fix(linter): update eslint config lookup to correctly handle configs …

…at the root (#26508)

packages/eslint/src/executors/lint/lint.impl.spec.ts

@@ -443,6 +443,36 @@ Occurred while linting ${mockContext.root}/apps/proj/src/some-file.ts`
 Error: You have attempted to use the lint rule "@typescript-eslint/await-thenable" which requires the full TypeScript type-checker to be available, but you do not have "parserOptions.project" configured to point at your project tsconfig.json files in the relevant TypeScript file "overrides" block of your ESLint config "apps/proj/eslint.config.js"
 Occurred while linting ${mockContext.root}/apps/proj/src/some-file.ts
 
+Please see https://nx.dev/recipes/tips-n-tricks/eslint for full guidance on how to resolve this issue.
+`
+      );
+    });
+
+    it('should intercept the error from `@typescript-eslint` regarding missing parserServices and provide a more detailed user-facing message logging the found flat config at the workspace root', async () => {
+      setupMocks();
+      tempFs.createFileSync('eslint.config.js', '');
+      tempFs.createFileSync('apps/proj/src/some-file.ts', '');
+
+      mockLintFiles.mockImplementation(() => {
+        throw new Error(
+          `Error while loading rule '@typescript-eslint/await-thenable': You have used a rule which requires parserServices to be generated. You must therefore provide a value for the "parserOptions.project" property for @typescript-eslint/parser.
+Occurred while linting ${mockContext.root}/apps/proj/src/some-file.ts`
+        );
+      });
+
+      await lintExecutor(
+        createValidRunBuilderOptions({
+          lintFilePatterns: ['includedFile1'],
+          format: 'json',
+          silent: false,
+        }),
+        mockContext
+      );
+      expect(console.error).toHaveBeenCalledWith(
+        `
+Error: You have attempted to use the lint rule "@typescript-eslint/await-thenable" which requires the full TypeScript type-checker to be available, but you do not have "parserOptions.project" configured to point at your project tsconfig.json files in the relevant TypeScript file "overrides" block of your ESLint config "eslint.config.js"
+Occurred while linting ${mockContext.root}/apps/proj/src/some-file.ts
+
 Please see https://nx.dev/recipes/tips-n-tricks/eslint for full guidance on how to resolve this issue.
 `
       );
@@ -473,6 +503,36 @@ Occurred while linting ${mockContext.root}/apps/proj/src/some-file.ts`
 Error: You have attempted to use the lint rule "@typescript-eslint/await-thenable" which requires the full TypeScript type-checker to be available, but you do not have "parserOptions.project" configured to point at your project tsconfig.json files in the relevant TypeScript file "overrides" block of your ESLint config "apps/proj/.eslintrc.json"
 Occurred while linting ${mockContext.root}/apps/proj/src/some-file.ts
 
+Please see https://nx.dev/recipes/tips-n-tricks/eslint for full guidance on how to resolve this issue.
+`
+      );
+    });
+
+    it('should intercept the error from `@typescript-eslint` regarding missing parserServices and provide a more detailed user-facing message logging the found old config at the workspace root', async () => {
+      setupMocks();
+      tempFs.createFileSync('.eslintrc.json', '{}');
+      tempFs.createFileSync('apps/proj/src/some-file.ts', '');
+
+      mockLintFiles.mockImplementation(() => {
+        throw new Error(
+          `Error while loading rule '@typescript-eslint/await-thenable': You have used a rule which requires parserServices to be generated. You must therefore provide a value for the "parserOptions.project" property for @typescript-eslint/parser.
+Occurred while linting ${mockContext.root}/apps/proj/src/some-file.ts`
+        );
+      });
+
+      await lintExecutor(
+        createValidRunBuilderOptions({
+          lintFilePatterns: ['includedFile1'],
+          format: 'json',
+          silent: false,
+        }),
+        mockContext
+      );
+      expect(console.error).toHaveBeenCalledWith(
+        `
+Error: You have attempted to use the lint rule "@typescript-eslint/await-thenable" which requires the full TypeScript type-checker to be available, but you do not have "parserOptions.project" configured to point at your project tsconfig.json files in the relevant TypeScript file "overrides" block of your ESLint config ".eslintrc.json"
+Occurred while linting ${mockContext.root}/apps/proj/src/some-file.ts
+
 Please see https://nx.dev/recipes/tips-n-tricks/eslint for full guidance on how to resolve this issue.
 `
       );

packages/eslint/src/utils/config-file.spec.ts

@@ -0,0 +1,106 @@
+import { TempFs } from '@nx/devkit/internal-testing-utils';
+import { join } from 'path';
+import {
+  ESLINT_FLAT_CONFIG_FILENAMES,
+  ESLINT_OLD_CONFIG_FILENAMES,
+  findFlatConfigFile,
+  findOldConfigFile,
+} from './config-file';
+
+describe('config-file', () => {
+  let fs: TempFs;
+
+  beforeEach(() => {
+    fs = new TempFs('eslint-config-file');
+  });
+
+  afterEach(() => {
+    fs.cleanup();
+  });
+
+  describe('findFlatConfigFile', () => {
+    it.each(ESLINT_FLAT_CONFIG_FILENAMES)(
+      'should find flat config file "%s" when it exists in the directory',
+      (configFile) => {
+        fs.createFilesSync({
+          [`libs/lib1/${configFile}`]: '',
+        });
+
+        const result = findFlatConfigFile('libs/lib1', fs.tempDir);
+
+        expect(result).toEqual(join(fs.tempDir, `libs/lib1/${configFile}`));
+      }
+    );
+
+    it.each(ESLINT_FLAT_CONFIG_FILENAMES)(
+      'should find flat config file "%s" when it exists in a parent directory',
+      (configFile) => {
+        fs.createFilesSync({
+          [`libs/${configFile}`]: '',
+          'libs/lib1/src/index.ts': '',
+        });
+
+        const result = findFlatConfigFile('libs/lib1', fs.tempDir);
+
+        expect(result).toEqual(join(fs.tempDir, `libs/${configFile}`));
+      }
+    );
+
+    it.each(ESLINT_FLAT_CONFIG_FILENAMES)(
+      'should find flat config file "%s" when it exists at the workspace root',
+      (configFile) => {
+        fs.createFilesSync({
+          [configFile]: '',
+          'libs/lib1/src/index.ts': '',
+        });
+
+        const result = findFlatConfigFile('libs/lib1', fs.tempDir);
+
+        expect(result).toEqual(join(fs.tempDir, configFile));
+      }
+    );
+  });
+
+  describe('findOldConfigFile', () => {
+    it.each(ESLINT_OLD_CONFIG_FILENAMES)(
+      'should find flat config file "%s" when it exists in the directory',
+      (configFile) => {
+        fs.createFilesSync({
+          [`libs/lib1/${configFile}`]: '',
+        });
+
+        const result = findOldConfigFile('libs/lib1', fs.tempDir);
+
+        expect(result).toEqual(join(fs.tempDir, `libs/lib1/${configFile}`));
+      }
+    );
+
+    it.each(ESLINT_OLD_CONFIG_FILENAMES)(
+      'should find flat config file "%s" when it exists in a parent directory',
+      (configFile) => {
+        fs.createFilesSync({
+          [`libs/${configFile}`]: '',
+          'libs/lib1/src/index.ts': '',
+        });
+
+        const result = findOldConfigFile('libs/lib1', fs.tempDir);
+
+        expect(result).toEqual(join(fs.tempDir, `libs/${configFile}`));
+      }
+    );
+
+    it.each(ESLINT_OLD_CONFIG_FILENAMES)(
+      'should find flat config file "%s" when it exists at the workspace root',
+      (configFile) => {
+        fs.createFilesSync({
+          [configFile]: '',
+          'libs/lib1/src/index.ts': '',
+        });
+
+        const result = findOldConfigFile('libs/lib1', fs.tempDir);
+
+        expect(result).toEqual(join(fs.tempDir, configFile));
+      }
+    );
+  });
+});

packages/eslint/src/utils/config-file.ts

@@ -34,18 +34,17 @@ export function findFlatConfigFile(
 ): string | null {
   let currentDir = resolve(workspaceRoot, directory);
 
-  if (currentDir === workspaceRoot) {
-    return getConfigFileInDirectory(currentDir, ESLINT_FLAT_CONFIG_FILENAMES);
-  }
-
-  while (currentDir !== workspaceRoot) {
+  while (true) {
     const configFilePath = getConfigFileInDirectory(
       currentDir,
       ESLINT_FLAT_CONFIG_FILENAMES
     );
     if (configFilePath) {
       return configFilePath;
     }
+    if (currentDir === workspaceRoot) {
+      break;
+    }
     currentDir = dirname(currentDir);
   }
 
@@ -56,22 +55,22 @@ export function findOldConfigFile(
   filePathOrDirectory: string,
   workspaceRoot: string
 ): string | null {
-  let currentDir = statSync(filePathOrDirectory).isDirectory()
-    ? filePathOrDirectory
-    : dirname(filePathOrDirectory);
-
-  if (currentDir === workspaceRoot) {
-    return getConfigFileInDirectory(currentDir, ESLINT_OLD_CONFIG_FILENAMES);
+  let currentDir = resolve(workspaceRoot, filePathOrDirectory);
+  if (!statSync(currentDir).isDirectory()) {
+    currentDir = dirname(currentDir);
   }
 
-  while (currentDir !== workspaceRoot) {
+  while (true) {
     const configFilePath = getConfigFileInDirectory(
       currentDir,
       ESLINT_OLD_CONFIG_FILENAMES
     );
     if (configFilePath) {
       return configFilePath;
     }
+    if (currentDir === workspaceRoot) {
+      break;
+    }
     currentDir = dirname(currentDir);
   }