Migrate to eslint 9

eslint.config.mjs

@@ -0,0 +1,19 @@
+import eslint from '@eslint/js';
+import vue from 'eslint-plugin-vue';
+import recommended from './recommended.mjs';
+import tseslint from "typescript-eslint";
+import globals from "globals"
+
+export default tseslint.config(...vue.configs["flat/essential"], eslint.configs.recommended, ...recommended, {
+ languageOptions: {
+ globals: globals.browser,
+ }
+}, {
+ files: ['test/**.spec.js'],
+ languageOptions: {
+ globals: globals.jest,
+ },
+ rules: {
+ '@typescript-eslint/no-var-requires': 'off'
+ }
+});

index.mjs

@@ -0,0 +1,33 @@
+import tseslint from "typescript-eslint";
+
+export default tseslint.config(tseslint.configs.eslintRecommended, {
+ plugins: {
+ '@typescript-eslint': tseslint.plugin,
+ },
+ languageOptions: {
+ parserOptions: {
+ parser: {
+ 'ts': tseslint.parser,
+ 'tsx': tseslint.parser,
+ 'cts': tseslint.parser,
+ 'mts': tseslint.parser,
+ },
+ extraFileExtensions: ['.vue'],
+ ecmaFeatures: {
+ jsx: true,
+ }
+ }
+ },
+
+}, {
+ files: ['*.ts', '*.cts', '*.mts', '*.tsx', '*.vue'],
+ rules: {
+ // The core 'no-unused-vars' rules (in the eslint:recommeded ruleset)
+ // does not work with type definitions
+ 'no-unused-vars': 'off',
+ // TS already checks for that, and Typescript-Eslint recommends to disable it
+ // https://typescript-eslint.io/linting/troubleshooting#i-get-errors-from-the-no-undef-rule-about-global-variables-not-being-defined-even-though-there-are-no-typescript-errors
+ 'no-undef': 'off',
+ '@typescript-eslint/no-unused-vars': 'warn'
+ }
+});

package.json

@@ -2,10 +2,10 @@
  "name": "@vue/eslint-config-typescript",
  "version": "13.0.0",
  "description": "eslint-config-typescript for vue-cli",
- "main": "index.js",
+ "main": "index.mjs",
  "files": [
- "index.js",
- "recommended.js"
+ "index.mjs",
+ "recommended.mjs"
  ],
  "scripts": {
  "test": "jest"
@@ -30,7 +30,7 @@
  },
  "homepage": "https://github.com/vuejs/eslint-config-typescript#readme",
  "devDependencies": {
- "eslint": "^8.56.0",
+ "eslint": "^9.8.0",
  "eslint-plugin-vue": "^9.22.0",
  "execa": "^4.1.0",
  "jest": "^26.6.3",
@@ -40,7 +40,7 @@
  "vue-property-decorator": "^9.1.2"
  },
  "peerDependencies": {
- "eslint": "^8.56.0",
+ "eslint": "^9.8.0",
  "eslint-plugin-vue": "^9.0.0",
  "typescript": ">=4.7.4"
  },
@@ -50,8 +50,8 @@
  }
  },
  "dependencies": {
- "@typescript-eslint/eslint-plugin": "^7.1.1",
- "@typescript-eslint/parser": "^7.1.1",
+ "@eslint/js": "^9.8.0",
+ "typescript-eslint": "^8.0.1",
  "vue-eslint-parser": "^9.3.1"
  },
  "engines": {

recommended.mjs

@@ -0,0 +1,42 @@
+import tseslint from "typescript-eslint";
+import index from "./index.mjs";
+import eslintParser from 'vue-eslint-parser';
+
+export default tseslint.config(...index, ...tseslint.configs.recommended, {
+ languageOptions: {
+ parser: eslintParser,
+ },
+ rules: {
+ // this rule, if on, would require explicit return type on the `render` function
+ '@typescript-eslint/explicit-function-return-type': 'off',
+
+ // The following rules are enabled in an `overrides` field in the
+ // `@typescript-eslint/recommended` ruleset, only turned on for TypeScript source modules
+ // <https://github.com/typescript-eslint/typescript-eslint/blob/cb2d44650d27d8b917e8ce19423245b834db29d2/packages/eslint-plugin/src/configs/eslint-recommended.ts#L27-L30>
+
+ // But as ESLint cannot precisely target `<script lang="ts">` blocks and skip normal `<script>`s,
+ // no TypeScript code in `.vue` files would be checked against these rules.
+
+ // So we now enable them globally.
+ // That would also check plain JavaScript files, which diverges a little from
+ // the original intention of the `@typescript-eslint/recommended` rulset.
+ // But it should be mostly fine.
+ 'no-var': 'error', // ts transpiles let/const to var, so no need for vars any more
+ 'prefer-const': 'error', // ts provides better types with const
+ 'prefer-rest-params': 'error', // ts provides better types with rest args over arguments
+ 'prefer-spread': 'error', // ts transpiles spread to apply, so no need for manual apply
+ },
+}, {
+ files: ['shims-tsx.d.ts'],
+ rules: {
+ '@typescript-eslint/no-empty-interface': 'off',
+ '@typescript-eslint/no-explicit-any': 'off',
+ '@typescript-eslint/no-unused-vars': 'off'
+ }
+}, {
+ files: ['*.js', '*.cjs'],
+ rules: {
+ // in plain CommonJS modules, you can't use `import foo = require('foo')` to pass this rule, so it has to be disabled
+ '@typescript-eslint/no-var-requires': 'off'
+ }
+});

test/fixtures/default/src/shims-tsx.d.ts

@@ -3,10 +3,13 @@ import Vue, { VNode } from 'vue'
 declare global {
  namespace JSX {
  // tslint:disable no-empty-interface
+ // eslint-disable-next-line @typescript-eslint/no-empty-object-type
  interface Element extends VNode {}
  // tslint:disable no-empty-interface
+ // eslint-disable-next-line @typescript-eslint/no-empty-object-type
  interface ElementClass extends Vue {}
  interface IntrinsicElements {
+ // eslint-disable-next-line @typescript-eslint/no-explicit-any
  [elem: string]: any;
  }
  }

test/index.spec.js

@@ -11,8 +11,6 @@ async function lintProject (name) {
  eslintPath,
  [
  `${projectPath}/`,
- '--ext',
- '.vue,.js,.jsx,.cjs,.mjs,.ts,.tsx,.cts,.mts',
  '--no-ignore'
  ],
  {