From 3628fd1e84254ca65f6bad07a330ac4a1ab8f82c Mon Sep 17 00:00:00 2001
From: Anthony Rey <gnuk@mailoo.org>
Date: Thu, 8 Aug 2024 10:36:42 +0200
Subject: [PATCH] Migrate to eslint 9

---
 .eslintrc.js                             | 21 -----------
 eslint.config.mjs                        | 19 ++++++++++
 index.js                                 | 46 -----------------------
 index.mjs                                | 33 ++++++++++++++++
 package.json                             | 14 +++----
 recommended.js                           | 48 ------------------------
 recommended.mjs                          | 42 +++++++++++++++++++++
 test/fixtures/default/src/shims-tsx.d.ts |  3 ++
 test/index.spec.js                       |  2 -
 9 files changed, 104 insertions(+), 124 deletions(-)
 delete mode 100644 .eslintrc.js
 create mode 100644 eslint.config.mjs
 delete mode 100644 index.js
 create mode 100644 index.mjs
 delete mode 100644 recommended.js
 create mode 100644 recommended.mjs

diff --git a/.eslintrc.js b/.eslintrc.js
deleted file mode 100644
index e43ef3f..0000000
--- a/.eslintrc.js
+++ /dev/null
@@ -1,21 +0,0 @@
-module.exports = {
-  root: true,
-  env: {
-    node: true
-  },
-  extends: [
-    'plugin:vue/essential',
-    'eslint:recommended',
-    require.resolve('./recommended')
-  ],
-
-  overrides: [{
-    files: ['test/**.spec.js'],
-    env: {
-      jest: true
-    },
-    rules: {
-      '@typescript-eslint/no-var-requires': 'off'
-    }
-  }]
-}
diff --git a/eslint.config.mjs b/eslint.config.mjs
new file mode 100644
index 0000000..8ed50d3
--- /dev/null
+++ b/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'
+    }
+});
\ No newline at end of file
diff --git a/index.js b/index.js
deleted file mode 100644
index 9d1ef63..0000000
--- a/index.js
+++ /dev/null
@@ -1,46 +0,0 @@
-module.exports = {
-  plugins: ['@typescript-eslint'],
-
-  // Prerequisite `eslint-plugin-vue`, being extended, sets
-  // root property `parser` to `'vue-eslint-parser'`, which, for code parsing,
-  // in turn delegates to the parser, specified in `parserOptions.parser`:
-  // https://github.com/vuejs/eslint-plugin-vue#what-is-the-use-the-latest-vue-eslint-parser-error
-  parserOptions: {
-    parser: {
-      'js': 'espree',
-      'jsx': 'espree',
-      'cjs': 'espree',
-      'mjs': 'espree',
-
-      'ts': require.resolve('@typescript-eslint/parser'),
-      'tsx': require.resolve('@typescript-eslint/parser'),
-      'cts': require.resolve('@typescript-eslint/parser'),
-      'mts': require.resolve('@typescript-eslint/parser'),
-
-      // Leave the template parser unspecified, so that it could be determined by `<script lang="...">`
-    },
-    extraFileExtensions: ['.vue'],
-    ecmaFeatures: {
-      jsx: true
-    }
-  },
-
-  extends: [
-    'plugin:@typescript-eslint/eslint-recommended'
-  ],
-
-  overrides: [
-    {
-      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'
-      }
-    }
-  ]
-}
diff --git a/index.mjs b/index.mjs
new file mode 100644
index 0000000..b99334e
--- /dev/null
+++ b/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'
+    }
+});
\ No newline at end of file
diff --git a/package.json b/package.json
index 44484ba..ffa8a59 100644
--- a/package.json
+++ b/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": {
diff --git a/recommended.js b/recommended.js
deleted file mode 100644
index 21f1423..0000000
--- a/recommended.js
+++ /dev/null
@@ -1,48 +0,0 @@
-module.exports = {
-  extends: [
-    require.resolve('./index'),
-    'plugin:@typescript-eslint/recommended'
-  ],
-  
-  // the ts-eslint recommended ruleset sets the parser so we need to set it back
-  parser: require.resolve('vue-eslint-parser'),
-
-  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
-  },
-
-  overrides: [
-    {
-      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'
-      }
-    }
-  ]
-}
diff --git a/recommended.mjs b/recommended.mjs
new file mode 100644
index 0000000..740ed93
--- /dev/null
+++ b/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'
+    }
+});
\ No newline at end of file
diff --git a/test/fixtures/default/src/shims-tsx.d.ts b/test/fixtures/default/src/shims-tsx.d.ts
index a175b0d..48edf7b 100644
--- a/test/fixtures/default/src/shims-tsx.d.ts
+++ b/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;
     }
   }
diff --git a/test/index.spec.js b/test/index.spec.js
index 8bd35fa..7792e6c 100644
--- a/test/index.spec.js
+++ b/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'
       ],
       {