typescript-eslint · JoshuaKGoldberg · Mar 17, 2025 · Feb 3, 2025 · Feb 3, 2025 · Feb 3, 2025
diff --git a/eslint.config.mjs b/eslint.config.mjs
@@ -5,6 +5,7 @@ import { FlatCompat } from '@eslint/eslintrc';
 import eslint from '@eslint/js';
 import eslintCommentsPlugin from '@eslint-community/eslint-plugin-eslint-comments/configs';
 import tseslintInternalPlugin from '@typescript-eslint/eslint-plugin-internal';
+import vitestPlugin from '@vitest/eslint-plugin';
 import eslintPluginPlugin from 'eslint-plugin-eslint-plugin';
 import importPlugin from 'eslint-plugin-import';
 import jestPlugin from 'eslint-plugin-jest';
@@ -28,6 +29,10 @@ const restrictNamedDeclarations = {
   selector: 'ExportNamedDeclaration[declaration=null][source=null]',
 };
 
+const vitestFiles = [
+  'packages/eslint-plugin-internal/tests/**/*.test.{ts,tsx,cts,mts}',
+];
+
 export default tseslint.config(
   // register all of the plugins up-front
   {
@@ -43,6 +48,7 @@ export default tseslint.config(
       // @ts-expect-error -- https://github.com/jsx-eslint/eslint-plugin-jsx-a11y/pull/1038
       ['jsx-a11y']: jsxA11yPlugin.flatConfigs.recommended.plugins['jsx-a11y'],
       ['perfectionist']: perfectionistPlugin,
+      ['vitest']: vitestPlugin,
       // https://github.com/facebook/react/issues/28313
       ['react']: reactPlugin,
       // @ts-expect-error -- Temporary types incompatibility pending flat config support
@@ -361,12 +367,22 @@ export default tseslint.config(
   // define the jest globals for all test files
   {
     files: ['packages/*/tests/**/*.{ts,tsx,cts,mts}'],
+    ignores: vitestFiles,
     languageOptions: {
       globals: {
         ...jestPlugin.environments.globals.globals,
       },
     },
   },
+  // define the vitest globals for all test files
+  {
+    files: vitestFiles,
+    languageOptions: {
+      globals: {
+        ...vitestPlugin.environments.env.globals,
+      },
+    },
+  },
   // test file specific configuration
   {
     files: [
@@ -376,6 +392,7 @@ export default tseslint.config(
       'packages/integration-tests/tools/integration-test-base.ts',
       'packages/integration-tests/tools/pack-packages.ts',
     ],
+    ignores: vitestFiles,
     rules: {
       '@typescript-eslint/no-empty-function': [
         'error',
@@ -402,6 +419,34 @@ export default tseslint.config(
       'jest/valid-expect': 'error',
     },
   },
+  // test file specific configuration
+  {
+    files: vitestFiles,
+    rules: {
+      '@typescript-eslint/no-empty-function': [
+        'error',
+        { allow: ['arrowFunctions'] },
+      ],
+      '@typescript-eslint/no-non-null-assertion': 'off',
+      '@typescript-eslint/no-unsafe-assignment': 'off',
+      '@typescript-eslint/no-unsafe-call': 'off',
+      '@typescript-eslint/no-unsafe-member-access': 'off',
+      '@typescript-eslint/no-unsafe-return': 'off',
+      'vitest/no-alias-methods': 'error',
+      'vitest/no-disabled-tests': 'error',
+      'vitest/no-focused-tests': 'error',
+      'vitest/no-identical-title': 'error',
+      'vitest/no-test-prefixes': 'error',
+      'vitest/no-test-return-statement': 'error',
+      'vitest/prefer-each': 'error',
+      'vitest/prefer-spy-on': 'error',
+      'vitest/prefer-to-be': 'error',
+      'vitest/prefer-to-contain': 'error',
+      'vitest/prefer-to-have-length': 'error',
+      'vitest/valid-expect': 'error',
+    },
+    settings: { vitest: { typecheck: true } },
+  },
   // plugin rule tests
   {
     files: [
@@ -430,7 +475,13 @@ export default tseslint.config(
     },
   },
   {
-    files: ['eslint.config.{js,cjs,mjs}', 'knip.ts', 'packages/*/src/index.ts'],
+    files: [
+      'eslint.config.{js,cjs,mjs}',
+      'knip.ts',
+      'packages/*/src/index.ts',
+      'vitest.config.mts',
+      'packages/*/vitest.config.mts',
+    ],
     rules: {
       // requirement
       'import/no-default-export': 'off',

diff --git a/knip.ts b/knip.ts
@@ -11,6 +11,9 @@ export default {
     types: 'off',
     unresolved: 'off',
   },
+  vitest: {
+    config: ['vitest.config.mts', 'packages/*/vitest.config.mts'],
+  },
   workspaces: {
     '.': {
       entry: ['tools/release/changelog-renderer.js', 'tools/scripts/**/*.mts'],

diff --git a/nx.json b/nx.json
@@ -14,6 +14,28 @@
           "configName": "tsconfig.build.json"
         }
       }
+    },
+    {
+      "plugin": "@nx/vite/plugin",
+      "include": ["packages/*"],
+      "options": {
+        "buildTargetName": "vite:build",
+        "testTargetName": "test",
+        "serveTargetName": "serve",
+        "devTargetName": "dev",
+        "previewTargetName": "preview",
+        "serveStaticTargetName": "serve-static",
+        "typecheckTargetName": "vite:typecheck",
+        "buildDepsTargetName": "vite:build-deps",
+        "watchDepsTargetName": "vite:watch-deps"
+      }
+    },
+    {
+      "plugin": "@nx/jest/plugin",
+      "include": ["packages/*"],
+      "options": {
+        "targetName": "test"
+      }
     }
   ],
   "release": {
@@ -40,19 +62,19 @@
     "build": {
       "dependsOn": ["^build"],
       "inputs": ["production", "^production"],
+      "outputs": ["{projectRoot}/dist"],
+      "options": {
+        "cwd": "{projectRoot}"
+      },
       "cache": true
     },
     "test": {
-      "inputs": [
-        "default",
-        "^production",
-        "{workspaceRoot}/jest.config.js",
-        "{workspaceRoot}/jest.config.base.js"
-      ],
+      "dependsOn": ["^build"],
       "outputs": ["{projectRoot}/coverage"],
       "cache": true
     },
     "@nx/jest:jest": {
+      "dependsOn": ["^build"],
       "inputs": [
         "default",
         "^production",
@@ -72,7 +94,25 @@
         }
       }
     },
+    "@nx/vite:test": {
+      "dependsOn": ["^build"],
+      "inputs": [
+        "default",
+        "^production",
+        "{workspaceRoot}/vitest.config.mts",
+        "{workspaceRoot}/vitest.config.base.mts",
+        "{projectRoot}/vitest.config.mts"
+      ],
+      "outputs": ["{options.reportsDirectory}"],
+      "cache": true,
+      "options": {
+        "config": "{projectRoot}/vitest.config.mts",
+        "watch": false,
+        "reportsDirectory": "{projectRoot}/coverage"
+      }
+    },
     "lint": {
+      "executor": "@nx/eslint:lint",
       "dependsOn": [
         "eslint-plugin:build",
         "eslint-plugin-internal:build",
@@ -87,6 +127,12 @@
           "transitive": false
         }
       ],
+      "outputs": ["{options.outputFile}"],
+      "cache": true
+    },
+    "typecheck": {
+      "dependsOn": ["types:copy-ast-spec"],
+      "outputs": ["{workspaceRoot}/dist/out-tsc/{projectRoot}"],
       "cache": true
     }
   },
@@ -110,6 +156,7 @@
       "!{projectRoot}/**/?(*.)+(test).[jt]s?(x)?(.snap)",
       "!{projectRoot}/tsconfig.spec.json",
       "!{projectRoot}/jest.config.[jt]s",
+      "!{projectRoot}/vitest.config.m[jt]s",
       "!{projectRoot}/src/test-setup.[jt]s"
     ]
   }

diff --git a/package.json b/package.json
@@ -66,6 +66,7 @@
     "@nx/devkit": "20.4.5",
     "@nx/eslint": "20.4.5",
     "@nx/jest": "20.4.5",
+    "@nx/vite": "20.4.5",
     "@nx/workspace": "20.4.5",
     "@swc/core": "^1.4.12",
     "@swc/jest": "^0.2.36",
@@ -88,6 +89,8 @@
     "@typescript-eslint/types": "workspace:^",
     "@typescript-eslint/typescript-estree": "workspace:^",
     "@typescript-eslint/utils": "workspace:^",
+    "@vitest/coverage-v8": "^3.0.8",
+    "@vitest/eslint-plugin": "^1.1.37",
     "console-fail-test": "^0.5.0",
     "cross-fetch": "^4.0.0",
     "cspell": "^8.15.2",
@@ -123,6 +126,8 @@
     "tsx": "*",
     "typescript": ">=4.8.4 <5.9.0",
     "typescript-eslint": "workspace:^",
+    "vite": "^6.2.2",
+    "vitest": "^3.0.8",
     "yargs": "17.7.2"
   },
   "resolutions": {

diff --git a/packages/ast-spec/project.json b/packages/ast-spec/project.json
@@ -15,6 +15,9 @@
     "lint": {
       "executor": "@nx/eslint:lint",
       "outputs": ["{options.outputFile}"]
+    },
+    "typecheck": {
+      "dependsOn": ["typescript-estree:build"]
     }
   }
 }
diff --git a/packages/eslint-plugin-internal/jest.config.js b/packages/eslint-plugin-internal/jest.config.js
diff --git a/packages/eslint-plugin-internal/package.json b/packages/eslint-plugin-internal/package.json
@@ -16,10 +16,10 @@
   "scripts": {
     "build": "npx tsc -b tsconfig.build.json",
     "clean": "npx tsc -b tsconfig.build.json --clean",
-    "postclean": "rimraf dist && rimraf coverage",
+    "postclean": "rimraf dist/ coverage/",
     "format": "prettier --write \"./**/*.{ts,mts,cts,tsx,js,mjs,cjs,jsx,json,md,css}\" --ignore-path ../../.prettierignore",
     "lint": "npx nx lint",
-    "test": "jest",
+    "test": "vitest --run --config=$INIT_CWD/vitest.config.mts",
     "check-types": "npx nx typecheck"
   },
   "dependencies": {
@@ -31,8 +31,8 @@
     "prettier": "^3.2.5"
   },
   "devDependencies": {
-    "@jest/types": "29.6.3",
-    "jest": "29.7.0",
-    "rimraf": "*"
+    "@vitest/coverage-v8": "^3.0.8",
+    "rimraf": "*",
+    "vitest": "^3.0.8"
   }
 }
diff --git a/packages/eslint-plugin-internal/project.json b/packages/eslint-plugin-internal/project.json
@@ -1,12 +1,16 @@
 {
   "name": "eslint-plugin-internal",
   "$schema": "../../node_modules/nx/schemas/project-schema.json",
-  "type": "library",
-  "implicitDependencies": [],
+  "projectType": "library",
+  "root": "packages/eslint-plugin-internal",
+  "sourceRoot": "packages/eslint-plugin-internal/src",
   "targets": {
     "lint": {
       "executor": "@nx/eslint:lint",
       "outputs": ["{options.outputFile}"]
+    },
+    "test": {
+      "executor": "@nx/vite:test"
     }
   }
 }
diff --git a/packages/eslint-plugin-internal/tsconfig.build.json b/packages/eslint-plugin-internal/tsconfig.build.json
@@ -9,7 +9,7 @@
     "types": ["node"]
   },
   "include": ["src/**/*.ts", "index.d.ts"],
-  "exclude": ["jest.config.js", "src/**/*.spec.ts", "src/**/*.test.ts"],
+  "exclude": ["vitest.config.mts", "src/**/*.spec.ts", "src/**/*.test.ts"],
   "references": [
     {
       "path": "../type-utils/tsconfig.build.json"

diff --git a/packages/eslint-plugin-internal/tsconfig.spec.json b/packages/eslint-plugin-internal/tsconfig.spec.json
@@ -3,10 +3,12 @@
   "compilerOptions": {
     "outDir": "../../dist/out-tsc/packages/eslint-plugin-internal",
     "module": "NodeNext",
-    "types": ["jest", "node"]
+    "resolveJsonModule": true,
+    "types": ["node", "vitest/globals", "vitest/importMeta"]
   },
   "include": [
-    "jest.config.js",
+    "vitest.config.mts",
+    "package.json",
     "src/**/*.test.ts",
     "src/**/*.spec.ts",
     "src/**/*.d.ts",
@@ -16,6 +18,9 @@
   "references": [
     {
       "path": "./tsconfig.build.json"
+    },
+    {
+      "path": "../../tsconfig.spec.json"
     }
   ]
 }
diff --git a/packages/eslint-plugin-internal/vitest.config.mts b/packages/eslint-plugin-internal/vitest.config.mts
@@ -0,0 +1,21 @@
+import * as path from 'node:path';
+import { defineProject, mergeConfig } from 'vitest/config';
+
+import { vitestBaseConfig } from '../../vitest.config.base.mjs';
+import packageJson from './package.json' with { type: 'json' };
+
+const vitestConfig = mergeConfig(
+  vitestBaseConfig,
+
+  defineProject({
+    root: import.meta.dirname,
+
+    test: {
+      dir: path.join(import.meta.dirname, 'tests'),
+      name: packageJson.name.replace('@typescript-eslint/', ''),
+      root: import.meta.dirname,
+    },
+  }),
+);
+
+export default vitestConfig;
diff --git a/project.json b/project.json
@@ -4,7 +4,9 @@
   "// These targets are used for repo level utils and checking repo files which do not belong to specific published packages": {},
   "targets": {
     "typecheck": {
-      "command": "tsc -b ./tsconfig.repo-config-files.json"
+      "command": "tsc -b ./tsconfig.repo-config-files.json",
+      "dependsOn": ["types:copy-ast-spec"],
+      "outputs": ["{workspaceRoot}/dist/out-tsc/root"]
     },
     "lint": {
       "command": "eslint . --ignore-pattern=packages --cache"

diff --git a/tsconfig.repo-config-files.json b/tsconfig.repo-config-files.json
@@ -3,7 +3,6 @@
   "compilerOptions": {
     "outDir": "dist/out-tsc/root/eslint",
     "types": ["@types/node"],
-    "noEmit": true,
     "allowJs": true,
     "allowImportingTsExtensions": true
   },
@@ -17,5 +16,13 @@
     "jest.preset.js",
     "knip.ts",
     ".github/**/*.js"
+  ],
+  "references": [
+    {
+      "path": "./packages/typescript-eslint/tsconfig.build.json"
+    },
+    {
+      "path": "./tsconfig.spec.json"
+    }
   ]
 }