request@^2.88.6":
+"@cypress/request@^2.88.5":
   version "2.88.10"
   resolved "https://registry.yarnpkg.com/@cypress/request/-/request-2.88.10.tgz#b66d76b07f860d3a4b8d7a0604d020c662752cce"
   integrity sha512-Zp7F+R93N0yZyG34GutyTNr+okam7s/Fzc1+i3kcqOP8vk6OuajuE9qZJ6Rs+10/1JFtXFYMdyarnU1rZuJesg==
@@ -3071,9 +3071,9 @@
     "@rushstack/node-core-library" "3.45.5"
 
 "@microsoft/api-extractor@^7.23.2":
-  version "7.24.0"
-  resolved "https://registry.yarnpkg.com/@microsoft/api-extractor/-/api-extractor-7.24.0.tgz#be497360b06891ed8b660e7802c4503ceb736693"
-  integrity sha512-cC5Vcu3N2OJh1G5v136JYtE4QQtQYq6mLiL8YXzFgu8aoq8T88kzq3/TxlihJvqGnrD96pf4PjS2Yg8RNYTQYw==
+  version "7.24.1"
+  resolved "https://registry.yarnpkg.com/@microsoft/api-extractor/-/api-extractor-7.24.1.tgz#cbbe32a5f4f32717b60f593cdc172b99e5c76fae"
+  integrity sha512-RjcKRvKRAtTK4z8UdC2qYsvgTYHEYvdsqF4QGoX4mNAVo7s6Jj4zcHtSrMEQMTUHujZbSd5+ihI5ktISp338mQ==
   dependencies:
     "@microsoft/api-extractor-model" "7.17.3"
     "@microsoft/tsdoc" "0.14.1"
@@ -3674,89 +3674,89 @@
   dependencies:
     source-map-support "^0.5.21"
 
-"@swc/core-android-arm-eabi@1.2.185":
-  version "1.2.185"
-  resolved "https://registry.yarnpkg.com/@swc/core-android-arm-eabi/-/core-android-arm-eabi-1.2.185.tgz#6fca8a364428c3ff17fd960176a8c5a1047748c4"
-  integrity sha512-/ZTj5yaPkPC0UwggYN+y4d2DNZJI+b1y1gi4twrQJz997OMU032Hi9/59VxHFzHNxlzhIuCJYcbxOxi1Aqk2bA==
-
-"@swc/core-android-arm64@1.2.185":
-  version "1.2.185"
-  resolved "https://registry.yarnpkg.com/@swc/core-android-arm64/-/core-android-arm64-1.2.185.tgz#592fa96fb17036d920f57c8f36c859acf1dacb53"
-  integrity sha512-TgidzM+7H0YTIABu2ILI8MRDiIzcFULz5vIUWbhLwypPH9vJCFcDnAv5rBpg/4KBMzuSI6BNNBIcf/8Wc9e0HA==
-
-"@swc/core-darwin-arm64@1.2.185":
-  version "1.2.185"
-  resolved "https://registry.yarnpkg.com/@swc/core-darwin-arm64/-/core-darwin-arm64-1.2.185.tgz#5dfbb3425ddf479c8875a3737e1de5b127e335b2"
-  integrity sha512-segMc9FVYz+M5KzpPJR+M20Mmeq4ZQw4gi6rt0HXNpSPykm+oe/wb1CZbMk/9SpMaevpXOOZa0HHBM2ue+WhVA==
-
-"@swc/core-darwin-x64@1.2.185":
-  version "1.2.185"
-  resolved "https://registry.yarnpkg.com/@swc/core-darwin-x64/-/core-darwin-x64-1.2.185.tgz#e97ed012ff08fb39dcc51fc07233f4425fa89408"
-  integrity sha512-PL1Xq6R5zpBbYZsWJU0xK2/WQlhag/Kiq1eZd6ftSLaxn0q00wdSGPpzOqK5FTYAqi+5R1CWM/kCOHFoSlYDfg==
-
-"@swc/core-freebsd-x64@1.2.185":
-  version "1.2.185"
-  resolved "https://registry.yarnpkg.com/@swc/core-freebsd-x64/-/core-freebsd-x64-1.2.185.tgz#ba12147270c754c47eee9a99f08de75172ae4bb1"
-  integrity sha512-scaFxGfV7RhJrrCGzouwFe1XOzJvY/WjYWysHuD+slSdn3pjSnxXtX2Q9jPIYF0bmIcbTp4D6V8VITLhmfkzEA==
-
-"@swc/core-linux-arm-gnueabihf@1.2.185":
-  version "1.2.185"
-  resolved "https://registry.yarnpkg.com/@swc/core-linux-arm-gnueabihf/-/core-linux-arm-gnueabihf-1.2.185.tgz#4bd8ff733e06c8ea0dc916208f8fdeb907f25256"
-  integrity sha512-WQ84BVGF0al3ynWBeXuEpO7y6h8Bh4AXr+Ys2YaEgyZtAZ6zWUi3Ca4ktFWwpACSm0XUUB3lhlapUcqXJE8lZg==
-
-"@swc/core-linux-arm64-gnu@1.2.185":
-  version "1.2.185"
-  resolved "https://registry.yarnpkg.com/@swc/core-linux-arm64-gnu/-/core-linux-arm64-gnu-1.2.185.tgz#8abe168271f4ba6767da87fb4386ccea388fc324"
-  integrity sha512-INrmHqV5ti0ROS9FeGXPF5ZcIAWZ9Sp+Xbn5isWZ9owqT0c2CU4f9+w+OzNMMDKVFe2ARvlH/D927mLIgwqDmQ==
-
-"@swc/core-linux-arm64-musl@1.2.185":
-  version "1.2.185"
-  resolved "https://registry.yarnpkg.com/@swc/core-linux-arm64-musl/-/core-linux-arm64-musl-1.2.185.tgz#2352673452ac2553d45181d53351cb00d378d848"
-  integrity sha512-OEwVBlypM7SOZqpa82hIh9jeiu/eSXG+J+R0vekcWz7EkW5zb504uyGPeZJKMqX23I5GZtBpk96UUbhnNCaYUg==
-
-"@swc/core-linux-x64-gnu@1.2.185":
-  version "1.2.185"
-  resolved "https://registry.yarnpkg.com/@swc/core-linux-x64-gnu/-/core-linux-x64-gnu-1.2.185.tgz#058444fa372374f2f7f2f2d09c03085f928c8f12"
-  integrity sha512-H8LnCdViP7JsFlDE02w5czlKQWnAAM9ZN3oZnvAuTod2gJBjTJ4eZ3h9d+EQdcszw7Csh+IwXbmPz0mPwaR0vQ==
-
-"@swc/core-linux-x64-musl@1.2.185":
-  version "1.2.185"
-  resolved "https://registry.yarnpkg.com/@swc/core-linux-x64-musl/-/core-linux-x64-musl-1.2.185.tgz#a8f473965e87acb03057d6b4790f86857e5ce4ea"
-  integrity sha512-DRHmhjCsA2FloF+6/HMxJ8bkdfddAY/wqnpuW/l3CPUyL3VMDmvSiZICN8f/J8LKpGfDV2FdczztmbGi14jO+g==
-
-"@swc/core-win32-arm64-msvc@1.2.185":
-  version "1.2.185"
-  resolved "https://registry.yarnpkg.com/@swc/core-win32-arm64-msvc/-/core-win32-arm64-msvc-1.2.185.tgz#d8fc5bf11e67664d54a84ad37d9ac7d69df1a317"
-  integrity sha512-0BmuvU+Lfz5n1/ihh30UF2Viu9JJn3S3YC9QD9BfF80ueEl8KT4JihhJGuEG3XuZk5+35o2oZiCRkn6NKI/qpA==
-
-"@swc/core-win32-ia32-msvc@1.2.185":
-  version "1.2.185"
-  resolved "https://registry.yarnpkg.com/@swc/core-win32-ia32-msvc/-/core-win32-ia32-msvc-1.2.185.tgz#cbd3a4ad67bf40754143fafc87baed6021e9a780"
-  integrity sha512-yRNa/frm5MeXJMpj6V6uQy5a0yfO9q6ZOQ4L+439UH8vBcgIZYOG07bJGvxeUjaKkkrhfzEu5Q8fdXTzPgGeAA==
-
-"@swc/core-win32-x64-msvc@1.2.185":
-  version "1.2.185"
-  resolved "https://registry.yarnpkg.com/@swc/core-win32-x64-msvc/-/core-win32-x64-msvc-1.2.185.tgz#f2459a88783ed95257229e41034fd913b487c5b4"
-  integrity sha512-nLF0AKADjeR3Rr05lWoKOeDbGBFpmbFnGkpLJK9EAwAIQUC9lDRYIps5yinPZsgqBwa0RCUsxzS3PjbWEY18bg==
+"@swc/core-android-arm-eabi@1.2.189":
+  version "1.2.189"
+  resolved "https://registry.yarnpkg.com/@swc/core-android-arm-eabi/-/core-android-arm-eabi-1.2.189.tgz#a8060c2ec7bd93bd9907c3059c44a832eda57b6d"
+  integrity sha512-0kN3Le6QzFFz+Lc6a/tf/RkJXubWwWaHxF4c0bVm4AKIFf4nRlUCEqEkjdVaZvL92rpBMHaEEBuIIz3T8DqTTQ==
+
+"@swc/core-android-arm64@1.2.189":
+  version "1.2.189"
+  resolved "https://registry.yarnpkg.com/@swc/core-android-arm64/-/core-android-arm64-1.2.189.tgz#c9a7ebaecbef4488db3394e660dd5c2abfa5c173"
+  integrity sha512-smsb+YkDw2OKwg66Z63E/G4NlFApDbsiOPmZXFZbtZbNBD9v+wnk6WVA//XR1bdUI9VbzNKlMPKJxQTE685QDw==
+
+"@swc/core-darwin-arm64@1.2.189":
+  version "1.2.189"
+  resolved "https://registry.yarnpkg.com/@swc/core-darwin-arm64/-/core-darwin-arm64-1.2.189.tgz#883098686504692218e88877b224e06db2a93c86"
+  integrity sha512-OGjZRkTulKirJMLYbW9etb59lA9ueDXVwYRVD9SrNh8tRMTf0Nq+SUT/C3LVhBBGC4KSdWOzBAYbDTTdsnY++Q==
+
+"@swc/core-darwin-x64@1.2.189":
+  version "1.2.189"
+  resolved "https://registry.yarnpkg.com/@swc/core-darwin-x64/-/core-darwin-x64-1.2.189.tgz#38ba12dc3b07d96761dc895dd43e14ba3323129f"
+  integrity sha512-BEcxnBHx51514Voe2dn/y1y5H9VNyw7Zpp9+mPekZqx5o/onPD5wZ1ZfAsPrA4UlvM3v16u6ITE/cLawJ/GdAQ==
+
+"@swc/core-freebsd-x64@1.2.189":
+  version "1.2.189"
+  resolved "https://registry.yarnpkg.com/@swc/core-freebsd-x64/-/core-freebsd-x64-1.2.189.tgz#0cee19a1382ee97a7be2ea057cf48f5e08c66038"
+  integrity sha512-B6g2NWeh2iw6WPOaM19Uj3VE4se6alT265kWibLUshjcofRfnYT1lNhhkrF1D0EVnpC8I96I/xXNQo4Am9z4zQ==
+
+"@swc/core-linux-arm-gnueabihf@1.2.189":
+  version "1.2.189"
+  resolved "https://registry.yarnpkg.com/@swc/core-linux-arm-gnueabihf/-/core-linux-arm-gnueabihf-1.2.189.tgz#612010e31969387de6acde69d8250fd74f784be1"
+  integrity sha512-6WhPG9pyN5AahQTVQk8MoN1I9Z/Ytfqizuie1wV7mW8FMNmMkiJvBekKtE6ftxu80Hqa34r86WfEwmJKm5MqYw==
+
+"@swc/core-linux-arm64-gnu@1.2.189":
+  version "1.2.189"
+  resolved "https://registry.yarnpkg.com/@swc/core-linux-arm64-gnu/-/core-linux-arm64-gnu-1.2.189.tgz#0fe98d1ca0a3441bfe4033fbe7fc19d87019f640"
+  integrity sha512-frJTGnxsDe7h2d7BtnBivOdOJTtabkQIIZmHd4JHqafcoekI6teyveIax17axLyimvWl278yTo3hf7ePagD/eg==
+
+"@swc/core-linux-arm64-musl@1.2.189":
+  version "1.2.189"
+  resolved "https://registry.yarnpkg.com/@swc/core-linux-arm64-musl/-/core-linux-arm64-musl-1.2.189.tgz#bb28e598e028745129e0eb9458184eb5b7efe685"
+  integrity sha512-27K38LoZpME5lojDJIUNo7zdTDwAKLm0BMQ7HXWcYOyiDAekhSidI+SrBWxCfLzfuClhFu6/VE3E7j32VFJsiA==
+
+"@swc/core-linux-x64-gnu@1.2.189":
+  version "1.2.189"
+  resolved "https://registry.yarnpkg.com/@swc/core-linux-x64-gnu/-/core-linux-x64-gnu-1.2.189.tgz#365073c3183e40080be900337987fcc4d2270fff"
+  integrity sha512-Ha5oJKOyQm9w7+e+WdRm4ypijzEmglWZGtgBR6vV6ViqqHcTBAU4nG87ex7y7AS9p+Cbc6EOSR9X1qIB8KxtbA==
+
+"@swc/core-linux-x64-musl@1.2.189":
+  version "1.2.189"
+  resolved "https://registry.yarnpkg.com/@swc/core-linux-x64-musl/-/core-linux-x64-musl-1.2.189.tgz#1ce88e44952d0d4f525016c7841c1443f91de788"
+  integrity sha512-/p5yXa9HEzpVEuE4ivkW1IvwyYu6fT+L2OvVEs5oXIba80F0Wjy7InWqaa83gwrdMH+bXV6loG8LzZUZu/lpjA==
+
+"@swc/core-win32-arm64-msvc@1.2.189":
+  version "1.2.189"
+  resolved "https://registry.yarnpkg.com/@swc/core-win32-arm64-msvc/-/core-win32-arm64-msvc-1.2.189.tgz#2ad4d2aacd0032c1f8a859bba963207436a78769"
+  integrity sha512-o/1ueM6/sifNjYnO6NMEXB895spVfJs5oQIPxQG9vJ/4zWLw8YmAx+u1xJY+XGyK6gnroHt7yPiS87qWdbeF6w==
+
+"@swc/core-win32-ia32-msvc@1.2.189":
+  version "1.2.189"
+  resolved "https://registry.yarnpkg.com/@swc/core-win32-ia32-msvc/-/core-win32-ia32-msvc-1.2.189.tgz#93dee76f59760b8eb516a2e55111fdeaf1e8c6c8"
+  integrity sha512-YDwRkzykaf+dw5Z7u189cC/Tttkn2NVV84hrGL3LbVuh7wT5PaDhZs4Yz4unZQSlPV12olmZWgNr/i27h5wlpg==
+
+"@swc/core-win32-x64-msvc@1.2.189":
+  version "1.2.189"
+  resolved "https://registry.yarnpkg.com/@swc/core-win32-x64-msvc/-/core-win32-x64-msvc-1.2.189.tgz#eeb127740952e3dd5cae2866c2da60346fed457b"
+  integrity sha512-Nge8Z/ZkAp5p5No50yBDpBG7+ZYaVWGSuwtPj6OJe7orzvDCEm9GgcVE6J9GEjbclSWlCH8B8lUe17GaKRZHbg==
 
 "@swc/core@^1.2.119", "@swc/core@^1.2.173", "@swc/core@^1.2.181":
-  version "1.2.185"
-  resolved "https://registry.yarnpkg.com/@swc/core/-/core-1.2.185.tgz#26cdc7f9417fd2f04fde7f97d0b217aaa1bc8d3b"
-  integrity sha512-dDNzDrJ4bzMVWeFWqLJojjv5XZJZ84Zia7kQdJjp+kfOMdEhS+onrAwrk5Q88PlAvbrhY6kQbWD2LZ8JdyEaSQ==
+  version "1.2.189"
+  resolved "https://registry.yarnpkg.com/@swc/core/-/core-1.2.189.tgz#8db88e809764e5b3b2be3fcac0da9d9d957e1056"
+  integrity sha512-S5cKX4ECMSfW78DLFgnlilJZgjrFRYwPslrrwpLl3gpwh+Qo72/Mhn71u7G/5xXW+T/xW5GwPccHfCk+k72uUg==
   optionalDependencies:
-    "@swc/core-android-arm-eabi" "1.2.185"
-    "@swc/core-android-arm64" "1.2.185"
-    "@swc/core-darwin-arm64" "1.2.185"
-    "@swc/core-darwin-x64" "1.2.185"
-    "@swc/core-freebsd-x64" "1.2.185"
-    "@swc/core-linux-arm-gnueabihf" "1.2.185"
-    "@swc/core-linux-arm64-gnu" "1.2.185"
-    "@swc/core-linux-arm64-musl" "1.2.185"
-    "@swc/core-linux-x64-gnu" "1.2.185"
-    "@swc/core-linux-x64-musl" "1.2.185"
-    "@swc/core-win32-arm64-msvc" "1.2.185"
-    "@swc/core-win32-ia32-msvc" "1.2.185"
-    "@swc/core-win32-x64-msvc" "1.2.185"
+    "@swc/core-android-arm-eabi" "1.2.189"
+    "@swc/core-android-arm64" "1.2.189"
+    "@swc/core-darwin-arm64" "1.2.189"
+    "@swc/core-darwin-x64" "1.2.189"
+    "@swc/core-freebsd-x64" "1.2.189"
+    "@swc/core-linux-arm-gnueabihf" "1.2.189"
+    "@swc/core-linux-arm64-gnu" "1.2.189"
+    "@swc/core-linux-arm64-musl" "1.2.189"
+    "@swc/core-linux-x64-gnu" "1.2.189"
+    "@swc/core-linux-x64-musl" "1.2.189"
+    "@swc/core-win32-arm64-msvc" "1.2.189"
+    "@swc/core-win32-ia32-msvc" "1.2.189"
+    "@swc/core-win32-x64-msvc" "1.2.189"
 
 "@swc/jest@^0.2.21":
   version "0.2.21"
@@ -4703,14 +4703,14 @@ array-ify@^1.0.0:
   resolved "https://registry.yarnpkg.com/array-ify/-/array-ify-1.0.0.tgz#9e528762b4a9066ad163a6962a364418e9626ece"
   integrity sha1-nlKHYrSpBmrRY6aWKjZEGOlibs4=
 
-array-includes@^3.1.3, array-includes@^3.1.4:
-  version "3.1.4"
-  resolved "https://registry.yarnpkg.com/array-includes/-/array-includes-3.1.4.tgz#f5b493162c760f3539631f005ba2bb46acb45ba9"
-  integrity sha512-ZTNSQkmWumEbiHO2GF4GmWxYVTiQyJy2XOTa15sdQSrvKn7l+180egQMqlrMOUMCyLMD7pmyQe4mMDUT6Behrw==
+array-includes@^3.1.3, array-includes@^3.1.4, array-includes@^3.1.5:
+  version "3.1.5"
+  resolved "https://registry.yarnpkg.com/array-includes/-/array-includes-3.1.5.tgz#2c320010db8d31031fd2a5f6b3bbd4b1aad31bdb"
+  integrity sha512-iSDYZMMyTPkiFasVqfuAQnWAYcvO/SeBSCGKePoEthjp4LEMTe4uLc7b025o4jAZpHhihh8xPo99TNWUWWkGDQ==
   dependencies:
     call-bind "^1.0.2"
-    define-properties "^1.1.3"
-    es-abstract "^1.19.1"
+    define-properties "^1.1.4"
+    es-abstract "^1.19.5"
     get-intrinsic "^1.1.1"
     is-string "^1.0.7"
 
@@ -4738,14 +4738,15 @@ array.prototype.flat@^1.2.5:
     define-properties "^1.1.3"
     es-abstract "^1.19.0"
 
-array.prototype.flatmap@^1.2.5:
-  version "1.2.5"
-  resolved "https://registry.yarnpkg.com/array.prototype.flatmap/-/array.prototype.flatmap-1.2.5.tgz#908dc82d8a406930fdf38598d51e7411d18d4446"
-  integrity sha512-08u6rVyi1Lj7oqWbS9nUxliETrtIROT4XGTA4D/LWGten6E3ocm7cy9SIrmNHOL5XVbVuckUp3X6Xyg8/zpvHA==
+array.prototype.flatmap@^1.3.0:
+  version "1.3.0"
+  resolved "https://registry.yarnpkg.com/array.prototype.flatmap/-/array.prototype.flatmap-1.3.0.tgz#a7e8ed4225f4788a70cd910abcf0791e76a5534f"
+  integrity sha512-PZC9/8TKAIxcWKdyeb77EzULHPrIX/tIZebLJUQOMR1OwYosT8yggdfWScfTBCDj5utONvOuPQQumYsU2ULbkg==
   dependencies:
-    call-bind "^1.0.0"
+    call-bind "^1.0.2"
     define-properties "^1.1.3"
-    es-abstract "^1.19.0"
+    es-abstract "^1.19.2"
+    es-shim-unscopables "^1.0.0"
 
 arrify@^1.0.1:
   version "1.0.1"
@@ -6290,12 +6291,12 @@ cypress-axe@^0.14.0:
   resolved "https://registry.yarnpkg.com/cypress-axe/-/cypress-axe-0.14.0.tgz#5f5e70fb36b8cb3ba73a8ba01e9262ff1268d5e2"
   integrity sha512-7Rdjnko0MjggCmndc1wECAkvQBIhuy+DRtjF7bd5YPZRFvubfMNvrxfqD8PWQmxm7MZE0ffS4Xr43V6ZmvLopg==
 
-cypress@8.7.0:
-  version "8.7.0"
-  resolved "https://registry.yarnpkg.com/cypress/-/cypress-8.7.0.tgz#2ee371f383d8f233d3425b6cc26ddeec2668b6da"
-  integrity sha512-b1bMC3VQydC6sXzBMFnSqcvwc9dTZMgcaOzT0vpSD+Gq1yFc+72JDWi55sfUK5eIeNLAtWOGy1NNb6UlhMvB+Q==
+cypress@8.3.0:
+  version "8.3.0"
+  resolved "https://registry.yarnpkg.com/cypress/-/cypress-8.3.0.tgz#ba906d2170888073ad94b2be1b994a749bbb7c7d"
+  integrity sha512-zA5Rcq8AZIfRfPXU0CCcauofF+YpaU9HYbfqkunFTmFV0Kdlo14tNjH2E3++MkjXKFnv3/pXq+HgxWtw8CSe8Q==
   dependencies:
-    "@cypress/request" "^2.88.6"
+    "@cypress/request" "^2.88.5"
     "@cypress/xvfb" "^1.2.4"
     "@types/node" "^14.14.31"
     "@types/sinonjs__fake-timers" "^6.0.2"
@@ -6329,7 +6330,6 @@ cypress@8.7.0:
     minimist "^1.2.5"
     ospath "^1.2.2"
     pretty-bytes "^5.6.0"
-    proxy-from-env "1.0.0"
     ramda "~0.27.1"
     request-progress "^3.0.0"
     supports-color "^8.1.1"
@@ -6495,6 +6495,14 @@ define-properties@^1.1.3:
   dependencies:
     object-keys "^1.0.12"
 
+define-properties@^1.1.4:
+  version "1.1.4"
+  resolved "https://registry.yarnpkg.com/define-properties/-/define-properties-1.1.4.tgz#0b14d7bd7fbeb2f3572c3a7eda80ea5d57fb05b1"
+  integrity sha512-uckOqKcfaVvtBdsVkdPv3XjveQJsNQqmhXgRi8uhvWWuPYZCNlzT8qAyblUgNoXdHdjMTzAqeGjAoli8f+bzPA==
+  dependencies:
+    has-property-descriptors "^1.0.0"
+    object-keys "^1.1.1"
+
 del@^6.0.0:
   version "6.0.0"
   resolved "https://registry.yarnpkg.com/del/-/del-6.0.0.tgz#0b40d0332cea743f1614f818be4feb717714c952"
@@ -6937,11 +6945,47 @@ es-abstract@^1.19.0, es-abstract@^1.19.1:
     string.prototype.trimstart "^1.0.4"
     unbox-primitive "^1.0.1"
 
+es-abstract@^1.19.2, es-abstract@^1.19.5:
+  version "1.20.1"
+  resolved "https://registry.yarnpkg.com/es-abstract/-/es-abstract-1.20.1.tgz#027292cd6ef44bd12b1913b828116f54787d1814"
+  integrity sha512-WEm2oBhfoI2sImeM4OF2zE2V3BYdSF+KnSi9Sidz51fQHd7+JuF8Xgcj9/0o+OWeIeIS/MiuNnlruQrJf16GQA==
+  dependencies:
+    call-bind "^1.0.2"
+    es-to-primitive "^1.2.1"
+    function-bind "^1.1.1"
+    function.prototype.name "^1.1.5"
+    get-intrinsic "^1.1.1"
+    get-symbol-description "^1.0.0"
+    has "^1.0.3"
+    has-property-descriptors "^1.0.0"
+    has-symbols "^1.0.3"
+    internal-slot "^1.0.3"
+    is-callable "^1.2.4"
+    is-negative-zero "^2.0.2"
+    is-regex "^1.1.4"
+    is-shared-array-buffer "^1.0.2"
+    is-string "^1.0.7"
+    is-weakref "^1.0.2"
+    object-inspect "^1.12.0"
+    object-keys "^1.1.1"
+    object.assign "^4.1.2"
+    regexp.prototype.flags "^1.4.3"
+    string.prototype.trimend "^1.0.5"
+    string.prototype.trimstart "^1.0.5"
+    unbox-primitive "^1.0.2"
+
 es-module-lexer@^0.9.0:
   version "0.9.3"
   resolved "https://registry.yarnpkg.com/es-module-lexer/-/es-module-lexer-0.9.3.tgz#6f13db00cc38417137daf74366f535c8eb438f19"
   integrity sha512-1HQ2M2sPtxwnvOvT1ZClHyQDiggdNjURWpY2we6aMKCQiUVxTmVs2UYPLIrD84sS+kMdUwfBSylbJPwNnBrnHQ==
 
+es-shim-unscopables@^1.0.0:
+  version "1.0.0"
+  resolved "https://registry.yarnpkg.com/es-shim-unscopables/-/es-shim-unscopables-1.0.0.tgz#702e632193201e3edf8713635d083d378e510241"
+  integrity sha512-Jm6GPcCdC30eMLbZ2x8z2WuRwAws3zTBBKuusffYVUrNj/GVSUAZ+xKMaUpfNDR5IbyNA5LJbaecoUVbmUcB1w==
+  dependencies:
+    has "^1.0.3"
+
 es-to-primitive@^1.2.1:
   version "1.2.1"
   resolved "https://registry.yarnpkg.com/es-to-primitive/-/es-to-primitive-1.2.1.tgz#e55cd4c9cdc188bcefb03b366c736323fc5c898a"
@@ -7063,24 +7107,24 @@ eslint-plugin-react-hooks@^4.5.0:
   integrity sha512-8k1gRt7D7h03kd+SAAlzXkQwWK22BnK6GKZG+FJA6BAGy22CFvl8kCIXKpVux0cCxMWDQUPqSok0LKaZ0aOcCw==
 
 eslint-plugin-react@^7.29.4:
-  version "7.29.4"
-  resolved "https://registry.yarnpkg.com/eslint-plugin-react/-/eslint-plugin-react-7.29.4.tgz#4717de5227f55f3801a5fd51a16a4fa22b5914d2"
-  integrity sha512-CVCXajliVh509PcZYRFyu/BoUEz452+jtQJq2b3Bae4v3xBUWPLCmtmBM+ZinG4MzwmxJgJ2M5rMqhqLVn7MtQ==
+  version "7.30.0"
+  resolved "https://registry.yarnpkg.com/eslint-plugin-react/-/eslint-plugin-react-7.30.0.tgz#8e7b1b2934b8426ac067a0febade1b13bd7064e3"
+  integrity sha512-RgwH7hjW48BleKsYyHK5vUAvxtE9SMPDKmcPRQgtRCYaZA0XQPt5FSkrU3nhz5ifzMZcA8opwmRJ2cmOO8tr5A==
   dependencies:
-    array-includes "^3.1.4"
-    array.prototype.flatmap "^1.2.5"
+    array-includes "^3.1.5"
+    array.prototype.flatmap "^1.3.0"
     doctrine "^2.1.0"
     estraverse "^5.3.0"
     jsx-ast-utils "^2.4.1 || ^3.0.0"
     minimatch "^3.1.2"
     object.entries "^1.1.5"
     object.fromentries "^2.0.5"
-    object.hasown "^1.1.0"
+    object.hasown "^1.1.1"
     object.values "^1.1.5"
     prop-types "^15.8.1"
     resolve "^2.0.0-next.3"
     semver "^6.3.0"
-    string.prototype.matchall "^4.0.6"
+    string.prototype.matchall "^4.0.7"
 
 eslint-plugin-simple-import-sort@^7.0.0:
   version "7.0.0"
@@ -7778,11 +7822,26 @@ function-bind@^1.1.1:
   resolved "https://registry.yarnpkg.com/function-bind/-/function-bind-1.1.1.tgz#a56899d3ea3c9bab874bb9773b7c5ede92f4895d"
   integrity sha512-yIovAzMX49sF8Yl58fSCWJ5svSLuaibPxXQJFLmBObTuCr0Mf1KiPopGM9NiFjiYBCbfaa2Fh6breQ6ANVTI0A==
 
+function.prototype.name@^1.1.5:
+  version "1.1.5"
+  resolved "https://registry.yarnpkg.com/function.prototype.name/-/function.prototype.name-1.1.5.tgz#cce0505fe1ffb80503e6f9e46cc64e46a12a9621"
+  integrity sha512-uN7m/BzVKQnCUF/iW8jYea67v++2u7m5UgENbHRtdDVclOUP+FMPlCNdmk0h/ysGyo2tavMJEDqJAkJdRa1vMA==
+  dependencies:
+    call-bind "^1.0.2"
+    define-properties "^1.1.3"
+    es-abstract "^1.19.0"
+    functions-have-names "^1.2.2"
+
 functional-red-black-tree@^1.0.1:
   version "1.0.1"
   resolved "https://registry.yarnpkg.com/functional-red-black-tree/-/functional-red-black-tree-1.0.1.tgz#1b0ab3bd553b2a0d6399d29c0e3ea0b252078327"
   integrity sha1-GwqzvVU7Kg1jmdKcDj6gslIHgyc=
 
+functions-have-names@^1.2.2:
+  version "1.2.3"
+  resolved "https://registry.yarnpkg.com/functions-have-names/-/functions-have-names-1.2.3.tgz#0404fe4ee2ba2f607f0e0ec3c80bae994133b834"
+  integrity sha512-xckBUXyTIqT97tq2x2AMb+g163b5JFysYk0x4qxNFwbfQkmNZoiRHb6sPzI9/QV33WeuvVYBUIiD4NzNIyqaRQ==
+
 gauge@~2.7.3:
   version "2.7.4"
   resolved "https://registry.yarnpkg.com/gauge/-/gauge-2.7.4.tgz#2c03405c7538c39d7eb37b317022e325fb018bf7"
@@ -8175,6 +8234,11 @@ has-bigints@^1.0.1:
   resolved "https://registry.yarnpkg.com/has-bigints/-/has-bigints-1.0.1.tgz#64fe6acb020673e3b78db035a5af69aa9d07b113"
   integrity sha512-LSBS2LjbNBTf6287JEbEzvJgftkF5qFkmCo9hDRpAzKhUOlJ+hx8dd4USs00SgsUNwc4617J9ki5YtEClM2ffA==
 
+has-bigints@^1.0.2:
+  version "1.0.2"
+  resolved "https://registry.yarnpkg.com/has-bigints/-/has-bigints-1.0.2.tgz#0871bd3e3d51626f6ca0966668ba35d5602d6eaa"
+  integrity sha512-tSvCKtBr9lkF0Ex0aQiP9N+OpV4zi2r/Nee5VkRDbaqv35RLYMzbwQfFSZZH0kR+Rd6302UJZ2p/bJCEoR3VoQ==
+
 has-flag@^3.0.0:
   version "3.0.0"
   resolved "https://registry.yarnpkg.com/has-flag/-/has-flag-3.0.0.tgz#b5d454dc2199ae225699f3467e5a07f3b955bafd"
@@ -8190,11 +8254,23 @@ has-own-prop@^2.0.0:
   resolved "https://registry.yarnpkg.com/has-own-prop/-/has-own-prop-2.0.0.tgz#f0f95d58f65804f5d218db32563bb85b8e0417af"
   integrity sha512-Pq0h+hvsVm6dDEa8x82GnLSYHOzNDt7f0ddFa3FqcQlgzEiptPqL+XrOJNavjOzSYiYWIrgeVYYgGlLmnxwilQ==
 
+has-property-descriptors@^1.0.0:
+  version "1.0.0"
+  resolved "https://registry.yarnpkg.com/has-property-descriptors/-/has-property-descriptors-1.0.0.tgz#610708600606d36961ed04c196193b6a607fa861"
+  integrity sha512-62DVLZGoiEBDHQyqG4w9xCuZ7eJEwNmJRWw2VY84Oedb7WFcA27fiEVe8oUQx9hAUJ4ekurquucTGwsyO1XGdQ==
+  dependencies:
+    get-intrinsic "^1.1.1"
+
 has-symbols@^1.0.1, has-symbols@^1.0.2:
   version "1.0.2"
   resolved "https://registry.yarnpkg.com/has-symbols/-/has-symbols-1.0.2.tgz#165d3070c00309752a1236a479331e3ac56f1423"
   integrity sha512-chXa79rL/UC2KlX17jo3vRGz0azaWEx5tGqZg5pO3NUyEJVB17dMruQlzCCOfUvElghKcm5194+BCRvi2Rv/Gw==
 
+has-symbols@^1.0.3:
+  version "1.0.3"
+  resolved "https://registry.yarnpkg.com/has-symbols/-/has-symbols-1.0.3.tgz#bb7b2c4349251dce87b125f7bdf874aa7c8b39f8"
+  integrity sha512-l3LCuF6MgDNwTDKkdYGEihYjt5pRPbEg46rtlmnSPlUbgmB8LOIrKJbYYFBSbnPaJexMKtiPO8hmeRjRz2Td+A==
+
 has-tostringtag@^1.0.0:
   version "1.0.0"
   resolved "https://registry.yarnpkg.com/has-tostringtag/-/has-tostringtag-1.0.0.tgz#7e133818a7d394734f941e73c3d3f9291e658b25"
@@ -8928,6 +9004,11 @@ is-negative-zero@^2.0.1:
   resolved "https://registry.yarnpkg.com/is-negative-zero/-/is-negative-zero-2.0.1.tgz#3de746c18dda2319241a53675908d8f766f11c24"
   integrity sha512-2z6JzQvZRa9A2Y7xC6dQQm4FSTSTNWjKIYYTt4246eMTJmIo0Q+ZyOsU66X8lxK1AbB92dFeglPLrhwpeRKO6w==
 
+is-negative-zero@^2.0.2:
+  version "2.0.2"
+  resolved "https://registry.yarnpkg.com/is-negative-zero/-/is-negative-zero-2.0.2.tgz#7bf6f03a28003b8b3965de3ac26f664d765f3150"
+  integrity sha512-dqJvarLawXsFbNDeJW7zAz8ItJ9cd28YufuuFzh0G8pNHjJMnY08Dv7sYX2uF5UpQOwieAeOExEYAWWfu7ZZUA==
+
 is-npm@^5.0.0:
   version "5.0.0"
   resolved "https://registry.yarnpkg.com/is-npm/-/is-npm-5.0.0.tgz#43e8d65cc56e1b67f8d47262cf667099193f45a8"
@@ -9022,6 +9103,13 @@ is-shared-array-buffer@^1.0.1:
   resolved "https://registry.yarnpkg.com/is-shared-array-buffer/-/is-shared-array-buffer-1.0.1.tgz#97b0c85fbdacb59c9c446fe653b82cf2b5b7cfe6"
   integrity sha512-IU0NmyknYZN0rChcKhRO1X8LYz5Isj/Fsqh8NJOSf+N/hCOTwy29F32Ik7a+QszE63IdvmwdTPDd6cZ5pg4cwA==
 
+is-shared-array-buffer@^1.0.2:
+  version "1.0.2"
+  resolved "https://registry.yarnpkg.com/is-shared-array-buffer/-/is-shared-array-buffer-1.0.2.tgz#8f259c573b60b6a32d4058a1a07430c0a7344c79"
+  integrity sha512-sqN2UDu1/0y6uvXyStCOzyhAjCSlHceFoMKJW8W9EU9cvic/QdsZ0kEU93HEy3IUEFZIiH/3w+AH/UQbPHNdhA==
+  dependencies:
+    call-bind "^1.0.2"
+
 is-ssh@^1.3.0:
   version "1.3.3"
   resolved "https://registry.yarnpkg.com/is-ssh/-/is-ssh-1.3.3.tgz#7f133285ccd7f2c2c7fc897b771b53d95a2b2c7e"
@@ -9077,6 +9165,13 @@ is-weakref@^1.0.1:
   dependencies:
     call-bind "^1.0.0"
 
+is-weakref@^1.0.2:
+  version "1.0.2"
+  resolved "https://registry.yarnpkg.com/is-weakref/-/is-weakref-1.0.2.tgz#9529f383a9338205e89765e0392efc2f100f06f2"
+  integrity sha512-qctsuLZmIQ0+vSSMfoVvyFe2+GSEvnmZ2ezTup1SBse9+twCCeial6EEi3Nc2KFcf6+qz2FBPnjXsk8xhKSaPQ==
+  dependencies:
+    call-bind "^1.0.2"
+
 is-whitespace-character@^1.0.0:
   version "1.0.4"
   resolved "https://registry.yarnpkg.com/is-whitespace-character/-/is-whitespace-character-1.0.4.tgz#0858edd94a95594c7c9dd0b5c174ec6e45ee4aa7"
@@ -11076,13 +11171,13 @@ object.getownpropertydescriptors@^2.0.3:
     define-properties "^1.1.3"
     es-abstract "^1.19.1"
 
-object.hasown@^1.1.0:
-  version "1.1.0"
-  resolved "https://registry.yarnpkg.com/object.hasown/-/object.hasown-1.1.0.tgz#7232ed266f34d197d15cac5880232f7a4790afe5"
-  integrity sha512-MhjYRfj3GBlhSkDHo6QmvgjRLXQ2zndabdf3nX0yTyZK9rPfxb6uRpAac8HXNLy1GpqWtZ81Qh4v3uOls2sRAg==
+object.hasown@^1.1.1:
+  version "1.1.1"
+  resolved "https://registry.yarnpkg.com/object.hasown/-/object.hasown-1.1.1.tgz#ad1eecc60d03f49460600430d97f23882cf592a3"
+  integrity sha512-LYLe4tivNQzq4JdaWW6WO3HMZZJWzkkH8fnI6EebWl0VZth2wL2Lovm74ep2/gZzlaTdV62JZHEqHQ2yVn8Q/A==
   dependencies:
-    define-properties "^1.1.3"
-    es-abstract "^1.19.1"
+    define-properties "^1.1.4"
+    es-abstract "^1.19.5"
 
 object.values@^1.1.5:
   version "1.1.5"
@@ -11992,11 +12087,6 @@ proxy-addr@~2.0.7:
     forwarded "0.2.0"
     ipaddr.js "1.9.1"
 
-proxy-from-env@1.0.0:
-  version "1.0.0"
-  resolved "https://registry.yarnpkg.com/proxy-from-env/-/proxy-from-env-1.0.0.tgz#33c50398f70ea7eb96d21f7b817630a55791c7ee"
-  integrity sha1-M8UDmPcOp+uW0h97gXYwpVeRx+4=
-
 psl@^1.1.28:
   version "1.8.0"
   resolved "https://registry.yarnpkg.com/psl/-/psl-1.8.0.tgz#9326f8bcfb013adcc005fdff056acce020e51c24"
@@ -12466,13 +12556,14 @@ regenerator-transform@^0.15.0:
   dependencies:
     "@babel/runtime" "^7.8.4"
 
-regexp.prototype.flags@^1.3.1:
-  version "1.3.1"
-  resolved "https://registry.yarnpkg.com/regexp.prototype.flags/-/regexp.prototype.flags-1.3.1.tgz#7ef352ae8d159e758c0eadca6f8fcb4eef07be26"
-  integrity sha512-JiBdRBq91WlY7uRJ0ds7R+dU02i6LKi8r3BuQhNXn+kmeLN+EfHhfjqMRis1zJxnlu88hq/4dx0P2OP3APRTOA==
+regexp.prototype.flags@^1.4.1, regexp.prototype.flags@^1.4.3:
+  version "1.4.3"
+  resolved "https://registry.yarnpkg.com/regexp.prototype.flags/-/regexp.prototype.flags-1.4.3.tgz#87cab30f80f66660181a3bb7bf5981a872b367ac"
+  integrity sha512-fjggEOO3slI6Wvgjwflkc4NFRCTZAu5CnNfBd5qOMYhWdn67nJBBu34/TkD++eeFmd8C9r9jfXJ27+nSiRkSUA==
   dependencies:
     call-bind "^1.0.2"
     define-properties "^1.1.3"
+    functions-have-names "^1.2.2"
 
 regexpp@^3.2.0:
   version "3.2.0"
@@ -12811,9 +12902,9 @@ rimraf@^2.6.3:
     glob "^7.1.3"
 
 rollup@^2.72.1:
-  version "2.73.0"
-  resolved "https://registry.yarnpkg.com/rollup/-/rollup-2.73.0.tgz#128fef4b333fd92d02d6929afbb6ee38d7feb32d"
-  integrity sha512-h/UngC3S4Zt28mB3g0+2YCMegT5yoftnQplwzPqGZcKvlld5e+kT/QRmJiL+qxGyZKOYpgirWGdLyEO1b0dpLQ==
+  version "2.74.1"
+  resolved "https://registry.yarnpkg.com/rollup/-/rollup-2.74.1.tgz#4fba0ff1c312cc4ee82691b154eee69a0d01929f"
+  integrity sha512-K2zW7kV8Voua5eGkbnBtWYfMIhYhT9Pel2uhBk2WO5eMee161nPze/XRfvEQPFYz7KgrCCnmh2Wy0AMFLGGmMA==
   optionalDependencies:
     fsevents "~2.3.2"
 
@@ -13483,18 +13574,18 @@ string-width@^5.0.0, string-width@^5.0.1:
     emoji-regex "^9.2.2"
     strip-ansi "^7.0.1"
 
-string.prototype.matchall@^4.0.6:
-  version "4.0.6"
-  resolved "https://registry.yarnpkg.com/string.prototype.matchall/-/string.prototype.matchall-4.0.6.tgz#5abb5dabc94c7b0ea2380f65ba610b3a544b15fa"
-  integrity sha512-6WgDX8HmQqvEd7J+G6VtAahhsQIssiZ8zl7zKh1VDMFyL3hRTJP4FTNA3RbIp2TOQ9AYNDcc7e3fH0Qbup+DBg==
+string.prototype.matchall@^4.0.7:
+  version "4.0.7"
+  resolved "https://registry.yarnpkg.com/string.prototype.matchall/-/string.prototype.matchall-4.0.7.tgz#8e6ecb0d8a1fb1fda470d81acecb2dba057a481d"
+  integrity sha512-f48okCX7JiwVi1NXCVWcFnZgADDC/n2vePlQ/KUCNqCikLLilQvwjMO8+BHVKvgzH0JB0J9LEPgxOGT02RoETg==
   dependencies:
     call-bind "^1.0.2"
     define-properties "^1.1.3"
     es-abstract "^1.19.1"
     get-intrinsic "^1.1.1"
-    has-symbols "^1.0.2"
+    has-symbols "^1.0.3"
     internal-slot "^1.0.3"
-    regexp.prototype.flags "^1.3.1"
+    regexp.prototype.flags "^1.4.1"
     side-channel "^1.0.4"
 
 string.prototype.trimend@^1.0.4:
@@ -13505,6 +13596,15 @@ string.prototype.trimend@^1.0.4:
     call-bind "^1.0.2"
     define-properties "^1.1.3"
 
+string.prototype.trimend@^1.0.5:
+  version "1.0.5"
+  resolved "https://registry.yarnpkg.com/string.prototype.trimend/-/string.prototype.trimend-1.0.5.tgz#914a65baaab25fbdd4ee291ca7dde57e869cb8d0"
+  integrity sha512-I7RGvmjV4pJ7O3kdf+LXFpVfdNOxtCW/2C8f6jNiW4+PQchwxkCDzlk1/7p+Wl4bqFIZeF47qAHXLuHHWKAxog==
+  dependencies:
+    call-bind "^1.0.2"
+    define-properties "^1.1.4"
+    es-abstract "^1.19.5"
+
 string.prototype.trimstart@^1.0.4:
   version "1.0.4"
   resolved "https://registry.yarnpkg.com/string.prototype.trimstart/-/string.prototype.trimstart-1.0.4.tgz#b36399af4ab2999b4c9c648bd7a3fb2bb26feeed"
@@ -13513,6 +13613,15 @@ string.prototype.trimstart@^1.0.4:
     call-bind "^1.0.2"
     define-properties "^1.1.3"
 
+string.prototype.trimstart@^1.0.5:
+  version "1.0.5"
+  resolved "https://registry.yarnpkg.com/string.prototype.trimstart/-/string.prototype.trimstart-1.0.5.tgz#5466d93ba58cfa2134839f81d7f42437e8c01fef"
+  integrity sha512-THx16TJCGlsN0o6dl2o6ncWUsdgnLRSA23rRE5pyGBw/mLr3Ej/R2LaqCtgP8VNMGZsvMWnf9ooZPyY2bHvUFg==
+  dependencies:
+    call-bind "^1.0.2"
+    define-properties "^1.1.4"
+    es-abstract "^1.19.5"
+
 string_decoder@^1.1.1:
   version "1.3.0"
   resolved "https://registry.yarnpkg.com/string_decoder/-/string_decoder-1.3.0.tgz#42f114594a46cf1a8e30b0a84f56c78c3edac21e"
@@ -14143,6 +14252,16 @@ unbox-primitive@^1.0.1:
     has-symbols "^1.0.2"
     which-boxed-primitive "^1.0.2"
 
+unbox-primitive@^1.0.2:
+  version "1.0.2"
+  resolved "https://registry.yarnpkg.com/unbox-primitive/-/unbox-primitive-1.0.2.tgz#29032021057d5e6cdbd08c5129c226dff8ed6f9e"
+  integrity sha512-61pPlCD9h51VoreyJ0BReideM3MDKMKnh6+V9L08331ipq6Q8OFXZYiqP6n/tbHx4s5I9uRhcye6BrbkizkBDw==
+  dependencies:
+    call-bind "^1.0.2"
+    has-bigints "^1.0.2"
+    has-symbols "^1.0.3"
+    which-boxed-primitive "^1.0.2"
+
 unherit@^1.0.4:
   version "1.1.3"
   resolved "https://registry.yarnpkg.com/unherit/-/unherit-1.1.3.tgz#6c9b503f2b41b262330c80e91c8614abdaa69c22"