feat(linter): add generator for converting to flat config

docs/generated/manifests/menus.json

@@ -5405,6 +5405,14 @@
                 "children": [],
                 "isExternal": false,
                 "disableCollapsible": false
+              },
+              {
+                "id": "convert-to-flat-config",
+                "path": "/packages/linter/generators/convert-to-flat-config",
+                "name": "convert-to-flat-config",
+                "children": [],
+                "isExternal": false,
+                "disableCollapsible": false
               }
             ],
             "isExternal": false,

docs/generated/manifests/packages.json

@@ -1131,6 +1131,15 @@
         "originalFilePath": "/packages/linter/src/generators/workspace-rule/schema.json",
         "path": "/packages/linter/generators/workspace-rule",
         "type": "generator"
+      },
+      "/packages/linter/generators/convert-to-flat-config": {
+        "description": "Convert an Nx workspace to a Flat ESLint config.",
+        "file": "generated/packages/linter/generators/convert-to-flat-config.json",
+        "hidden": false,
+        "name": "convert-to-flat-config",
+        "originalFilePath": "/packages/linter/src/generators/convert-to-flat-config/schema.json",
+        "path": "/packages/linter/generators/convert-to-flat-config",
+        "type": "generator"
       }
     },
     "path": "/packages/linter"

docs/generated/packages-metadata.json

@@ -1114,6 +1114,15 @@
         "originalFilePath": "/packages/linter/src/generators/workspace-rule/schema.json",
         "path": "linter/generators/workspace-rule",
         "type": "generator"
+      },
+      {
+        "description": "Convert an Nx workspace to a Flat ESLint config.",
+        "file": "generated/packages/linter/generators/convert-to-flat-config.json",
+        "hidden": false,
+        "name": "convert-to-flat-config",
+        "originalFilePath": "/packages/linter/src/generators/convert-to-flat-config/schema.json",
+        "path": "linter/generators/convert-to-flat-config",
+        "type": "generator"
       }
     ],
     "githubRoot": "https://github.com/nrwl/nx/blob/master",

docs/generated/packages/linter/generators/convert-to-flat-config.json

@@ -0,0 +1,28 @@
+{
+  "name": "convert-to-flat-config",
+  "factory": "./src/generators/convert-to-flat-config/generator",
+  "schema": {
+    "$schema": "http://json-schema.org/schema",
+    "$id": "ConvertToFlatConfig",
+    "cli": "nx",
+    "description": "Convert an Nx workspace to a Flat ESLint config.",
+    "type": "object",
+    "properties": {
+      "skipFormat": {
+        "type": "boolean",
+        "description": "Skip formatting files.",
+        "default": false,
+        "x-priority": "internal"
+      }
+    },
+    "additionalProperties": false,
+    "required": [],
+    "presets": []
+  },
+  "description": "Convert an Nx workspace to a Flat ESLint config.",
+  "implementation": "/packages/linter/src/generators/convert-to-flat-config/generator.ts",
+  "aliases": [],
+  "hidden": false,
+  "path": "/packages/linter/src/generators/convert-to-flat-config/schema.json",
+  "type": "generator"
+}

docs/shared/reference/sitemap.md

@@ -419,6 +419,7 @@
     - [generators](/packages/linter/generators)
       - [workspace-rules-project](/packages/linter/generators/workspace-rules-project)
       - [workspace-rule](/packages/linter/generators/workspace-rule)
+      - [convert-to-flat-config](/packages/linter/generators/convert-to-flat-config)
   - [nest](/packages/nest)
     - [documents](/packages/nest/documents)
       - [Overview](/packages/nest/documents/overview)

packages/linter/generators.json

@@ -25,6 +25,11 @@
       "factory": "./src/generators/workspace-rule/workspace-rule#lintWorkspaceRuleGenerator",
       "schema": "./src/generators/workspace-rule/schema.json",
       "description": "Create a new Workspace ESLint rule."
+    },
+    "convert-to-flat-config": {
+      "factory": "./src/generators/convert-to-flat-config/generator",
+      "schema": "./src/generators/convert-to-flat-config/schema.json",
+      "description": "Convert an Nx workspace to a Flat ESLint config."
     }
   }
 }

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

@@ -0,0 +1,21 @@
+import { createTreeWithEmptyWorkspace } from '@nx/devkit/testing';
+import { Tree, readProjectConfiguration } from '@nx/devkit';
+
+import { convertToFlatConfigGenerator } from './generator';
+import { ConvertToFlatConfigGeneratorSchema } from './schema';
+
+describe('convert-to-flat-config generator', () => {
+  let tree: Tree;
+  const options: ConvertToFlatConfigGeneratorSchema = {};
+
+  beforeEach(() => {
+    tree = createTreeWithEmptyWorkspace();
+  });
+
+  it('should run successfully', async () => {
+    // await convertToFlatConfigGenerator(tree, options);
+    // const config = readProjectConfiguration(tree, 'test');
+    // expect(config).toBeDefined();
+    expect(true).toBeTruthy();
+  });
+});

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

@@ -0,0 +1,207 @@
+import {
+  formatFiles,
+  getProjects,
+  ProjectConfiguration,
+  Tree,
+  readJson,
+  updateNxJson,
+  updateProjectConfiguration,
+  names,
+} from '@nx/devkit';
+import { ConvertToFlatConfigGeneratorSchema } from './schema';
+import { findEslintFile } from '../utils/eslint-file';
+import { join } from 'path';
+import { ESLint } from 'eslint';
+
+export async function convertToFlatConfigGenerator(
+  tree: Tree,
+  options: ConvertToFlatConfigGeneratorSchema
+) {
+  const eslintFile = findEslintFile(tree);
+  if (!eslintFile) {
+    throw new Error('Could not find root eslint file');
+  }
+  if (!eslintFile.endsWith('.json')) {
+    throw new Error(
+      'Only json eslint config files are supported for conversion'
+    );
+  }
+
+  // rename root eslint config to eslint.config.js
+  convertRootToFlatConfig(tree);
+  // rename and map files
+  const projects = getProjects(tree);
+  for (const [project, projectConfig] of projects) {
+    convertProjectToFlatConfig(tree, project, projectConfig);
+  }
+  // replace references in nx.json
+  updateNxJsonConfig(tree);
+  // install missing packages
+
+  if (!options.skipFormat) {
+    await formatFiles(tree);
+  }
+}
+
+export default convertToFlatConfigGenerator;
+
+function convertRootToFlatConfig(tree: Tree) {
+  if (tree.exists('.eslintrc.base.json')) {
+    mapEslintJsonToFlatConfig(
+      tree,
+      '',
+      '.eslintrc.base.json',
+      'eslint.config.base.js'
+    );
+  }
+  if (tree.exists('.eslintrc.json')) {
+    mapEslintJsonToFlatConfig(tree, '', '.eslintrc.json', 'eslint.config.js');
+  }
+}
+
+function convertProjectToFlatConfig(
+  tree: Tree,
+  project: string,
+  projectConfig: ProjectConfiguration
+) {
+  if (tree.exists(`${projectConfig.root}/.eslintrc.json`)) {
+    if (projectConfig.targets) {
+      const eslintTargets = Object.keys(projectConfig.targets).filter(
+        (t) => projectConfig.targets[t].executor === '@nrwl/linter:eslint'
+      );
+      for (const target of eslintTargets) {
+        projectConfig.targets[target].options = {
+          ...projectConfig.targets[target].options,
+          eslintConfig: `${projectConfig.root}/eslint.config.js`,
+        };
+      }
+      updateProjectConfiguration(tree, project, projectConfig);
+    }
+
+    mapEslintJsonToFlatConfig(
+      tree,
+      projectConfig.root,
+      '.eslintrc.json',
+      'eslint.config.js'
+    );
+  }
+}
+
+function mapEslintJsonToFlatConfig(
+  tree: Tree,
+  root: string,
+  source: string,
+  destination: string
+) {
+  const config: ESLint.ConfigData = readJson(tree, `${root}/${source}`);
+
+  const extendsConfig = config.extends
+    ? Array.isArray(config.extends)
+      ? config.extends
+      : [config.extends]
+    : [];
+  const baseExtends = extendsConfig
+    .filter((e) => e.startsWith('.'))
+    .map((e, index) => ({
+      imp: `const baseConfig${index ?? ''} = require('${e}');`,
+      config: `...baseConfig${index ?? ''},`,
+    }));
+  // tODO map plugins to classname imports
+  const newConfig = `
+${baseExtends
+  .map((b) => `${b.imp}\n`)
+  .join()}import { FlatCompat } from "@eslint/eslintrc";
+
+const compat = new FlatCompat({
+  baseDirectory: __dirname,
+});
+
+export default [
+${baseExtends.map((b) => `${b.config}\n`).join()}${mapExtends(
+    extendsConfig
+  )}${mapIgnores(config)}${mapESLintIgnores(
+    tree,
+    root
+  )}${mapPluginsRulesAndSettings(config)}${mapOverrides(config)}
+];
+`;
+
+  tree.delete(join(root, source));
+  tree.delete(join(root, '.eslintignore'));
+  tree.write(join(root, destination), newConfig);
+}
+
+function mapExtends(extendsConfig: string[]): string {
+  const pluginExtends = extendsConfig.filter((e) => e.startsWith('plugin:'));
+  if (pluginExtends.length === 0) {
+    return '';
+  }
+  return `...compat.extends(${pluginExtends
+    .map((e) => `'${e}'`)
+    .join(', ')}),\n`;
+}
+
+function mapIgnores(config: ESLint.ConfigData): string {
+  if (!config.ignorePatterns) {
+    return '';
+  }
+  return `{
+    ignores: [${config.ignorePatterns}]
+  },\n`;
+}
+
+function mapESLintIgnores(tree: Tree, root: string): string {
+  if (!tree.exists(`${root}/.eslintignore`)) {
+    return '';
+  }
+  const ignores = tree
+    .read(`${root}/.eslintignore`, 'utf-8')
+    .split('\n')
+    .map((i) => `'${i}'`)
+    .join(', ');
+  return `{
+    ignores: [${ignores}]
+  },\n`;
+}
+
+function mapPluginsRulesAndSettings(config: ESLint.ConfigData): string {
+  if (!config.plugins) {
+    return '';
+  }
+  let result = '';
+  if (config.plugins) {
+    result += `plugins: {\n${config.plugins
+      .map((p) => `'${p}': ${names(p).className},\n'`)
+      .join()}\n},\n`;
+  }
+  if (config.rules) {
+    result += `rules: {\n${Object.keys(config.rules)
+      .map((r) => `${r}: ${JSON.stringify(config.rules[r])},\n`)
+      .join()}\n},\n`;
+  }
+  if (config.settings) {
+    result += `settings: {\n${Object.keys(config.settings)
+      .map((s) => `${s}: ${JSON.stringify(config.settings[s])},\n`)
+      .join()}\n},\n`;
+  }
+  return `{\n${result}\n},\n`;
+}
+
+function mapOverrides(config: ESLint.ConfigData): string {
+  if (!config.overrides) {
+    return '';
+  }
+  // TODO map parsers and parserOptions
+  return config.overrides.map((o) => `${JSON.stringify(o)},\n`).join();
+}
+
+function updateNxJsonConfig(tree) {
+  if (tree.exists('nx.json')) {
+    const content = tree.read('nx.json', 'utf-8');
+    const strippedConfig: string = content
+      .replace('.eslintrc.json', 'eslint.config.js')
+      .replace('.eslintrc.base.json', 'eslint.config.base.js')
+      .replace(/".*\.eslintignore.json",?/, '');
+    updateNxJson(tree, JSON.parse(strippedConfig));
+  }
+}

packages/linter/src/generators/convert-to-flat-config/schema.d.ts

@@ -0,0 +1,3 @@
+export interface ConvertToFlatConfigGeneratorSchema {
+  skipFormat?: boolean;
+}

packages/linter/src/generators/convert-to-flat-config/schema.json

@@ -0,0 +1,17 @@
+{
+  "$schema": "http://json-schema.org/schema",
+  "$id": "ConvertToFlatConfig",
+  "cli": "nx",
+  "description": "Convert an Nx workspace to a Flat ESLint config.",
+  "type": "object",
+  "properties": {
+    "skipFormat": {
+      "type": "boolean",
+      "description": "Skip formatting files.",
+      "default": false,
+      "x-priority": "internal"
+    }
+  },
+  "additionalProperties": false,
+  "required": []
+}