fix(linter): migrate custom ignorePath to flat config (#20017)

packages/eslint/src/generators/convert-to-flat-config/__snapshots__/generator.spec.ts.snap

@@ -135,7 +135,7 @@ module.exports = [
 "
 `;
 
-exports[`convert-to-flat-config generator should add global gitignores 1`] = `
+exports[`convert-to-flat-config generator should add global eslintignores 1`] = `
 "const { FlatCompat } = require('@eslint/eslintrc');
 const nxEslintPlugin = require('@nx/eslint-plugin');
 const js = require('@eslint/js');
@@ -317,6 +317,33 @@ module.exports = [
 "
 `;
 
+exports[`convert-to-flat-config generator should handle custom eslintignores 1`] = `
+"const baseConfig = require('../../eslint.config.js');
+module.exports = [
+  ...baseConfig,
+  {
+    files: [
+      'libs/test-lib/**/*.ts',
+      'libs/test-lib/**/*.tsx',
+      'libs/test-lib/**/*.js',
+      'libs/test-lib/**/*.jsx',
+    ],
+    rules: {},
+  },
+  {
+    files: ['libs/test-lib/**/*.ts', 'libs/test-lib/**/*.tsx'],
+    rules: {},
+  },
+  {
+    files: ['libs/test-lib/**/*.js', 'libs/test-lib/**/*.jsx'],
+    rules: {},
+  },
+  { ignores: ['libs/test-lib/ignore/me'] },
+  { ignores: ['libs/test-lib/ignore/me/as/well'] },
+];
+"
+`;
+
 exports[`convert-to-flat-config generator should run successfully 1`] = `
 "const { FlatCompat } = require('@eslint/eslintrc');
 const nxEslintPlugin = require('@nx/eslint-plugin');

packages/eslint/src/generators/convert-to-flat-config/converters/json-converter.spec.ts

@@ -62,7 +62,8 @@ describe('convertEslintJsonToFlatConfig', () => {
       tree,
       '',
       '.eslintrc.json',
-      'eslint.config.js'
+      'eslint.config.js',
+      ['.eslintignore']
     );
 
     expect(tree.read('eslint.config.js', 'utf-8')).toMatchInlineSnapshot(`
@@ -119,7 +120,6 @@ describe('convertEslintJsonToFlatConfig', () => {
     `);
 
     expect(tree.exists('.eslintrc.json')).toBeFalsy();
-    expect(tree.exists('.eslintignore')).toBeFalsy();
   });
 
   it('should convert project configs', async () => {
@@ -174,7 +174,8 @@ describe('convertEslintJsonToFlatConfig', () => {
       tree,
       'mylib',
       '.eslintrc.json',
-      'eslint.config.js'
+      'eslint.config.js',
+      ['mylib/.eslintignore']
     );
 
     expect(tree.read('mylib/eslint.config.js', 'utf-8')).toMatchInlineSnapshot(`
@@ -229,6 +230,5 @@ describe('convertEslintJsonToFlatConfig', () => {
     `);
 
     expect(tree.exists('mylib/.eslintrc.json')).toBeFalsy();
-    expect(tree.exists('mylib/.eslintignore')).toBeFalsy();
   });
 });

packages/eslint/src/generators/convert-to-flat-config/converters/json-converter.ts

@@ -27,7 +27,8 @@ export function convertEslintJsonToFlatConfig(
   tree: Tree,
   root: string,
   sourceFile: string,
-  destinationFile: string
+  destinationFile: string,
+  ignorePaths: string[]
 ) {
   const importsMap = new Map<string, string>();
   const exportElements: ts.Expression[] = [];
@@ -174,19 +175,20 @@ export function convertEslintJsonToFlatConfig(
     }
   }
 
-  if (tree.exists(`${root}/.eslintignore`)) {
-    const patterns = tree
-      .read(`${root}/.eslintignore`, 'utf-8')
-      .split('\n')
-      .filter((line) => line.length > 0 && line !== 'node_modules')
-      .map((path) => mapFilePath(path, root));
-    if (patterns.length > 0) {
-      exportElements.push(generateAst({ ignores: patterns }));
+  for (const ignorePath of ignorePaths) {
+    if (tree.exists(ignorePath)) {
+      const patterns = tree
+        .read(ignorePath, 'utf-8')
+        .split('\n')
+        .filter((line) => line.length > 0 && line !== 'node_modules')
+        .map((path) => mapFilePath(path, root));
+      if (patterns.length > 0) {
+        exportElements.push(generateAst({ ignores: patterns }));
+      }
     }
   }
 
   tree.delete(join(root, sourceFile));
-  tree.delete(join(root, '.eslintignore'));
 
   // create the node list and print it to new file
   const nodeList = createNodeList(

packages/eslint/src/generators/convert-to-flat-config/generator.spec.ts

@@ -12,6 +12,7 @@ import { ConvertToFlatConfigGeneratorSchema } from './schema';
 import { lintProjectGenerator } from '../lint-project/lint-project';
 import { Linter } from '../utils/linter';
 import { eslintrcVersion } from '../../utils/versions';
+import { read } from 'fs';
 
 describe('convert-to-flat-config generator', () => {
   let tree: Tree;
@@ -153,7 +154,7 @@ describe('convert-to-flat-config generator', () => {
     ).toEqual(eslintrcVersion);
   });
 
-  it('should add global gitignores', async () => {
+  it('should add global eslintignores', async () => {
     await lintProjectGenerator(tree, {
       skipFormat: false,
       linter: Linter.EsLint,
@@ -164,7 +165,39 @@ describe('convert-to-flat-config generator', () => {
     tree.write('.eslintignore', 'ignore/me');
     await convertToFlatConfigGenerator(tree, options);
 
-    expect(tree.read('eslint.config.js', 'utf-8')).toMatchSnapshot();
+    const config = tree.read('eslint.config.js', 'utf-8');
+    expect(config).toContain('ignore/me');
+    expect(config).toMatchSnapshot();
+    expect(tree.exists('.eslintignore')).toBeFalsy();
+  });
+
+  it('should handle custom eslintignores', async () => {
+    await lintProjectGenerator(tree, {
+      skipFormat: false,
+      linter: Linter.EsLint,
+      eslintFilePatterns: ['**/*.ts'],
+      project: 'test-lib',
+      setParserOptionsProject: false,
+    });
+    tree.write('another-folder/.myeslintignore', 'ignore/me');
+    updateJson(tree, 'libs/test-lib/project.json', (json) => {
+      json.targets.lint.options.ignorePath = 'another-folder/.myeslintignore';
+      return json;
+    });
+    tree.write('libs/test-lib/.eslintignore', 'ignore/me/as/well');
+
+    await convertToFlatConfigGenerator(tree, options);
+
+    expect(
+      tree.read('libs/test-lib/eslint.config.js', 'utf-8')
+    ).toMatchSnapshot();
+    expect(tree.exists('another-folder/.myeslintignore')).toBeFalsy();
+    expect(tree.exists('libs/test-lib/.eslintignore')).toBeFalsy();
+
+    expect(
+      readJson(tree, 'libs/test-lib/project.json').targets.lint.options
+        .ignorePath
+    ).toBeUndefined();
   });
 
   it('should add settings', async () => {

packages/eslint/src/generators/convert-to-flat-config/generator.ts

@@ -26,13 +26,28 @@ export async function convertToFlatConfigGenerator(
     );
   }
 
-  // rename root eslint config to eslint.config.js
+  const eslintIgnoreFiles = new Set<string>(['.eslintignore']);
+
+  // convert root eslint config to eslint.config.js
   convertRootToFlatConfig(tree, eslintFile);
-  // rename and map files
+
+  // convert project eslint files to eslint.config.js
   const projects = getProjects(tree);
   for (const [project, projectConfig] of projects) {
-    convertProjectToFlatConfig(tree, project, projectConfig, readNxJson(tree));
+    convertProjectToFlatConfig(
+      tree,
+      project,
+      projectConfig,
+      readNxJson(tree),
+      eslintIgnoreFiles
+    );
   }
+
+  // delete all .eslintignore files
+  for (const ignoreFile of eslintIgnoreFiles) {
+    tree.delete(ignoreFile);
+  }
+
   // replace references in nx.json
   updateNxJsonConfig(tree);
   // install missing packages
@@ -60,18 +75,24 @@ function convertProjectToFlatConfig(
   tree: Tree,
   project: string,
   projectConfig: ProjectConfiguration,
-  nxJson: NxJsonConfiguration
+  nxJson: NxJsonConfiguration,
+  eslintIgnoreFiles: Set<string>
 ) {
   if (tree.exists(`${projectConfig.root}/.eslintrc.json`)) {
     if (projectConfig.targets) {
       const eslintTargets = Object.keys(projectConfig.targets || {}).filter(
         (t) => projectConfig.targets[t].executor === '@nx/eslint:lint'
       );
+      let ignorePath: string | undefined;
       for (const target of eslintTargets) {
         // remove any obsolete `eslintConfig` options pointing to the old config file
         if (projectConfig.targets[target].options?.eslintConfig) {
           delete projectConfig.targets[target].options.eslintConfig;
         }
+        if (projectConfig.targets[target].options?.ignorePath) {
+          ignorePath = projectConfig.targets[target].options.ignorePath;
+          delete projectConfig.targets[target].options.ignorePath;
+        }
         updateProjectConfiguration(tree, project, projectConfig);
       }
       const nxHasLintTargets = Object.keys(nxJson.targetDefaults || {}).some(
@@ -85,8 +106,13 @@ function convertProjectToFlatConfig(
           tree,
           projectConfig.root,
           '.eslintrc.json',
-          'eslint.config.js'
+          'eslint.config.js',
+          ignorePath
         );
+        eslintIgnoreFiles.add(`${projectConfig.root}/.eslintignore`);
+        if (ignorePath) {
+          eslintIgnoreFiles.add(ignorePath);
+        }
       }
     }
   }
@@ -121,7 +147,11 @@ function convertConfigToFlatConfig(
   tree: Tree,
   root: string,
   source: string,
-  target: string
+  target: string,
+  ignorePath?: string
 ) {
-  convertEslintJsonToFlatConfig(tree, root, source, target);
+  const ignorePaths = ignorePath
+    ? [ignorePath, `${root}/.eslintignore`]
+    : [`${root}/.eslintignore`];
+  convertEslintJsonToFlatConfig(tree, root, source, target, ignorePaths);
 }