chore: use eslint 9 internally (typescript-eslint#9119)

* eslint 9

* add compat

* add fixup

* fixup react

* add more fixups

* add issue comment

* lint and empty types

* fix types

* remove eslint9 ci test

* rename

* update no-restricted-imports snapshot

* update build script

* change quote style

* revert renaming

* begin migrating config files

* migrate markdown to v9

* migrate recommended-does-not-require-program

* migrate eslint.config.js

* migrate vue-sfc, except for TS errors

* remove flatconfig boolean

* remove config file option

* remove deprecated rules

* correct issue

* revert style change

* add clarifying comment

* remove unnecessary suppression

* remove unnecessary suppression

* remove unused suppression

.github/workflows/ci.yml

@@ -134,25 +134,6 @@ jobs:
         run: yarn stylelint
         working-directory: packages/website
 
-  eslint_v9_tests:
-    name: Run tests on ESLint v9
-    needs: [build]
-    runs-on: ubuntu-latest
-    steps:
-      - name: Checkout
-        uses: actions/checkout@v4
-      - name: Install
-        uses: ./.github/actions/prepare-install
-        with:
-          node-version: ${{ env.PRIMARY_NODE_VERSION }}
-      - name: Build
-        uses: ./.github/actions/prepare-build
-      - run: yarn add eslint@9
-      - name: Run tests
-        run: yarn test
-        env:
-          CI: true
-
   integration_tests:
     name: Run integration tests on primary Node.js version
     needs: [build]

eslint.config.mjs

@@ -2,6 +2,7 @@
 
 import url from 'node:url';
 
+import { fixupConfigRules, fixupPluginRules } from '@eslint/compat';
 import { FlatCompat } from '@eslint/eslintrc';
 import eslint from '@eslint/js';
 import tseslintInternalPlugin from '@typescript-eslint/eslint-plugin-internal';
@@ -29,15 +30,20 @@ export default tseslint.config(
     plugins: {
       ['@typescript-eslint']: tseslint.plugin,
       ['@typescript-eslint/internal']: tseslintInternalPlugin,
-      ['deprecation']: deprecationPlugin,
+      // https://github.com/gund/eslint-plugin-deprecation/issues/78
+      // https://github.com/typescript-eslint/typescript-eslint/issues/8988
+      ['deprecation']: fixupPluginRules(deprecationPlugin),
       ['eslint-comments']: eslintCommentsPlugin,
       ['eslint-plugin']: eslintPluginPlugin,
-      ['import']: importPlugin,
+      // https://github.com/import-js/eslint-plugin-import/issues/2948
+      ['import']: fixupPluginRules(importPlugin),
       ['jest']: jestPlugin,
       ['jsdoc']: jsdocPlugin,
       ['jsx-a11y']: jsxA11yPlugin,
-      ['react-hooks']: reactHooksPlugin,
-      ['react']: reactPlugin,
+      // https://github.com/facebook/react/issues/28313
+      ['react-hooks']: fixupPluginRules(reactHooksPlugin),
+      // https://github.com/jsx-eslint/eslint-plugin-react/issues/3699
+      ['react']: fixupPluginRules(reactPlugin),
       ['simple-import-sort']: simpleImportSortPlugin,
       ['unicorn']: unicornPlugin,
     },
@@ -512,8 +518,8 @@ export default tseslint.config(
     files: ['packages/website/**/*.{ts,tsx,mts,cts,js,jsx}'],
     extends: [
       ...compat.config(jsxA11yPlugin.configs.recommended),
-      ...compat.config(reactPlugin.configs.recommended),
-      ...compat.config(reactHooksPlugin.configs.recommended),
+      ...fixupConfigRules(compat.config(reactPlugin.configs.recommended)),
+      ...fixupConfigRules(compat.config(reactHooksPlugin.configs.recommended)),
     ],
     rules: {
       '@typescript-eslint/internal/prefer-ast-types-enum': 'off',

package.json

@@ -60,6 +60,7 @@
     "@babel/eslint-parser": "^7.24.1",
     "@babel/parser": "^7.24.4",
     "@babel/types": "^7.24.0",
+    "@eslint/compat": "^1.0.1",
     "@eslint/eslintrc": "^2.1.4",
     "@eslint/js": "^8.57.0",
     "@jest/types": "29.6.3",
@@ -85,7 +86,7 @@
     "cross-fetch": "^4.0.0",
     "cspell": "^8.6.1",
     "downlevel-dts": ">=0.11.0",
-    "eslint": "8.57.0",
+    "eslint": "^9.3.0",
     "eslint-plugin-deprecation": "^2.0.0",
     "eslint-plugin-eslint-comments": "^3.2.0",
     "eslint-plugin-eslint-plugin": "^5.5.0",
@@ -129,7 +130,7 @@
     "@types/estree": "link:./tools/dummypkg",
     "@types/node": "^20.0.0",
     "@types/react": "^18.2.14",
-    "eslint": "8.57.0",
+    "eslint": "^9",
     "eslint-visitor-keys": "^3.4.1",
     "jest-config": "^29",
     "jest-resolve": "^29",

packages/eslint-plugin/rules.d.ts

@@ -74,5 +74,4 @@ export type TypeScriptESLintRules = Record<
 >;
 
 declare const rules: TypeScriptESLintRules;
-// eslint-disable-next-line import/no-default-export
 export default rules;

packages/eslint-plugin/src/rules/prefer-regexp-exec.ts

@@ -1,4 +1,3 @@
-/* eslint-disable @typescript-eslint/prefer-literal-enum-member */
 import type { TSESTree } from '@typescript-eslint/utils';
 import { AST_NODE_TYPES } from '@typescript-eslint/utils';
 import * as tsutils from 'ts-api-utils';

packages/eslint-plugin/tests/rules/prefer-optional-chain/base-cases.ts

@@ -229,10 +229,6 @@ const RawBaseCases = (operator: '&&' | '||') =>
   ] as const;
 
 export const identity: MutateFn = c => c;
-/*
-eslint-disable-next-line eslint-plugin/prefer-message-ids, eslint-plugin/prefer-object-rule, eslint-plugin/require-meta-type, eslint-plugin/require-meta-schema --
-TODO - bug in hte rules - https://github.com/eslint-community/eslint-plugin-eslint-plugin/issues/455
-*/
 export const BaseCases: BaseCaseCreator = ({
   operator,
   mutateCode = identity,

packages/integration-tests/fixtures/markdown/eslint.config.js

@@ -0,0 +1,15 @@
+import markdown from 'eslint-plugin-markdown';
+import tseslint from 'typescript-eslint';
+
+export default tseslint.config(
+  tseslint.configs.base,
+  // this will also ensure that eslint will force lint the markdown files
+  { plugins: { markdown }, files: ['**/*.md'], processor: 'markdown/markdown' },
+  {
+    files: ['**/*.md/*.{js,ts,jsx,tsx,javascript,node}'],
+    rules: {
+      '@typescript-eslint/no-explicit-any': 'error',
+      'no-console': 'error',
+    },
+  },
+);

packages/integration-tests/fixtures/markdown/package.json

@@ -1,4 +1,5 @@
 {
+  "type": "module",
   "devDependencies": {
     "eslint-plugin-markdown": "latest"
   }

packages/integration-tests/fixtures/recommended-does-not-require-program/.eslintrc.js → packages/integration-tests/fixtures/recommended-does-not-require-program/eslint.config.js

@@ -1,14 +1,11 @@
+import eslint from '@eslint/js';
+import tseslint from 'typescript-eslint';
+
 // This integration test exists to make sure that the recommended config does
 // not require a program to be specified to ensure a fast and simple initial
 // setup. Users can add on one of our other configs if they want to opt in to
 // more expensive checks.
-module.exports = {
-  root: true,
-  parser: '@typescript-eslint/parser',
-  extends: [
-    'eslint:recommended',
-    'plugin:@typescript-eslint/eslint-recommended',
-    'plugin:@typescript-eslint/recommended',
-  ],
-  plugins: ['@typescript-eslint'],
-};
+export default tseslint.config(
+  eslint.configs.recommended,
+  ...tseslint.configs.recommended,
+);

packages/integration-tests/fixtures/recommended-does-not-require-program/package.json

@@ -1,3 +1,4 @@
 {
+  "type": "module",
   "devDependencies": {}
 }

packages/integration-tests/fixtures/vue-jsx/eslint.config.js

@@ -0,0 +1,13 @@
+import tseslint from 'typescript-eslint';
+import pluginVue from 'eslint-plugin-vue';
+
+export default tseslint.config(
+  tseslint.configs.base,
+  ...pluginVue.configs['flat/essential'],
+  {
+    languageOptions: {
+      parserOptions: { ecmaFeatures: { jsx: true }, parser: tseslint.parser },
+    },
+    rules: { '@typescript-eslint/no-explicit-any': 'error' },
+  },
+);

packages/integration-tests/fixtures/vue-jsx/package.json

@@ -1,4 +1,5 @@
 {
+  "type": "module",
   "devDependencies": {
     "vue-eslint-parser": "latest",
     "eslint-plugin-vue": "latest",

packages/integration-tests/fixtures/vue-sfc/eslint.config.js

@@ -0,0 +1,20 @@
+import pluginVue from 'eslint-plugin-vue';
+import tseslint from 'typescript-eslint';
+
+export default tseslint.config(
+  tseslint.configs.base,
+  ...pluginVue.configs['flat/essential'],
+  {
+    languageOptions: {
+      parserOptions: {
+        parser: tseslint.parser,
+        project: '/usr/linked/tsconfig.json',
+      },
+    },
+    rules: {
+      '@typescript-eslint/no-explicit-any': 'error',
+      '@typescript-eslint/no-unnecessary-type-assertion': 'error',
+      'semi-spacing': 'error',
+    },
+  },
+);

packages/integration-tests/fixtures/vue-sfc/package.json

@@ -1,4 +1,5 @@
 {
+  "type": "module",
   "devDependencies": {
     "vue-eslint-parser": "latest",
     "eslint-plugin-vue": "latest",

packages/integration-tests/tests/__snapshots__/recommended-does-not-require-program.test.ts.snap

@@ -24,16 +24,7 @@ exports[`recommended-does-not-require-program eslint should work successfully 1`
     "output": "const foo: unknown = true;
 ",
     "suppressedMessages": [],
-    "usedDeprecatedRules": [
-      {
-        "replacedBy": [],
-        "ruleId": "no-extra-semi",
-      },
-      {
-        "replacedBy": [],
-        "ruleId": "no-mixed-spaces-and-tabs",
-      },
-    ],
+    "usedDeprecatedRules": [],
     "warningCount": 0,
   },
 ]

packages/integration-tests/tests/flat-config-types.test.ts

@@ -25,4 +25,4 @@ for (const additionalFlags of [
     },
   );
 }
-eslintIntegrationTest(__filename, 'eslint.config.js', true);
+eslintIntegrationTest(__filename, 'eslint.config.js');

packages/integration-tests/tools/integration-test-base.ts

@@ -128,7 +128,6 @@ function integrationTest(
 export function eslintIntegrationTest(
   testFilename: string,
   filesGlob: string,
-  flatConfig = false,
 ): void {
   integrationTest('eslint', testFilename, async testFolder => {
     // lint, outputting to a JSON file
@@ -143,8 +142,6 @@ export function eslintIntegrationTest(
           'json',
           '--output-file',
           outFile,
-          '--config',
-          flatConfig ? './eslint.config.js' : './.eslintrc.js',
           '--fix-dry-run',
           filesGlob,
         ],