Support eslint flat config

packages/eslint-config-airbnb-base/README.md

@@ -60,7 +60,22 @@ Our default export contains all of our ESLint rules, including ECMAScript 6+. It
  npm install --save-dev eslint-config-airbnb-base eslint@^#.#.# eslint-plugin-import@^#.#.#
  ```
 
-2. Add `"extends": "airbnb-base"` to your .eslintrc.
+2. Use it in your eslint config.
+
+ If you use the new flat format, add the following to your eslint.config.js:
+
+ ```javascript
+ const airbnbBase = require('eslint-config-airbnb-base/flat')
+
+ module.exports = [
+ ...airbnbBase,
+ {
+ // any other config
+ }
+ ]
+ ```
+
+ If you still use the regular format: add `"extends": "airbnb-base"` to your .eslintrc.
 
 ### eslint-config-airbnb-base/legacy
 

packages/eslint-config-airbnb-base/flat.js

@@ -0,0 +1,89 @@
+/**
+ * Changes to support the flat config format:
+ * - The `extends` key has been deprecated.
+ * - The `parserOptions` key has been moved under the new `languageOptions` key.
+ * - The `env` key has been deprecated and moved to `languageOptions.globals`.
+ * - The `plugins` key is no longer a list but an object.
+ */
+
+const importPlugin = require('eslint-plugin-import/flat');
+const envs = require('globals');
+const {
+ extends: airbnbRules,
+ ...airbnbConfig
+} = require('.');
+
+const envMapping = {
+ builtin: 'builtin',
+ es5: 'es5',
+ es6: 'es2015',
+ es2016: 'es2015',
+ es2017: 'es2017',
+ es2018: 'es2017',
+ es2019: 'es2017',
+ es2020: 'es2020',
+ es2021: 'es2021',
+ es2022: 'es2021',
+ es2023: 'es2021',
+ es2024: 'es2021',
+ browser: 'browser',
+ worker: 'worker',
+ node: 'node',
+ nodeBuiltin: 'nodeBuiltin',
+ commonjs: 'commonjs',
+ amd: 'amd',
+ mocha: 'mocha',
+ jasmine: 'jasmine',
+ jest: 'jest',
+ qunit: 'qunit',
+ phantomjs: 'phantomjs',
+ couch: 'couch',
+ rhino: 'rhino',
+ nashorn: 'nashorn',
+ wsh: 'wsh',
+ jquery: 'jquery',
+ yui: 'yui',
+ shelljs: 'shelljs',
+ prototypejs: 'prototypejs',
+ meteor: 'meteor',
+ mongo: 'mongo',
+ applescript: 'applescript',
+ serviceworker: 'serviceworker',
+ atomtest: 'atomtest',
+ embertest: 'embertest',
+ protractor: 'protractor',
+ 'shared-node-browser': 'shared-node-browser',
+ webextensions: 'webextensions',
+ greasemonkey: 'greasemonkey',
+ devtools: 'devtools',
+};
+
+function convertIntoEslintFlatConfig(config) {
+ const {
+ env, // convert to explicit `globals` list
+ parserOptions, // move into `languageOptions`
+ plugins, // remove the `plugins` key as it will be spread directly during export
+ ...oldConfig
+ } = config;
+ return {
+ ...oldConfig,
+ languageOptions: {
+ ...('env' in config && {
+ globals: Object.fromEntries(
+ Object.keys(env)
+ .filter((key) => env[key] === true && key in envMapping && envMapping[key] in envs)
+ .flatMap((key) => Object.entries(envs[envMapping[key]]))
+ ),
+ ...('parserOptions' in config && {
+ parserOptions,
+ }),
+ }),
+ },
+ };
+}
+
+module.exports = [
+ ...airbnbRules.map((rule) => convertIntoEslintFlatConfig(require(rule))),
+ convertIntoEslintFlatConfig(airbnbConfig),
+ ...importPlugin,
+];

packages/eslint-config-airbnb-base/package.json

@@ -5,6 +5,7 @@
  "main": "index.js",
  "exports": {
  ".": "./index.js",
+ "./flat": "./flat.js",
  "./legacy": "./legacy.js",
  "./whitespace": "./whitespace.js",
  "./rules/best-practices": "./rules/best-practices.js",
@@ -88,6 +89,7 @@
  },
  "dependencies": {
  "confusing-browser-globals": "^1.0.11",
+ "globals": "^13.21.0",
  "object.entries": "^1.1.6"
  }
 }

packages/eslint-config-airbnb-base/rules/imports.js

@@ -91,7 +91,8 @@ module.exports = {
  '**/protractor.conf.js', // protractor config
  '**/protractor.conf.*.js', // protractor config
  '**/karma.conf.js', // karma config
- '**/.eslintrc.js' // eslint config
+ '**/.eslintrc.js', // eslint config
+ '**/eslint.config.js', // eslint flat config
  ],
  optionalDependencies: false,
  }],