Migrate to flat config

.github/workflows/main.yml

@@ -10,9 +10,9 @@ jobs:
       fail-fast: false
       matrix:
         node-version:
-          - 16
-          - 14
-          - 12
+          - 22
+          - 20
+          - 18
     steps:
       - uses: actions/checkout@v4
       - uses: actions/setup-node@v4

browser.js

@@ -1,17 +1,25 @@
-'use strict';
-const path = require('path');
-const confusingBrowserGlobals = require('confusing-browser-globals');
+import globals from 'globals';
+import confusingBrowserGlobals from 'confusing-browser-globals';
+import eslintConfigXo from './index.js';
 
-module.exports = {
-	extends: path.join(__dirname, 'index.js'),
-	env: {
-		node: false,
-		browser: true,
-	},
-	rules: {
-		'no-restricted-globals': [
-			'error',
-			...confusingBrowserGlobals,
-		],
+const [config] = eslintConfigXo;
+
+export default [
+	{
+		...config,
+		languageOptions: {
+			...config.languageOptions,
+			globals: {
+				...globals.es2021,
+				...globals.browser,
+			},
+		},
+		rules: {
+			...config.rules,
+			'no-restricted-globals': [
+				'error',
+				...confusingBrowserGlobals,
+			],
+		},
 	},
-};
+];

eslint.config.js

@@ -0,0 +1 @@
+export {default} from './index.js';

index.js

@@ -1,18 +1,21 @@
-'use strict';
+import globals from 'globals';
 
-module.exports = {
-	parserOptions: {
-		ecmaVersion: 'latest',
+const config = {
+	languageOptions: {
 		sourceType: 'module',
-		ecmaFeatures: {
-			jsx: true,
+		parserOptions: {
+			ecmaFeatures: {
+				jsx: true,
+			},
+		},
+		globals: {
+			...globals.es2021,
+			...globals.node,
 		},
 	},
-	env: {
-		es2021: true,
-		node: true,
+	linterOptions: {
+		reportUnusedDisableDirectives: 'error',
 	},
-	reportUnusedDisableDirectives: true,
 	rules: {
 		'comma-dangle': [
 			'error',
@@ -204,7 +207,7 @@
 		radix: 'error',
 
 		// Disabled for now as it causes too much churn
 		// TODO: Enable it in the future when I have time to deal with
 		// the churn and the rule is stable and has an autofixer.
 		// Still doesn't have a fixer as of ESLint 7.24.0.
 		// 'require-unicode-regexp': 'error',
@@ -222,7 +225,7 @@
 		'no-restricted-globals': [
 			'error',
 			'event',
 			// TODO: Enable this in 2025.
 			// {
 			// 	name: 'Buffer',
 			// 	message: 'Use Uint8Array instead. See: https://sindresorhus.com/blog/goodbye-nodejs-buffer',
@@ -266,7 +269,7 @@
 			'sys',
 			'querystring',
 			'colors',
 			// TODO: Enable this in 2025.
 			// {
 			// 	name: 'buffer',
 			// 	message: 'Use Uint8Array instead. See: https://sindresorhus.com/blog/goodbye-nodejs-buffer',
@@ -637,7 +640,7 @@
 			{
 				// `array` is disabled because it forces destructuring on
 				// stupid stuff like `foo.bar = process.argv[2];`
 				// TODO: Open ESLint issue about this
 				VariableDeclarator: {
 					array: false,
 					object: true,
@@ -671,3 +674,5 @@
 		],
 	},
 };
+
+export default [config];

package.json

@@ -3,6 +3,13 @@
 	"version": "0.45.0",
 	"description": "ESLint shareable config for XO",
 	"license": "MIT",
+	"type": "module",
+	"exports": {
+		".": "./index.js",
+		"./browser": "./browser.js",
+		"./space": "./space.js",
+		"./space/browser": "./space-browser.js"
+	},
 	"repository": "xojs/eslint-config-xo",
 	"funding": "https://github.com/sponsors/sindresorhus",
 	"author": {
@@ -19,7 +26,9 @@
 	},
 	"files": [
 		"index.js",
-		"browser.js"
+		"browser.js",
+		"space.js",
+		"space-browser.js"
 	],
 	"keywords": [
 		"eslintconfig",
@@ -50,12 +59,12 @@
 		"simple"
 	],
 	"dependencies": {
-		"confusing-browser-globals": "1.0.11"
+		"confusing-browser-globals": "1.0.11",
+		"globals": "^15.3.0"
 	},
 	"devDependencies": {
-		"ava": "^2.4.0",
-		"eslint": "^8.56.0",
-		"is-plain-obj": "^3.0.0"
+		"ava": "^6.1.3",
+		"eslint": "^9.4.0"
 	},
 	"peerDependencies": {
 		"eslint": ">=8.56.0"

readme.md

@@ -16,31 +16,44 @@ npm install --save-dev eslint-config-xo
 
 ## Usage
 
-Add some ESLint config to your `package.json`:
-
-```json
-{
-	"name": "my-awesome-project",
-	"eslintConfig": {
-		"extends": "xo"
-	}
-}
+Add some ESLint config to your `eslint.config.js`:
+
+```js
+import eslintConfigXo from 'eslint-config-xo';
+
+export default [
+	...eslintConfigXo,
+];
+```
+
+This package also exposes [`eslint-config-xo/browser`](browser.js) if you're in the browser:
+
+```js
+import eslintConfigXoBrowser from 'eslint-config-xo/browser';
+
+export default [
+	...eslintConfigXoBrowser,
+];
 ```
 
-Or to `.eslintrc`:
+This package also exposes [`eslint-config-xo/space`](space.js) if you're in favor of 2-space indent:
 
-```json
-{
-	"extends": "xo"
-}
+```js
+import eslintConfigXoSpace from 'eslint-config-xo/space';
+
+export default [
+	...eslintConfigXoSpace,
+];
 ```
 
-This package also exposes [`xo/browser`](browser.js) if you're in the browser:
+This package also exposes [`eslint-config-xo/space/browser`](space-browser.js) if you're in favor of 2-space indent and in browser:
+
+```js
+import eslintConfigXoSpaceBrowser from 'eslint-config-xo/space/browser';
 
-```json
-{
-	"extends": "xo/browser"
-}
+export default [
+	...eslintConfigXoSpaceBrowser,
+];
 ```
 
 ## Use the XO CLI instead

space-browser.js

@@ -0,0 +1,19 @@
+import eslintConfigXoBrowser from './browser.js';
+
+const [config] = eslintConfigXoBrowser;
+
+export default [
+	{
+		...config,
+		rules: {
+			...config.rules,
+			indent: [
+				'error',
+				2,
+				{
+					SwitchCase: 1,
+				},
+			],
+		},
+	},
+];

space.js

@@ -0,0 +1,19 @@
+import eslintConfigXo from './index.js';
+
+const [config] = eslintConfigXo;
+
+export default [
+	{
+		...config,
+		rules: {
+			...config.rules,
+			indent: [
+				'error',
+				2,
+				{
+					SwitchCase: 1,
+				},
+			],
+		},
+	},
+];

test/test.js

@@ -1,12 +1,15 @@
 import test from 'ava';
-import isPlainObj from 'is-plain-obj';
 import {ESLint} from 'eslint';
+import eslintConfigXoNode from '../index.js';
+import eslintConfigXoBrowser from '../browser.js';
+import eslintConfigXoSpaceNode from '../space.js';
+import eslintConfigXoSpaceBrowser from '../space-browser.js';
 
 const hasRule = (errors, ruleId) => errors.some(error => error.ruleId === ruleId);
 
 async function runEslint(string, config) {
 	const eslint = new ESLint({
-		useEslintrc: false,
+		overrideConfigFile: true,
 		overrideConfig: config,
 	});
 
@@ -15,21 +18,56 @@ async function runEslint(string, config) {
 	return firstResult.messages;
 }
 
-test('main', async t => {
-	const config = require('../index.js');
+test('node', async t => {
+	for (const config of [eslintConfigXoNode, eslintConfigXoSpaceNode]) {
+		t.true(Array.isArray(config));
 
-	t.true(isPlainObj(config));
-	t.true(isPlainObj(config.rules));
-
-	const errors = await runEslint('\'use strict\';\nconsole.log("unicorn")\n', config);
-	t.true(hasRule(errors, 'quotes'), JSON.stringify(errors));
+		// eslint-disable-next-line no-await-in-loop
+		const errors = await runEslint('\'use strict\';\nconsole.log("unicorn")\n', config);
+		t.true(hasRule(errors, 'quotes'), JSON.stringify(errors));
+	}
 });
 
 test('browser', async t => {
-	const config = require('../browser.js');
+	for (const config of [eslintConfigXoBrowser, eslintConfigXoSpaceBrowser]) {
+		t.true(Array.isArray(config));
+
+		// eslint-disable-next-line no-await-in-loop
+		const errors = await runEslint('\'use strict\';\nprocess.exit();\n', config);
+		t.true(hasRule(errors, 'no-undef'), JSON.stringify(errors));
+	}
+});
 
-	t.true(isPlainObj(config));
+test('space', async t => {
+	const fixture = `
+export function foo() {
+\treturn true;
+}
+`.trim();
 
-	const errors = await runEslint('\'use strict\';\nprocess.exit();\n', config);
-	t.true(hasRule(errors, 'no-undef'), JSON.stringify(errors));
+	for (const {
+		expected,
+		config,
+	} of [
+			{
+				config: eslintConfigXoSpaceNode,
+				expected: true,
+			},
+			{
+				config: eslintConfigXoSpaceBrowser,
+				expected: true,
+			},
+			{
+				config: eslintConfigXoNode,
+				expected: false,
+			},
+			{
+				config: eslintConfigXoBrowser,
+				expected: false,
+			},
+		]) {
+		// eslint-disable-next-line no-await-in-loop
+		const errors = await runEslint(fixture, config);
+		t.is(hasRule(errors, 'indent'), expected, JSON.stringify(errors));
+	}
 });