Require Node.js 22

Author: sindresorhus

.github/workflows/main.yml

@@ -12,15 +12,10 @@ jobs:
         node-version:
           - 24
           - 22
-          - 20
     steps:
-      - uses: actions/checkout@v4
-      - uses: actions/setup-node@v4
+      - uses: actions/checkout@v6
+      - uses: actions/setup-node@v6
         with:
           node-version: ${{ matrix.node-version }}
       - run: npm install
       - run: npm test
-      # - uses: codecov/codecov-action@v1
-      #   if: matrix.node-version == 14
-      #   with:
-      #     fail_ci_if_error: true

lib/utils.ts

@@ -93,11 +93,8 @@ Validate an XO config array for legacy ESLint config properties that are not sup
 @param xoConfig - The flat XO config to validate.
 */
 export const validateXoConfig = (xoConfig: XoConfigItem[]): void => {
-	for (const [index, config] of xoConfig.entries()) {
-		if (index === 0) {
-			continue; // Skip internal base config prepended by XO
-		}
-
+	// Skip the first item (internal base config prepended by XO)
+	for (const config of xoConfig.values().drop(1)) {
 		for (const key of Object.keys(config)) {
 			const hint = legacyPropertyHints[key];
 			if (hint) {
@@ -122,18 +119,13 @@ export const preProcessXoConfig = (xoConfig: XoConfigItem[]): {config: XoConfigI
 	const tsFilesGlob: string[] = [];
 	const tsFilesIgnoresGlob: string[] = [];
 
-	const processedConfig: XoConfigItem[] = [];
+	// The first config item is the internal base config; push it through unmodified.
+	const processedConfig: XoConfigItem[] = xoConfig[0] ? [{...xoConfig[0]}] : [];
 
-	for (const [idx, {...config}] of xoConfig.entries()) {
+	for (const {...config} of xoConfig.values().drop(1)) {
 		const languageOptions = config.languageOptions as Linter.LanguageOptions | undefined;
 		const parserOptions = languageOptions?.parserOptions as TypeScriptParserOptions | undefined;
 
-		// We can skip the first config item, as it is the base config item.
-		if (idx === 0) {
-			processedConfig.push(config);
-			continue;
-		}
-
 		// Use TS parser/plugin for JS files if the config contains TypeScript rules which are applied to JS files.
 		// typescript-eslint rules set to "off" are ignored and not applied to JS files.
 		if (

lib/xo.ts

@@ -675,7 +675,7 @@ export class Xo {
 			});
 
 			if (nextVirtualFiles.size > 0) {
-				const filesArray = [...nextVirtualFiles];
+				const filesArray = nextVirtualFiles.values().toArray();
 				const relativeFiles = filesArray.map(file => path.relative(this._linterOptions.cwd, file));
 
 				const tsconfigContent = {

package.json

@@ -18,7 +18,7 @@
 	},
 	"sideEffects": false,
 	"engines": {
-		"node": ">=20.19"
+		"node": ">=22"
 	},
 	"scripts": {
 		"build": "npm run clean && tsc",
@@ -67,10 +67,10 @@
 		"typescript"
 	],
 	"dependencies": {
-		"@eslint/compat": "^2.0.2",
+		"@eslint/compat": "^2.0.3",
 		"@sindresorhus/tsconfig": "^8.1.0",
 		"arrify": "^3.0.0",
-		"cosmiconfig": "^9.0.0",
+		"cosmiconfig": "^9.0.1",
 		"define-lazy-prop": "^3.0.0",
 		"eslint": "^10.1.0",
 		"eslint-config-prettier": "^10.1.8",
@@ -80,22 +80,22 @@
 		"eslint-plugin-prettier": "^5.5.5",
 		"find-cache-directory": "^6.0.0",
 		"get-stdin": "^10.0.0",
-		"get-tsconfig": "^4.13.6",
+		"get-tsconfig": "^4.13.7",
 		"globby": "^16.2.0",
-		"jiti": "^2.2.0",
+		"jiti": "^2.6.1",
 		"meow": "^14.1.0",
 		"micromatch": "^4.0.8",
 		"open-editor": "^6.0.0",
 		"path-exists": "^5.0.0",
 		"prettier": "^3.8.1",
-		"type-fest": "^5.4.3",
+		"type-fest": "^5.5.0",
 		"typescript": "^6.0.2"
 	},
 	"devDependencies": {
-		"@types/node": "^25.2.1",
-		"@types/micromatch": "^4.0.8",
+		"@types/node": "^25.5.0",
+		"@types/micromatch": "^4.0.10",
 		"ava": "^7.0.0",
-		"dedent": "^1.7.1",
+		"dedent": "^1.7.2",
 		"eslint-plugin-vue": "^10.8.0",
 		"execa": "^9.6.1",
 		"husky": "^9.1.7",

tsconfig.json

@@ -2,6 +2,12 @@
 	"extends": "@sindresorhus/tsconfig",
 	"compilerOptions": {
 		"outDir": "dist",
+		"lib": [
+			"DOM",
+			"DOM.Iterable",
+			"ES2023",
+			"ES2025.Iterator"
+		],
 		"resolveJsonModule": true,
 		"sourceMap": true
 	},