fix(linter): support eslint v10

packages/eslint/package.json

@@ -32,7 +32,7 @@
   "executors": "./executors.json",
   "peerDependencies": {
     "@zkochan/js-yaml": "0.0.7",
-    "eslint": "^8.0.0 || ^9.0.0"
+    "eslint": "^8.0.0 || ^9.0.0 || ^10.0.0"
   },
   "dependencies": {
     "@nx/devkit": "workspace:*",

packages/eslint/src/executors/lint/utility/eslint-utils.spec.ts

@@ -1,3 +1,7 @@
+jest.mock('eslint', () => ({
+  loadESLint: undefined,
+}));
+
 jest.mock('eslint/use-at-your-own-risk', () => ({
   LegacyESLint: jest.fn(),
 }));
@@ -7,6 +11,9 @@ import { resolveAndInstantiateESLint } from './eslint-utils';
 
 describe('eslint-utils', () => {
   beforeEach(() => {
+    const eslintModule = require('eslint');
+    eslintModule.loadESLint = undefined;
+
     jest.clearAllMocks();
   });
 
@@ -54,6 +61,33 @@ describe('eslint-utils', () => {
     });
   });
 
+  it('should create the ESLint instance with loadESLint when available', async () => {
+    const eslintModule = require('eslint');
+    const LoadedESLintClass = jest.fn();
+    eslintModule.loadESLint = jest.fn().mockResolvedValue(LoadedESLintClass);
+
+    await resolveAndInstantiateESLint('./.eslintrc.json', {} as any);
+
+    expect(eslintModule.loadESLint).toHaveBeenCalledWith({
+      useFlatConfig: false,
+    });
+    expect(LoadedESLintClass).toHaveBeenCalledWith({
+      overrideConfigFile: './.eslintrc.json',
+      fix: false,
+      cache: false,
+      cacheLocation: undefined,
+      cacheStrategy: undefined,
+      errorOnUnmatchedPattern: false,
+
+      ignorePath: undefined,
+      reportUnusedDisableDirectives: undefined,
+      resolvePluginsRelatedTo: undefined,
+      rulePaths: [],
+      useEslintrc: true,
+    });
+    expect(LegacyESLint).not.toHaveBeenCalled();
+  });
+
   describe('noEslintrc', () => {
     it('should create the ESLint instance with "useEslintrc" set to false', async () => {
       await resolveAndInstantiateESLint(undefined, <any>{
@@ -207,5 +241,35 @@ describe('eslint-utils', () => {
         `"For Flat Config, ESLint removed \`ignorePath\` and so it is not supported as an option. See https://eslint.org/docs/latest/use/configure/configuration-files-new"`
       );
     });
+
+    it('should resolve flat ESLint v9+ using loadESLint when available', async () => {
+      const eslintModule = require('eslint');
+      const LoadedESLintClass: jest.Mock & { version?: string } = jest.fn();
+      LoadedESLintClass.version = '9.0.0';
+      eslintModule.loadESLint = jest.fn().mockResolvedValue(LoadedESLintClass);
+
+      await resolveAndInstantiateESLint(
+        'eslint.config.mjs',
+        {
+          quiet: true,
+        } as any,
+        true
+      );
+
+      expect(eslintModule.loadESLint).toHaveBeenCalledWith({
+        useFlatConfig: true,
+      });
+      expect(LoadedESLintClass).toHaveBeenCalledWith({
+        overrideConfigFile: 'eslint.config.mjs',
+        fix: false,
+        cache: false,
+        cacheLocation: undefined,
+        cacheStrategy: undefined,
+        errorOnUnmatchedPattern: false,
+
+        ruleFilter: expect.any(Function),
+      });
+      expect(LegacyESLint).not.toHaveBeenCalled();
+    });
   });
 });

packages/eslint/src/executors/lint/utility/eslint-utils.ts

@@ -11,7 +11,6 @@ export async function resolveAndInstantiateESLint(
 ) {
   if (useFlatConfig && eslintConfigPath && !isFlatConfig(eslintConfigPath)) {
     throw new Error(
-      // todo: add support for eslint.config.mjs,
       'When using the new Flat Config with ESLint, all configs must be named eslint.config.js or eslint.config.cjs and .eslintrc files may not be used. See https://eslint.org/docs/latest/use/configure/configuration-files'
     );
   }

packages/eslint/src/utils/resolve-eslint-class.ts

@@ -5,18 +5,29 @@ export async function resolveESLintClass(opts?: {
   useFlatConfigOverrideVal: boolean;
 }): Promise<typeof ESLint> {
   try {
+    const shouldESLintUseFlatConfig =
+      typeof opts?.useFlatConfigOverrideVal === 'boolean'
+        ? opts.useFlatConfigOverrideVal
+        : useFlatConfig();
+
+    // In eslint 8.57.0 (the final v8 version), a dedicated API was added for resolving the correct ESLint class.
+    const eslintModule = (await import('eslint')) as typeof import('eslint') & {
+      loadESLint?: (opts: { useFlatConfig: boolean }) => Promise<typeof ESLint>;
+    };
+
+    if (typeof eslintModule.loadESLint === 'function') {
+      return await eslintModule.loadESLint({
+        useFlatConfig: shouldESLintUseFlatConfig,
+      });
+    }
+
     // Explicitly use the FlatESLint and LegacyESLint classes here because the ESLint class points at a different one based on ESLint v8 vs ESLint v9
     // But the decision on which one to use is not just based on the major version of ESLint.
     // @ts-expect-error The may be wrong based on our installed eslint version
     const { LegacyESLint, FlatESLint } = await import(
       'eslint/use-at-your-own-risk'
     );
 
-    const shouldESLintUseFlatConfig =
-      typeof opts?.useFlatConfigOverrideVal === 'boolean'
-        ? opts.useFlatConfigOverrideVal
-        : useFlatConfig();
-
     return shouldESLintUseFlatConfig ? FlatESLint : LegacyESLint;
   } catch {
     throw new Error(