feat: support ESLint v9

package.json

@@ -62,7 +62,7 @@
     "@babel/eslint-parser": "^7.24.1",
     "@babel/parser": "^7.24.4",
     "@babel/types": "^7.24.0",
-    "@eslint/eslintrc": "^2.1.4",
+    "@eslint/eslintrc": "^3.0.2",
     "@eslint/js": "^8.57.0",
     "@nx/eslint": "18.2.3",
     "@nx/jest": "18.2.3",
@@ -87,7 +87,7 @@
     "cross-fetch": "^4.0.0",
     "cspell": "^8.6.1",
     "downlevel-dts": ">=0.11.0",
-    "eslint": "8.57.0",
+    "eslint": "9.1.1",
     "eslint-plugin-deprecation": "^2.0.0",
     "eslint-plugin-eslint-comments": "^3.2.0",
     "eslint-plugin-eslint-plugin": "^5.5.0",
@@ -124,6 +124,8 @@
     "yargs": "17.7.2"
   },
   "resolutions": {
+    "@eslint/eslintrc": "^3.0.2",
+    "@eslint/js": "9.1.1",
     "@jest/create-cache-key-function": "^29",
     "@jest/reporters": "^29",
     "@jest/test-result": "^29",
@@ -133,7 +135,7 @@
     "@types/estree": "link:./tools/dummypkg",
     "@types/node": "^20.0.0",
     "@types/react": "^18.2.14",
-    "eslint": "8.57.0",
+    "eslint": "9.1.1",
     "eslint-visitor-keys": "^3.4.1",
     "jest-config": "^29",
     "jest-resolve": "^29",

packages/eslint-plugin/package.json

@@ -103,7 +103,7 @@
   },
   "peerDependencies": {
     "@typescript-eslint/parser": "^7.0.0",
-    "eslint": "^8.57.0"
+    "eslint": "^9.0.0"
   },
   "peerDependenciesMeta": {
     "typescript": {

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

@@ -100,7 +100,7 @@ function renderLintResults(code: string, errors: Linter.LintMessage[]): string {
   return output.join('\n').trim() + '\n';
 }
 
-const linter = new Linter();
+const linter = new Linter({ configType: 'eslintrc' });
 linter.defineParser('@typescript-eslint/parser', tseslintParser);
 
 const eslintOutputSnapshotFolder = path.resolve(

packages/eslint-plugin/tests/rules/array-type.test.ts

@@ -1924,7 +1924,7 @@ interface FooInterface {
 // -- eslint rule tester is not working with multi-pass
 // https://github.com/eslint/eslint/issues/11187
 describe('array-type (nested)', () => {
-  const linter = new TSESLint.Linter();
+  const linter = new TSESLint.Linter({ configType: 'eslintrc' });
   linter.defineRule('array-type', rule);
   linter.defineParser('@typescript-eslint/parser', parser);
 

packages/eslint-plugin/tests/rules/no-unused-vars/no-unused-vars-eslint.test.ts

@@ -17,17 +17,25 @@ const ruleTester = new RuleTester({
   },
 });
 
-ruleTester.defineRule('use-every-a', context => {
-  /**
-   * Mark a variable as used
-   */
-  function useA(node: TSESTree.Node): void {
-    context.sourceCode.markVariableAsUsed('a', node);
-  }
-  return {
-    VariableDeclaration: useA,
-    ReturnStatement: useA,
-  };
+ruleTester.defineRule('use-every-a', {
+  create: context => {
+    /**
+     * Mark a variable as used
+     */
+    function useA(node: TSESTree.Node): void {
+      context.sourceCode.markVariableAsUsed('a', node);
+    }
+    return {
+      VariableDeclaration: useA,
+      ReturnStatement: useA,
+    };
+  },
+  defaultOptions: [],
+  meta: {
+    messages: {},
+    type: 'problem',
+    schema: [],
+  },
 });
 
 /**

packages/integration-tests/fixtures/eslint-v8/package.json

@@ -1,5 +1,5 @@
 {
   "devDependencies": {
-    "eslint": "8.57.0"
+    "eslint": "9.0.0"
   }
 }

packages/parser/package.json

@@ -49,7 +49,7 @@
     "typecheck": "tsc -p tsconfig.json --noEmit"
   },
   "peerDependencies": {
-    "eslint": "^8.57.0"
+    "eslint": "^9.0.0"
   },
   "dependencies": {
     "@typescript-eslint/scope-manager": "7.7.1",

packages/rule-tester/package.json

@@ -56,7 +56,7 @@
   },
   "peerDependencies": {
     "@eslint/eslintrc": ">=2",
-    "eslint": "^8.57.0"
+    "eslint": "^9.0.0"
   },
   "devDependencies": {
     "@types/lodash.merge": "4.6.9",

packages/rule-tester/src/RuleTester.ts

@@ -76,7 +76,7 @@ let defaultConfig = deepMerge(
 export class RuleTester extends TestFramework {
   readonly #testerConfig: TesterConfigWithDefaults;
   readonly #rules: Record<string, AnyRuleCreateFunction | AnyRuleModule> = {};
-  readonly #linter: Linter = new Linter();
+  readonly #linter: Linter = new Linter({ configType: 'eslintrc' });
 
   /**
    * Creates a new instance of RuleTester.

packages/type-utils/package.json

@@ -61,7 +61,7 @@
     "typescript": "*"
   },
   "peerDependencies": {
-    "eslint": "^8.57.0"
+    "eslint": "^9.0.0"
   },
   "peerDependenciesMeta": {
     "typescript": {

packages/typescript-eslint/package.json

@@ -52,7 +52,7 @@
     "typecheck": "tsc -p tsconfig.json --noEmit"
   },
   "peerDependencies": {
-    "eslint": "^8.57.0"
+    "eslint": "^9.0.0"
   },
   "dependencies": {
     "@typescript-eslint/eslint-plugin": "7.7.1",

packages/utils/package.json

@@ -76,7 +76,7 @@
     "semver": "^7.6.0"
   },
   "peerDependencies": {
-    "eslint": "^8.57.0"
+    "eslint": "^9.0.0"
   },
   "devDependencies": {
     "@typescript-eslint/parser": "7.7.1",

packages/website-eslint/src/index.js

@@ -24,7 +24,7 @@ exports.astConverter = astConverter;
 exports.esquery = esquery;
 
 exports.createLinter = function () {
-  const linter = new Linter();
+  const linter = new Linter({ configType: 'eslintrc' });
   for (const name in plugin.rules) {
     linter.defineRule(`@typescript-eslint/${name}`, plugin.rules[name]);
   }

packages/website-eslint/types/eslint.d.ts

@@ -9,7 +9,11 @@ it just uses `any` for the import - marking it as an untyped export. So adding t
 cannot use VSCode's cache ever - stubbing it out permanently.
 */
 declare module 'eslint' {
+  export interface LinterOptions {
+    configType?: 'eslintrc';
+  }
   export class Linter {
+    constructor(options: LinterOptions);
     defineRule(name: string, rule: unknown): void;
   }
 }