feat: [4.7] support new extensions (#5027)

.cspell.json

@@ -114,7 +114,7 @@
   ],
   "overrides": [
     {
-      "filename": "**/*.{ts,js,tsx,jsx}",
+      "filename": "**/*.{ts,mts,cts,js,cjs,mjs,tsx,jsx}",
       "ignoreRegExpList": ["/@[a-z]+/", "/#(end)?region/"],
       "includeRegExpList": [
         "/\\/\\*[\\s\\S]*?\\*\\/|([^\\\\:]|^)\\/\\/.*$/",

.lintstagedrc

@@ -1,5 +1,5 @@
 {
-  "*.{ts,js,json,md}": [
+  "*.{ts,mts,cts,tsx,js,mjs,cjs,jsx,json,md,css}": [
     "prettier --write"
   ]
 }

docs/linting/README.md

@@ -85,27 +85,27 @@ With that configured, open a terminal to the root of your project, and run the f
 <TabItem value="npm">
 
 ```bash
-npx eslint . --ext .js,.jsx,.ts,.tsx
+npx eslint .
 ```
 
 </TabItem>
 <TabItem value="Yarn">
 
 ```bash
-yarn eslint . --ext .js,.jsx,.ts,.tsx
+yarn eslint .
 ```
 
 </TabItem>
 </Tabs>
 
-That's it - ESLint will lint all `.js`, `.jsx`, `.ts`, and `.tsx` files within the current folder, and will output the results to your terminal.
+That's it - ESLint will lint all TypeScript compatible files within the current folder, and will output the results to your terminal.
 
 You are also recommended to add an npm script in your package.json, so you don't have to repeat the same command every time you run ESLint.
 
 ```json title="package.json"
 {
   "scripts": {
-    "lint": "eslint . --ext .js,.jsx,.ts,.tsx"
+    "lint": "eslint ."
   }
 }
 ```
@@ -116,6 +116,10 @@ This way, you can invoke the `lint` script directly:
 npm run lint
 ```
 
+:::note
+If you use non-standard file extensions, you will need to explicitly tell ESLint to lint those extensions using the [`--ext` flag](https://eslint.org/docs/user-guide/command-line-interface#--ext)
+:::
+
 You can also get results in realtime inside most IDEs via a plugin - search your IDE's extension store.
 
 ## Next Steps

docs/linting/TROUBLESHOOTING.md

@@ -119,17 +119,20 @@ As of our v4.0.0 release, this also applies to types.
 If you use global types from a 3rd party package (i.e. anything from an `@types` package), then you will have to configure ESLint appropriately to define these global types.
 For example; the `JSX` namespace from `@types/react` is a global 3rd party type that you must define in your ESLint config.
 
-Note, that for a mixed project including JavaScript and TypeScript, the `no-undef` rule (like any role) can be turned off for TypeScript files alone by adding an `overrides` section to .eslintrc.json:
-
-```json
-    "overrides": [
-        {
-            "files": ["*.ts"],
-            "rules": {
-                "no-undef": "off"
-            }
-        }
-    ]
+Note, that for a mixed project including JavaScript and TypeScript, the `no-undef` rule (like any rule) can be turned off for TypeScript files alone by adding an `overrides` section to `.eslintrc.cjs`:
+
+```js title=".eslintrc.cjs"
+module.exports = {
+  // ... the rest of your config ...
+  overrides: [
+    {
+      files: ['*.ts', '*.mts', '*.cts', '*.tsx'],
+      rules: {
+        'no-undef': 'off',
+      },
+    },
+  ],
+};
 ```
 
 If you choose to leave on the ESLint `no-undef` lint rule, you can [manually define the set of allowed `globals` in your ESLint config](https://eslint.org/docs/user-guide/configuring/language-options#specifying-globals), and/or you can use one of the [pre-defined environment (`env`) configurations](https://eslint.org/docs/user-guide/configuring/language-options#specifying-environments).
@@ -206,7 +209,7 @@ Instead of using this plugin, we recommend using prettier's `--list-different` f
 For example, our CI is setup to run the following command automatically, which blocks PRs that have not been formatted:
 
 ```bash npm2yarn
-npm run prettier --list-different \"./**/*.{ts,js,json,md}\"
+npm run prettier --list-different \"./**/*.{ts,mts,cts,tsx,js,mjs,cjs,jsx,json,md,css}\"
 ```
 
 ### `eslint-plugin-import`

package.json

@@ -26,18 +26,18 @@
     "check-clean-workspace-after-install": "git diff --quiet --exit-code",
     "check-configs": "nx run-many --target=check-configs --all --parallel",
     "check-docs": "nx run-many --target=check-docs --all --parallel",
-    "check-format": "prettier --list-different \"./**/*.{md,mdx,ts,js,tsx,jsx}\"",
-    "check-spelling": "cspell --config=.cspell.json \"**/*.{md,mdx,ts,js,tsx,jsx}\"",
+    "check-format": "prettier --list-different \"./**/*.{md,mdx,ts,mts,cts,js,cjs,mjs,tsx,jsx}\"",
+    "check-spelling": "cspell --config=.cspell.json \"**/*.{md,mdx,ts,mts,cts,js,cjs,mjs,tsx,jsx}\"",
     "clean": "lerna clean && lerna run clean",
     "cz": "git-cz",
-    "format": "prettier --write \"./**/*.{ts,tsx,js,jsx,json,md,css}\"",
+    "format": "prettier --write \"./**/*.{ts,mts,cts,tsx,js,mjs,cjs,jsx,json,md,css}\"",
     "generate-contributors": "yarn ts-node --transpile-only ./tools/generate-contributors.ts && yarn all-contributors generate",
     "generate-sponsors": "yarn ts-node --transpile-only ./tools/generate-sponsors.ts",
     "generate-website-dts": "yarn ts-node --transpile-only ./tools/generate-website-dts.ts",
-    "lint-fix": "eslint . --ext .js,.jsx,.ts,.tsx --fix",
+    "lint-fix": "eslint . --fix",
     "lint-markdown-fix": "yarn lint-markdown --fix",
     "lint-markdown": "markdownlint \"**/*.md\" --config=.markdownlint.json --ignore-path=.markdownlintignore",
-    "lint": "cross-env NODE_OPTIONS=\"--max-old-space-size=16384\" eslint . --ext .js,.jsx,.ts,.tsx",
+    "lint": "cross-env NODE_OPTIONS=\"--max-old-space-size=16384\" eslint .",
     "postinstall": "yarn husky install && yarn build",
     "pre-commit": "yarn lint-staged",
     "pre-push": "yarn check-format",

packages/ast-spec/package.json

@@ -33,8 +33,8 @@
     "clean": "tsc -b tsconfig.build.json --clean",
     "postclean": "rimraf dist && rimraf _ts3.4 && rimraf .rollup.cache && rimraf coverage",
     "clean-fixtures": "rimraf -g \"./src/**/fixtures/**/snapshots\"",
-    "format": "prettier --write \"./**/*.{ts,js,json,md}\" --ignore-path ../../.prettierignore",
-    "lint": "eslint . --ext .js,.ts --ignore-path='../../.eslintignore'",
+    "format": "prettier --write \"./**/*.{ts,mts,cts,tsx,js,mjs,cjs,jsx,json,md,css}\" --ignore-path ../../.prettierignore",
+    "lint": "eslint . --ignore-path='../../.eslintignore'",
     "test": "jest",
     "typecheck": "tsc -p tsconfig.json --noEmit"
   },

packages/eslint-plugin-internal/package.json

@@ -7,8 +7,8 @@
     "build": "tsc -b tsconfig.build.json",
     "clean": "tsc -b tsconfig.build.json --clean",
     "postclean": "rimraf dist && rimraf coverage",
-    "format": "prettier --write \"./**/*.{ts,js,json,md}\" --ignore-path ../../.prettierignore",
-    "lint": "eslint . --ext .js,.ts --ignore-path='../../.eslintignore'",
+    "format": "prettier --write \"./**/*.{ts,mts,cts,tsx,js,mjs,cjs,jsx,json,md,css}\" --ignore-path ../../.prettierignore",
+    "lint": "eslint . --ignore-path='../../.eslintignore'",
     "test": "jest --coverage",
     "typecheck": "tsc -p tsconfig.json --noEmit"
   },

packages/eslint-plugin-tslint/package.json

@@ -32,8 +32,8 @@
     "build": "tsc -b tsconfig.build.json",
     "clean": "tsc -b tsconfig.build.json --clean",
     "postclean": "rimraf dist && rimraf coverage",
-    "format": "prettier --write \"./**/*.{ts,js,json,md}\" --ignore-path ../../.prettierignore",
-    "lint": "eslint . --ext .js,.ts --ignore-path='../../.eslintignore'",
+    "format": "prettier --write \"./**/*.{ts,mts,cts,tsx,js,mjs,cjs,jsx,json,md,css}\" --ignore-path ../../.prettierignore",
+    "lint": "eslint . --ignore-path='../../.eslintignore'",
     "test": "jest --coverage",
     "typecheck": "tsc -p tsconfig.json --noEmit"
   },

packages/eslint-plugin/README.md

@@ -59,8 +59,6 @@ You can also enable all the recommended rules for our plugin. Add `plugin:@types
 }
 ```
 
-**Note: Make sure to use `eslint --ext .js,.ts` since by [default](https://eslint.org/docs/user-guide/command-line-interface#--ext) `eslint` will only search for `.js` files.**
-
 ### Recommended Configs
 
 You can also use [`eslint:recommended`](https://eslint.org/docs/rules/) (the set of rules which are recommended for all projects by the ESLint Team) with this plugin:

packages/eslint-plugin/docs/rules/explicit-function-return-type.md

@@ -95,7 +95,7 @@ const defaults = {
 
 ### Configuring in a mixed JS/TS codebase
 
-If you are working on a codebase within which you lint non-TypeScript code (i.e. `.js`/`.jsx`), you should ensure that you should use [ESLint `overrides`](https://eslint.org/docs/user-guide/configuring#disabling-rules-only-for-a-group-of-files) to only enable the rule on `.ts`/`.tsx` files. If you don't, then you will get unfixable lint errors reported within `.js`/`.jsx` files.
+If you are working on a codebase within which you lint non-TypeScript code (i.e. `.js`/`.mjs`/`.cjs`/`.jsx`), you should ensure that you should use [ESLint `overrides`](https://eslint.org/docs/user-guide/configuring#disabling-rules-only-for-a-group-of-files) to only enable the rule on `.ts`/`.mts`/`.cts`/`.tsx` files. If you don't, then you will get unfixable lint errors reported within `.js`/`.mjs`/`.cjs`/`.jsx` files.
 
 ```jsonc
 {
@@ -106,7 +106,7 @@ If you are working on a codebase within which you lint non-TypeScript code (i.e.
   "overrides": [
     {
       // enable the rule specifically for TypeScript files
-      "files": ["*.ts", "*.tsx"],
+      "files": ["*.ts", "*.mts", "*.cts", "*.tsx"],
       "rules": {
         "@typescript-eslint/explicit-function-return-type": ["error"]
       }

packages/eslint-plugin/docs/rules/explicit-member-accessibility.md

@@ -39,7 +39,7 @@ const defaultOptions: Options = {
 
 ### Configuring in a mixed JS/TS codebase
 
-If you are working on a codebase within which you lint non-TypeScript code (i.e. `.js`/`.jsx`), you should ensure that you should use [ESLint `overrides`](https://eslint.org/docs/user-guide/configuring#disabling-rules-only-for-a-group-of-files) to only enable the rule on `.ts`/`.tsx` files. If you don't, then you will get unfixable lint errors reported within `.js`/`.jsx` files.
+If you are working on a codebase within which you lint non-TypeScript code (i.e. `.js`/`.mjs`/`.cjs`/`.jsx`), you should ensure that you should use [ESLint `overrides`](https://eslint.org/docs/user-guide/configuring#disabling-rules-only-for-a-group-of-files) to only enable the rule on `.ts`/`.mts`/`.cts`/`.tsx` files. If you don't, then you will get unfixable lint errors reported within `.js`/`.mjs`/`.cjs`/`.jsx` files.
 
 ```jsonc
 {
@@ -50,7 +50,7 @@ If you are working on a codebase within which you lint non-TypeScript code (i.e.
   "overrides": [
     {
       // enable the rule specifically for TypeScript files
-      "files": ["*.ts", "*.tsx"],
+      "files": ["*.ts", "*.mts", "*.cts", "*.tsx"],
       "rules": {
         "@typescript-eslint/explicit-member-accessibility": ["error"]
       }

packages/eslint-plugin/docs/rules/explicit-module-boundary-types.md

@@ -110,7 +110,7 @@ const defaults = {
 
 ### Configuring in a mixed JS/TS codebase
 
-If you are working on a codebase within which you lint non-TypeScript code (i.e. `.js`/`.jsx`), you should ensure that you should use [ESLint `overrides`](https://eslint.org/docs/user-guide/configuring#disabling-rules-only-for-a-group-of-files) to only enable the rule on `.ts`/`.tsx` files. If you don't, then you will get unfixable lint errors reported within `.js`/`.jsx` files.
+If you are working on a codebase within which you lint non-TypeScript code (i.e. `.js`/`.mjs`/`.cjs`/`.jsx`), you should ensure that you should use [ESLint `overrides`](https://eslint.org/docs/user-guide/configuring#disabling-rules-only-for-a-group-of-files) to only enable the rule on `.ts`/`.mts`/`.cts`/`.tsx` files. If you don't, then you will get unfixable lint errors reported within `.js`/`.mjs`/`.cjs`/`.jsx` files.
 
 ```jsonc
 {
@@ -121,7 +121,7 @@ If you are working on a codebase within which you lint non-TypeScript code (i.e.
   "overrides": [
     {
       // enable the rule specifically for TypeScript files
-      "files": ["*.ts", "*.tsx"],
+      "files": ["*.ts", "*.mts", "*.cts", "*.tsx"],
       "rules": {
         "@typescript-eslint/explicit-module-boundary-types": ["error"]
       }

packages/eslint-plugin/package.json

@@ -36,10 +36,10 @@
     "check-configs": "jest tests/configs.test.ts --runTestsByPath --silent --runInBand",
     "clean": "tsc -b tsconfig.build.json --clean",
     "postclean": "rimraf dist && rimraf coverage",
-    "format": "prettier --write \"./**/*.{ts,js,json,md}\" --ignore-path ../../.prettierignore",
+    "format": "prettier --write \"./**/*.{ts,mts,cts,tsx,js,mjs,cjs,jsx,json,md,css}\" --ignore-path ../../.prettierignore",
     "generate:configs": "../../node_modules/.bin/ts-node --files --transpile-only tools/generate-configs.ts",
     "generate:rules-lists": "../../node_modules/.bin/ts-node --files --transpile-only tools/generate-rules-lists.ts",
-    "lint": "eslint . --ext .js,.ts --ignore-path ../../.eslintignore",
+    "lint": "eslint . --ignore-path ../../.eslintignore",
     "test": "jest --coverage",
     "typecheck": "tsc -p tsconfig.json --noEmit"
   },

packages/eslint-plugin/src/configs/eslint-recommended.ts

@@ -6,7 +6,7 @@
 export = {
   overrides: [
     {
-      files: ['*.ts', '*.tsx'],
+      files: ['*.ts', '*.tsx', '*.mts', '*.cts'],
       rules: {
         'constructor-super': 'off', // ts(2335) & ts(2377)
         'getter-return': 'off', // ts(2378)

packages/eslint-plugin/src/util/misc.ts

@@ -4,12 +4,24 @@
 
 import { AST_NODE_TYPES, TSESLint, TSESTree } from '@typescript-eslint/utils';
 import { requiresQuoting } from '@typescript-eslint/type-utils';
+import * as ts from 'typescript';
 
+const DEFINITION_EXTENSIONS = [
+  ts.Extension.Dts,
+  ts.Extension.Dcts,
+  ts.Extension.Dmts,
+] as const;
 /**
  * Check if the context file name is *.d.ts or *.d.tsx
  */
 function isDefinitionFile(fileName: string): boolean {
-  return /\.d\.tsx?$/i.test(fileName || '');
+  const lowerFileName = fileName.toLowerCase();
+  for (const definitionExt of DEFINITION_EXTENSIONS) {
+    if (lowerFileName.endsWith(definitionExt)) {
+      return true;
+    }
+  }
+  return false;
 }
 
 /**

packages/eslint-plugin/tests/util.test.ts

@@ -1,7 +1,7 @@
 import * as util from '../src/util';
 
 describe('isDefinitionFile', () => {
-  it('returns false for non-definition files', () => {
+  describe('returns false for non-definition files', () => {
     const invalid = [
       'test.js',
       'test.jsx',
@@ -15,18 +15,25 @@ describe('isDefinitionFile', () => {
       'test.tsx',
       'test.TS',
       'test.TSX',
+      // yes, it's not a definition file if it's a `.d.tsx`!
+      'test.d.tsx',
+      'test.D.TSX',
     ];
 
     invalid.forEach(f => {
-      expect(util.isDefinitionFile(f)).toBe(false);
+      it(f, () => {
+        expect(util.isDefinitionFile(f)).toBe(false);
+      });
     });
   });
 
-  it('returns true for definition files', () => {
-    const valid = ['test.d.ts', 'test.d.tsx', 'test.D.TS', 'test.D.TSX'];
+  describe('returns true for definition files', () => {
+    const valid = ['test.d.ts', 'test.D.TS'];
 
     valid.forEach(f => {
-      expect(util.isDefinitionFile(f)).toBe(true);
+      it(f, () => {
+        expect(util.isDefinitionFile(f)).toBe(true);
+      });
     });
   });
 });

packages/experimental-utils/package.json

@@ -33,8 +33,8 @@
     "postbuild": "downlevel-dts dist _ts3.4/dist",
     "clean": "tsc -b tsconfig.build.json --clean",
     "postclean": "rimraf dist && rimraf _ts3.4 && rimraf coverage",
-    "format": "prettier --write \"./**/*.{ts,js,json,md}\" --ignore-path ../../.prettierignore",
-    "lint": "eslint . --ext .js,.ts --ignore-path='../../.eslintignore'",
+    "format": "prettier --write \"./**/*.{ts,mts,cts,tsx,js,mjs,cjs,jsx,json,md,css}\" --ignore-path ../../.prettierignore",
+    "lint": "eslint . --ignore-path='../../.eslintignore'",
     "typecheck": "tsc -p tsconfig.json --noEmit"
   },
   "dependencies": {

packages/parser/README.md

@@ -78,16 +78,19 @@ Default `false`.
 
 Enable parsing JSX when `true`. More details can be found [here](https://www.typescriptlang.org/docs/handbook/jsx.html).
 
-**NOTE:** this setting does not affect known file types (`.js`, `.jsx`, `.ts`, `.tsx`, `.json`) because the TypeScript compiler has its own internal handling for known file extensions. The exact behavior is as follows:
+**NOTE:** this setting does not affect known file types (`.js`, `.mjs`, `.cjs`, `.jsx`, `.ts`, `.mts`, `.cts`, `.tsx`, `.json`) because the TypeScript compiler has its own internal handling for known file extensions.
 
-- if `parserOptions.project` is _not_ provided:
-  - `.js`, `.jsx`, `.tsx` files are parsed as if this is true.
-  - `.ts` files are parsed as if this is false.
-  - unknown extensions (`.md`, `.vue`) will respect this setting.
-- if `parserOptions.project` is provided (i.e. you are using rules with type information):
-  - `.js`, `.jsx`, `.tsx` files are parsed as if this is true.
-  - `.ts` files are parsed as if this is false.
-  - "unknown" extensions (`.md`, `.vue`) **are parsed as if this is false**.
+<!-- https://github.com/microsoft/TypeScript/blob/d6e483b8dabd8fd37c00954c3f2184bb7f1eb90c/src/compiler/utilities.ts#L6281-L6285 -->
+
+The exact behavior is as follows:
+
+- `.js`, `.mjs`, `.cjs`, `.jsx`, `.tsx` files are always parsed as if this is `true`.
+- `.ts`, `.mts`, `.cts` files are always parsed as if this is `false`.
+- For "unknown" extensions (`.md`, `.vue`):
+  - If `parserOptions.project` is _not_ provided:
+    - The setting will be respected.
+  - If `parserOptions.project` is provided (i.e. you are using rules with type information):
+    - **always parsed as if this is `false`**
 
 ### `parserOptions.ecmaFeatures.globalReturn`
 
@@ -203,7 +206,8 @@ For example, by default it will ensure that a glob like `./**/tsconfig.json` wil
 Default `undefined`.
 
 This option allows you to provide one or more additional file extensions which should be considered in the TypeScript Program compilation.
-The default extensions are `.ts`, `.tsx`, `.js`, and `.jsx`. Add extensions starting with `.`, followed by the file extension. E.g. for a `.vue` file use `"extraFileExtensions": [".vue"]`.
+The default extensions are `['.js', '.mjs', '.cjs', '.jsx', '.ts', '.mts', '.cts', '.tsx']`.
+Add extensions starting with `.`, followed by the file extension. E.g. for a `.vue` file use `"extraFileExtensions": [".vue"]`.
 
 ### `parserOptions.warnOnUnsupportedTypeScriptVersion`
 

packages/parser/package.json

@@ -35,8 +35,8 @@
     "postbuild": "downlevel-dts dist _ts3.4/dist",
     "clean": "tsc -b tsconfig.build.json --clean",
     "postclean": "rimraf dist && rimraf _ts3.4 && rimraf coverage",
-    "format": "prettier --write \"./**/*.{ts,js,json,md}\" --ignore-path ../../.prettierignore",
-    "lint": "eslint . --ext .js,.ts --ignore-path='../../.eslintignore'",
+    "format": "prettier --write \"./**/*.{ts,mts,cts,tsx,js,mjs,cjs,jsx,json,md,css}\" --ignore-path ../../.prettierignore",
+    "lint": "eslint . --ignore-path='../../.eslintignore'",
     "test": "jest --coverage",
     "typecheck": "tsc -p tsconfig.json --noEmit"
   },

packages/parser/src/parser.ts

@@ -36,7 +36,7 @@ function validateBoolean(
   return value;
 }
 
-const LIB_FILENAME_REGEX = /lib\.(.+)\.d\.ts$/;
+const LIB_FILENAME_REGEX = /lib\.(.+)\.d\.[cm]?ts$/;
 function getLib(compilerOptions: CompilerOptions): Lib[] {
   if (compilerOptions.lib) {
     return compilerOptions.lib.reduce((acc, lib) => {
@@ -110,13 +110,6 @@ function parseForESLint(
     sourceType: options.sourceType,
   };
 
-  if (typeof options.filePath === 'string') {
-    const tsx = options.filePath.endsWith('.tsx');
-    if (tsx || options.filePath.endsWith('.ts')) {
-      parserOptions.jsx = tsx;
-    }
-  }
-
   /**
    * Allow the user to suppress the warning from typescript-estree if they are using an unsupported
    * version of TypeScript

packages/scope-manager/package.json

@@ -31,7 +31,7 @@
     "build": "cd ../../ && nx build @typescript-eslint/scope-manager",
     "clean": "cd ../../ && nx clean @typescript-eslint/scope-manager",
     "clean-fixtures": "cd ../../ && nx clean-fixtures @typescript-eslint/scope-manager",
-    "format": "prettier --write \"./**/*.{ts,js,json,md}\" --ignore-path ../../.prettierignore",
+    "format": "prettier --write \"./**/*.{ts,mts,cts,tsx,js,mjs,cjs,jsx,json,md,css}\" --ignore-path ../../.prettierignore",
     "generate:lib": "cd ../../ && nx generate-lib @typescript-eslint/scope-manager",
     "lint": "cd ../../ && nx lint @typescript-eslint/scope-manager",
     "test": "cd ../../ && nx test @typescript-eslint/scope-manager --code-coverage",