typescript-eslint · JoshuaKGoldberg · Apr 11, 2025 · Feb 3, 2025 · Feb 3, 2025 · Feb 3, 2025
diff --git a/eslint.config.mjs b/eslint.config.mjs
@@ -33,6 +33,8 @@ const vitestFiles = [
   'packages/eslint-plugin-internal/tests/**/*.test.{ts,tsx,cts,mts}',
   'packages/typescript-eslint/tests/**/*.test.{ts,tsx,cts,mts}',
   'packages/visitor-keys/tests/**/*.test.{ts,tsx,cts,mts}',
+  'packages/parser/tests/lib/**/*.test.{ts,tsx,cts,mts}',
+  'packages/parser/tests/test-utils/**/*.{ts,tsx,cts,mts}',
 ];
 
 export default tseslint.config(
@@ -379,18 +381,13 @@ export default tseslint.config(
   // define the vitest globals for all test files
   {
     files: vitestFiles,
-    languageOptions: {
-      globals: {
-        ...vitestPlugin.environments.env.globals,
-      },
-    },
+    ...vitestPlugin.configs.env,
   },
   // test file specific configuration
   {
     files: [
       'packages/*/tests/**/*.test.{ts,tsx,cts,mts}',
       'packages/*/tests/**/test.{ts,tsx,cts,mts}',
-      'packages/parser/tests/**/*.{ts,tsx,cts,mts}',
       'packages/integration-tests/tools/integration-test-base.ts',
       'packages/integration-tests/tools/pack-packages.ts',
     ],
@@ -440,6 +437,7 @@ export default tseslint.config(
       'vitest/no-identical-title': 'error',
       'vitest/no-test-prefixes': 'error',
       'vitest/no-test-return-statement': 'error',
+      'vitest/prefer-describe-function-title': 'error',
       'vitest/prefer-each': 'error',
       'vitest/prefer-spy-on': 'error',
       'vitest/prefer-to-be': 'error',

diff --git a/knip.ts b/knip.ts
@@ -65,6 +65,11 @@ export default {
     },
     'packages/parser': {
       ignore: ['tests/fixtures/**'],
+
+      vitest: {
+        config: ['vitest.config.mts'],
+        entry: ['tests/lib/**/*.{bench,test,test-d}.?(c|m)ts?(x)'],
+      },
     },
     'packages/rule-tester': {
       ignore: ['typings/eslint.d.ts'],

diff --git a/package.json b/package.json
@@ -90,7 +90,7 @@
     "@typescript-eslint/typescript-estree": "workspace:^",
     "@typescript-eslint/utils": "workspace:^",
     "@vitest/coverage-v8": "^3.1.1",
-    "@vitest/eslint-plugin": "^1.1.39",
+    "@vitest/eslint-plugin": "^1.1.42",
     "console-fail-test": "^0.5.0",
     "cross-fetch": "^4.0.0",
     "cspell": "^8.15.2",
@@ -126,7 +126,7 @@
     "tsx": "*",
     "typescript": ">=4.8.4 <5.9.0",
     "typescript-eslint": "workspace:^",
-    "vite": "^6.2.5",
+    "vite": "^6.2.6",
     "vitest": "^3.1.1",
     "yargs": "17.7.2"
   },

diff --git a/packages/parser/jest.config.js b/packages/parser/jest.config.js
diff --git a/packages/parser/package.json b/packages/parser/package.json
@@ -43,10 +43,10 @@
     "build": "tsc -b tsconfig.build.json",
     "postbuild": "downlevel-dts dist _ts4.3/dist --to=4.3",
     "clean": "tsc -b tsconfig.build.json --clean",
-    "postclean": "rimraf dist && rimraf _ts4.3 && rimraf coverage",
+    "postclean": "rimraf dist/ _ts4.3/ 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"
   },
   "peerDependencies": {
@@ -61,13 +61,13 @@
     "debug": "^4.3.4"
   },
   "devDependencies": {
-    "@jest/types": "29.6.3",
+    "@vitest/coverage-v8": "^3.1.1",
     "downlevel-dts": "*",
     "glob": "*",
-    "jest": "29.7.0",
     "prettier": "^3.2.5",
     "rimraf": "*",
-    "typescript": "*"
+    "typescript": "*",
+    "vitest": "^3.1.1"
   },
   "funding": {
     "type": "opencollective",

diff --git a/packages/parser/project.json b/packages/parser/project.json
@@ -1,12 +1,16 @@
 {
   "name": "parser",
   "$schema": "../../node_modules/nx/schemas/project-schema.json",
-  "type": "library",
-  "implicitDependencies": [],
+  "projectType": "library",
+  "root": "packages/parser",
+  "sourceRoot": "packages/parser/src",
   "targets": {
     "lint": {
       "executor": "@nx/eslint:lint",
       "outputs": ["{options.outputFile}"]
+    },
+    "test": {
+      "executor": "@nx/vite:test"
     }
   }
 }
diff --git a/packages/parser/tests/lib/__snapshots__/services.test.ts.snap b/packages/parser/tests/lib/__snapshots__/services.test.ts.snap
@@ -1,6 +1,6 @@
-// Jest Snapshot v1, https://goo.gl/fbAQLP
+// Vitest Snapshot v1, https://vitest.dev/guide/snapshot.html
 
-exports[`services fixtures/isolated-file.src 1`] = `
+exports[`services > fixtures/isolated-file.src 1`] = `
 {
   "body": [
     {

diff --git a/packages/parser/tests/lib/parser.test.ts b/packages/parser/tests/lib/parser.test.ts
@@ -9,7 +9,7 @@ import { parse, parseForESLint } from '../../src/parser';
 
 describe('parser', () => {
   beforeEach(() => {
-    jest.clearAllMocks();
+    vi.clearAllMocks();
   });
 
   it('parse() should return just the AST from parseForESLint()', () => {
@@ -24,7 +24,7 @@ describe('parser', () => {
 
   it('parseAndGenerateServices() should be called with options', () => {
     const code = 'const valid = true;';
-    const spy = jest.spyOn(typescriptESTree, 'parseAndGenerateServices');
+    const spy = vi.spyOn(typescriptESTree, 'parseAndGenerateServices');
     const config: ParserOptions = {
       ecmaFeatures: {
         globalReturn: false,
@@ -36,11 +36,10 @@ describe('parser', () => {
       extraFileExtensions: ['.foo'],
       filePath: './isolated-file.src.ts',
       project: 'tsconfig.json',
-      tsconfigRootDir: path.resolve(__dirname, '../fixtures/services'),
+      tsconfigRootDir: path.join(__dirname, '..', 'fixtures', 'services'),
     };
     parseForESLint(code, config);
-    expect(spy).toHaveBeenCalledTimes(1);
-    expect(spy).toHaveBeenLastCalledWith(code, {
+    expect(spy).toHaveBeenCalledExactlyOnceWith(code, {
       comment: true,
       jsx: false,
       loc: true,
@@ -52,9 +51,9 @@ describe('parser', () => {
 
   it('overrides `errorOnTypeScriptSyntacticAndSemanticIssues: false` when provided `errorOnTypeScriptSyntacticAndSemanticIssues: false`', () => {
     const code = 'const valid = true;';
-    const spy = jest.spyOn(typescriptESTree, 'parseAndGenerateServices');
+    const spy = vi.spyOn(typescriptESTree, 'parseAndGenerateServices');
     parseForESLint(code, { errorOnTypeScriptSyntacticAndSemanticIssues: true });
-    expect(spy).toHaveBeenCalledWith(code, {
+    expect(spy).toHaveBeenCalledExactlyOnceWith(code, {
       comment: true,
       ecmaFeatures: {},
       errorOnTypeScriptSyntacticAndSemanticIssues: false,
@@ -68,9 +67,9 @@ describe('parser', () => {
 
   it('sets `loggerFn: false` on typescript-estree when provided `warnOnUnsupportedTypeScriptVersion: false`', () => {
     const code = 'const valid = true;';
-    const spy = jest.spyOn(typescriptESTree, 'parseAndGenerateServices');
+    const spy = vi.spyOn(typescriptESTree, 'parseAndGenerateServices');
     parseForESLint(code, { warnOnUnsupportedTypeScriptVersion: false });
-    expect(spy).toHaveBeenCalledWith(code, {
+    expect(spy).toHaveBeenCalledExactlyOnceWith(code, {
       comment: true,
       ecmaFeatures: {},
       errorOnTypeScriptSyntacticAndSemanticIssues: false,
@@ -86,9 +85,9 @@ describe('parser', () => {
 
   it('sets `loggerFn: false` on typescript-estree when provided `warnOnUnsupportedTypeScriptVersion: true`', () => {
     const code = 'const valid = true;';
-    const spy = jest.spyOn(typescriptESTree, 'parseAndGenerateServices');
+    const spy = vi.spyOn(typescriptESTree, 'parseAndGenerateServices');
     parseForESLint(code, { warnOnUnsupportedTypeScriptVersion: true });
-    expect(spy).toHaveBeenCalledWith(code, {
+    expect(spy).toHaveBeenCalledExactlyOnceWith(code, {
       comment: true,
       ecmaFeatures: {},
       errorOnTypeScriptSyntacticAndSemanticIssues: false,
@@ -103,18 +102,17 @@ describe('parser', () => {
 
   it('should call analyze() with inferred analyze options when no analyze options are provided', () => {
     const code = 'const valid = true;';
-    const spy = jest.spyOn(scopeManager, 'analyze');
+    const spy = vi.spyOn(scopeManager, 'analyze');
     const config: ParserOptions = {
       errorOnTypeScriptSyntacticAndSemanticIssues: false,
       filePath: 'isolated-file.src.ts',
       project: 'tsconfig.json',
-      tsconfigRootDir: path.join(__dirname, '../fixtures/services'),
+      tsconfigRootDir: path.join(__dirname, '..', 'fixtures', 'services'),
     };
 
     parseForESLint(code, config);
 
-    expect(spy).toHaveBeenCalledTimes(1);
-    expect(spy).toHaveBeenLastCalledWith(expect.anything(), {
+    expect(spy).toHaveBeenCalledExactlyOnceWith(expect.anything(), {
       globalReturn: undefined,
       jsxFragmentName: undefined,
       jsxPragma: undefined,
@@ -123,7 +121,7 @@ describe('parser', () => {
     });
   });
 
-  it.each([
+  it.for([
     ['esnext.full', ScriptTarget.ESNext],
     ['es2022.full', ScriptTarget.ES2022],
     ['es2021.full', ScriptTarget.ES2021],
@@ -135,32 +133,32 @@ describe('parser', () => {
     ['es6', ScriptTarget.ES2015],
     ['lib', ScriptTarget.ES5],
     ['lib', undefined],
-  ])(
+  ] as const)(
     'calls analyze() with `lib: [%s]` when the compiler options target is %s',
-    (lib, target) => {
+    ([lib, target], { expect }) => {
       const code = 'const valid = true;';
-      const spy = jest.spyOn(scopeManager, 'analyze');
+      const spy = vi.spyOn(scopeManager, 'analyze');
       const config: ParserOptions = {
         filePath: 'isolated-file.src.ts',
         project: 'tsconfig.json',
-        tsconfigRootDir: path.join(__dirname, '../fixtures/services'),
+        tsconfigRootDir: path.join(__dirname, '..', 'fixtures', 'services'),
       };
 
-      jest
-        .spyOn(typescriptESTree, 'parseAndGenerateServices')
-        .mockReturnValueOnce({
-          ast: {},
-          services: {
-            program: {
-              getCompilerOptions: () => ({ target }),
-            },
+      vi.spyOn(
+        typescriptESTree,
+        'parseAndGenerateServices',
+      ).mockReturnValueOnce({
+        ast: {},
+        services: {
+          program: {
+            getCompilerOptions: () => ({ target }),
           },
-        } as typescriptESTree.ParseAndGenerateServicesResult<typescriptESTree.TSESTreeOptions>);
+        },
+      } as typescriptESTree.ParseAndGenerateServicesResult<typescriptESTree.TSESTreeOptions>);
 
       parseForESLint(code, config);
 
-      expect(spy).toHaveBeenCalledTimes(1);
-      expect(spy).toHaveBeenLastCalledWith(
+      expect(spy).toHaveBeenCalledExactlyOnceWith(
         expect.anything(),
         expect.objectContaining({
           lib: [lib],
@@ -171,7 +169,7 @@ describe('parser', () => {
 
   it('calls analyze() with the provided analyze options when analyze options are provided', () => {
     const code = 'const valid = true;';
-    const spy = jest.spyOn(scopeManager, 'analyze');
+    const spy = vi.spyOn(scopeManager, 'analyze');
     const config: ParserOptions = {
       ecmaFeatures: {
         globalReturn: false,
@@ -187,13 +185,12 @@ describe('parser', () => {
       extraFileExtensions: ['.foo'],
       filePath: 'isolated-file.src.ts',
       project: 'tsconfig.json',
-      tsconfigRootDir: path.join(__dirname, '../fixtures/services'),
+      tsconfigRootDir: path.join(__dirname, '..', 'fixtures', 'services'),
     };
 
     parseForESLint(code, config);
 
-    expect(spy).toHaveBeenCalledTimes(1);
-    expect(spy).toHaveBeenLastCalledWith(expect.anything(), {
+    expect(spy).toHaveBeenCalledExactlyOnceWith(expect.anything(), {
       globalReturn: false,
       jsxFragmentName: 'Bar',
       jsxPragma: 'Foo',

diff --git a/packages/parser/tests/lib/services.test.ts b/packages/parser/tests/lib/services.test.ts
@@ -1,6 +1,6 @@
 import { createProgram } from '@typescript-eslint/typescript-estree';
 import * as glob from 'glob';
-import fs from 'node:fs';
+import fs from 'node:fs/promises';
 import path from 'node:path';
 
 import type { ParserOptions } from '../../src/parser';
@@ -15,7 +15,14 @@ import {
 // Setup
 //------------------------------------------------------------------------------
 
-const FIXTURES_DIR = './tests/fixtures/services';
+const FIXTURES_DIR = path.join(
+  __dirname,
+  '..',
+  '..',
+  'tests',
+  'fixtures',
+  'services',
+);
 const testFiles = glob.sync(`**/*.src.ts`, {
   cwd: FIXTURES_DIR,
 });
@@ -32,18 +39,19 @@ function createConfig(filename: string): ParserOptions {
 // Tests
 //------------------------------------------------------------------------------
 
-describe('services', () => {
-  const program = createProgram(path.resolve(FIXTURES_DIR, 'tsconfig.json'));
-  testFiles.forEach(filename => {
-    const code = fs.readFileSync(path.join(FIXTURES_DIR, filename), 'utf8');
-    const config = createConfig(filename);
-    const snapshotName = formatSnapshotName(filename, FIXTURES_DIR, '.ts');
-    it(snapshotName, createSnapshotTestBlock(code, config));
-    it(`${snapshotName} services`, () => {
-      testServices(code, config);
-    });
-    it(`${snapshotName} services with provided program`, () => {
-      testServices(code, { ...config, program });
-    });
+const program = createProgram(path.resolve(FIXTURES_DIR, 'tsconfig.json'));
+
+describe.for(testFiles)('services', async filename => {
+  const code = await fs.readFile(path.join(FIXTURES_DIR, filename), {
+    encoding: 'utf-8',
+  });
+  const config = createConfig(filename);
+  const snapshotName = formatSnapshotName(filename, FIXTURES_DIR, '.ts');
+  it(snapshotName, createSnapshotTestBlock(code, config));
+  it(`${snapshotName} services`, () => {
+    testServices(code, config);
+  });
+  it(`${snapshotName} services with provided program`, () => {
+    testServices(code, { ...config, program });
   });
 });