Migrate ESLint 8 → 9

- Migrates to flat config
- Replaces eslint-plugin-import with eslint-plugin-import-x

eslint.config.js

@@ -0,0 +1,80 @@
+import js from '@eslint/js';
+import eslintPluginImportX from 'eslint-plugin-import-x';
+import pluginVue from 'eslint-plugin-vue';
+import { configs as tsConfigs, parser as tsParser } from 'typescript-eslint';
+import parserVue from 'vue-eslint-parser';
+
+export default [
+  js.configs.recommended,
+  eslintPluginImportX.flatConfigs.recommended,
+  eslintPluginImportX.flatConfigs.typescript,
+  ...tsConfigs.recommended,
+  ...pluginVue.configs['flat/recommended'],
+  {
+    languageOptions: {
+      parser: tsParser,
+      ecmaVersion: 2020,
+      sourceType: 'module',
+    },
+    rules: {
+      'import-x/first': 'error',
+      'import-x/exports-last': 'error',
+      'import-x/newline-after-import': 'error',
+      'import-x/prefer-default-export': 'error',
+      'import-x/group-exports': 'error',
+      'import-x/no-duplicates': 'error',
+      'import-x/no-amd': 'error',
+      'import-x/no-commonjs': 'error',
+      'import-x/order': [
+        'error',
+        {
+          groups: [
+            'builtin',
+            'external',
+            'internal',
+            'parent',
+            'sibling',
+            'index',
+          ],
+          'newlines-between': 'always',
+          alphabetize: {
+            order: 'asc',
+          },
+        },
+      ],
+      'import-x/no-unused-modules': 'error',
+      'import-x/no-mutable-exports': 'error',
+      'import-x/no-extraneous-dependencies': [
+        'error',
+        {
+          devDependencies: [
+            'eslint.config.js',
+            'vite.config.ts',
+            'test/**/*.test.ts',
+          ],
+        },
+      ],
+      '@typescript-eslint/explicit-function-return-type': 'error',
+      'vue/component-api-style': ['error', ['script-setup']],
+      'vue/custom-event-name-casing': ['error', 'kebab-case'],
+      'vue/no-empty-component-block': 'error',
+      'vue/html-self-closing': 'off',
+      'vue/singleline-html-element-content-newline': 'off',
+    },
+  },
+  {
+    files: ['*.vue', '**/*.vue'],
+    languageOptions: {
+      parser: parserVue,
+      parserOptions: {
+        parser: '@typescript-eslint/parser',
+      },
+    },
+  },
+  {
+    files: ['src/pages/**/*.vue'],
+    rules: {
+      'vue/multi-word-component-names': 'off',
+    },
+  },
+];

package.json

@@ -30,22 +30,24 @@
     "vue-router": "^4.4.3"
   },
   "devDependencies": {
-    "@typescript-eslint/eslint-plugin": "^8.4.0",
+    "@eslint/js": "^9.11.0",
     "@vitejs/plugin-vue": "^5.1.3",
     "@vue/compiler-sfc": "^3.5.3",
-    "eslint": "^8.57.0",
+    "eslint": "^9.11.0",
     "eslint-import-resolver-typescript": "^3.6.3",
-    "eslint-plugin-import": "^2.30.0",
+    "eslint-plugin-import-x": "^4.2.1",
     "eslint-plugin-vue": "^9.28.0",
     "prettier": "^3.3.3",
     "stylelint": "^16.9.0",
     "stylelint-config-property-sort-order-smacss": "^10.0.0",
     "stylelint-config-recommended-vue": "^1.5.0",
     "stylelint-config-standard": "^36.0.1",
     "typescript": "^5.5.4",
+    "typescript-eslint": "^8.6.0",
     "vite": "^5.4.3",
     "vite-plugin-vue-devtools": "^7.4.4",
     "vite-tsconfig-paths": "^5.0.1",
+    "vue-eslint-parser": "^9.4.3",
     "vue-tsc": "^2.1.6"
   }
 }