Update to eslint v9

.eslintignore

@@ -1,4 +0,0 @@
-dist
-node_modules
-.github
-types.generated.d.ts

.eslintrc.js

@@ -1,53 +0,0 @@
-/** @type {import("eslint").Linter.Config} */
-module.exports = {
-  env: {
-    node: true,
-    es2022: true,
-    browser: true,
-  },
-  extends: ['eslint:recommended', 'plugin:astro/recommended'],
-  parser: '@typescript-eslint/parser',
-  parserOptions: {
-    tsconfigRootDir: __dirname,
-    ecmaVersion: 'latest',
-    sourceType: 'module',
-  },
-  rules: {},
-  overrides: [
-    {
-      files: ['*.js'],
-      rules: {
-        'no-mixed-spaces-and-tabs': ['error', 'smart-tabs'],
-      },
-    },
-    {
-      files: ['*.astro'],
-      parser: 'astro-eslint-parser',
-      parserOptions: {
-        parser: '@typescript-eslint/parser',
-        extraFileExtensions: ['.astro'],
-      },
-      rules: {
-        'no-mixed-spaces-and-tabs': ['error', 'smart-tabs'],
-      },
-    },
-    {
-      files: ['*.ts'],
-      parser: '@typescript-eslint/parser',
-      extends: ['plugin:@typescript-eslint/recommended'],
-      rules: {
-        '@typescript-eslint/no-unused-vars': [
-          'error',
-          { argsIgnorePattern: '^_', destructuredArrayIgnorePattern: '^_' },
-        ],
-        '@typescript-eslint/no-non-null-assertion': 'off',
-      },
-    },
-    {
-      // Define the configuration for `<script>` tag.
-      // Script in `<script>` is assigned a virtual file name with the `.js` extension.
-      files: ['**/*.astro/*.js', '*.astro/*.js'],
-      parser: '@typescript-eslint/parser',
-    },
-  ],
-};

eslint.config.js

@@ -0,0 +1,58 @@
+import astroEslintParser from 'astro-eslint-parser';
+import eslintPluginAstro from 'eslint-plugin-astro';
+import globals from 'globals';
+import js from '@eslint/js';
+import tseslint from 'typescript-eslint';
+import typescriptParser from '@typescript-eslint/parser';
+
+export default [
+  js.configs.recommended,
+  ...eslintPluginAstro.configs['flat/recommended'],
+  ...tseslint.configs.recommended,
+  {
+    languageOptions: {
+      globals: {
+        ...globals.browser,
+      },
+    },
+  },
+  {
+    files: ['**/*.astro'],
+    languageOptions: {
+      parser: astroEslintParser,
+      parserOptions: {
+        parser: '@typescript-eslint/parser',
+        extraFileExtensions: ['.astro'],
+      },
+    },
+  },
+  {
+    files: ['**/*.{js,jsx,astro}'],
+    rules: {
+      'no-mixed-spaces-and-tabs': ['error', 'smart-tabs'],
+    },
+  },
+  {
+    // Define the configuration for `<script>` tag.
+    // Script in `<script>` is assigned a virtual file name with the `.js` extension.
+    files: ['**/*.{ts,tsx}', '**/*.astro/*.js'],
+    languageOptions: {
+      parser: typescriptParser,
+    },
+    rules: {
+      // Note: you must disable the base rule as it can report incorrect errors
+      'no-unused-vars': 'off',
+      '@typescript-eslint/no-unused-vars': [
+        'error',
+        {
+          argsIgnorePattern: '^_',
+          destructuredArrayIgnorePattern: '^_',
+        },
+      ],
+      '@typescript-eslint/no-non-null-assertion': 'off',
+    },
+  },
+  {
+    ignores: ['dist', 'node_modules', '.github', 'types.generated.d.ts'],
+  },
+];

package.json

@@ -14,7 +14,7 @@
     "preview": "astro preview",
     "astro": "astro",
     "format": "prettier -w .",
-    "lint:eslint": "eslint . --ext .js,.ts,.astro"
+    "lint:eslint": "eslint ."
   },
   "dependencies": {
     "@astrojs/rss": "^4.0.5",
@@ -42,9 +42,10 @@
     "@typescript-eslint/eslint-plugin": "^7.6.0",
     "@typescript-eslint/parser": "^7.6.0",
     "astro-eslint-parser": "^0.17.0",
-    "eslint": "^8.57.0",
+    "eslint": "^9.0.0",
     "eslint-plugin-astro": "^0.34.0",
     "eslint-plugin-jsx-a11y": "^6.8.0",
+    "globals": "^15.0.0",
     "js-yaml": "^4.1.0",
     "mdast-util-to-string": "^4.0.0",
     "prettier": "^3.2.5",