Update to flatConfig and eslint v9

frontend/.prettierrc

@@ -1,5 +1,4 @@
 {
-  "semi": false,
   "singleQuote": true,
   "tabWidth": 2,
   "trailingComma": "all",

frontend/eslint.config.mjs

@@ -0,0 +1,157 @@
+import path from 'node:path';
+import { fileURLToPath } from 'node:url';
+
+import { fixupConfigRules, fixupPluginRules } from '@eslint/compat';
+import { FlatCompat } from '@eslint/eslintrc';
+import js from '@eslint/js';
+import typescriptEslint from '@typescript-eslint/eslint-plugin';
+import tsParser from '@typescript-eslint/parser';
+import react from 'eslint-plugin-react';
+import reactHooks from 'eslint-plugin-react-hooks';
+import tailwind from 'eslint-plugin-tailwindcss';
+import tseslint from 'typescript-eslint';
+
+const __filename = fileURLToPath(import.meta.url);
+const __dirname = path.dirname(__filename);
+const compat = new FlatCompat({
+  baseDirectory: __dirname,
+  recommendedConfig: js.configs.recommended,
+  allConfig: js.configs.all,
+});
+
+export default [
+  ...tseslint.config({
+    languageOptions: {
+      parserOptions: {
+        projectService: true,
+        tsconfigRootDir: import.meta.dirname,
+      },
+    },
+  }),
+  js.configs.recommended,
+  ...tailwind.configs['flat/recommended'],
+  ...fixupConfigRules(
+    compat.extends(
+      'eslint:recommended',
+      'plugin:react/recommended',
+      'plugin:react-hooks/recommended',
+      'plugin:prettier/recommended',
+      'next',
+    ),
+  ),
+  {
+    plugins: {
+      '@typescript-eslint': fixupPluginRules(typescriptEslint),
+      react: fixupPluginRules(react),
+      'react-hooks': fixupPluginRules(reactHooks),
+    },
+
+    languageOptions: {
+      parser: tsParser,
+      ecmaVersion: 2020,
+      sourceType: 'module',
+
+      parserOptions: {
+        ecmaFeatures: {
+          jsx: true,
+        },
+      },
+    },
+    settings: {
+      react: {
+        version: 'detect',
+      },
+      'import/resolver': {
+        typescript: {
+          alwaysTryTypes: true,
+        },
+      },
+    },
+    rules: {
+      'import/named': 'error',
+      'import/namespace': 'error',
+      'import/default': 'error',
+      'import/export': 'error',
+      'prefer-const': 'warn',
+      eqeqeq: 'error',
+      'no-var': 'warn',
+      'no-unused-vars': 'warn',
+      'no-duplicate-imports': 'error',
+      'object-shorthand': 'warn',
+      'quote-props': ['warn', 'as-needed'],
+      'react/prop-types': 'off',
+      '@typescript-eslint/explicit-module-boundary-types': 'off',
+      '@typescript-eslint/consistent-type-exports': 'error',
+      '@typescript-eslint/consistent-type-imports': [
+        'error',
+        {
+          disallowTypeAnnotations: false,
+          fixStyle: 'separate-type-imports',
+          prefer: 'type-imports',
+        },
+      ],
+      '@typescript-eslint/no-explicit-any': 'error',
+      '@typescript-eslint/no-import-type-side-effects': 'error',
+      // 'no-restricted-imports': [
+      //   'warn',
+      //   {
+      //     patterns: [
+      //       {
+      //         group: ['@/*'],
+      //         message: "Avoid using '@/'. Use '@' instead.",
+      //       },
+      //     ],
+      //   },
+      // ],
+      'sort-imports': [
+        'warn',
+        {
+          ignoreCase: true,
+          ignoreDeclarationSort: true,
+          ignoreMemberSort: false,
+          memberSyntaxSortOrder: ['none', 'all', 'multiple', 'single'],
+          allowSeparatedGroups: false,
+        },
+      ],
+      'import/order': [
+        'warn',
+        {
+          groups: [
+            'builtin',
+            'external',
+            'internal',
+            'parent',
+            'sibling',
+            'index',
+            'object',
+            'type',
+          ],
+          pathGroups: [
+            {
+              pattern: 'react',
+              group: 'external',
+              position: 'before',
+            },
+            {
+              pattern: '@**',
+              group: 'internal',
+              position: 'before',
+            },
+          ],
+          pathGroupsExcludedImportTypes: ['react'],
+          'newlines-between': 'always',
+          alphabetize: {
+            order: 'asc',
+            caseInsensitive: true,
+          },
+        },
+      ],
+      'react-hooks/rules-of-hooks': 'error',
+      'react-hooks/exhaustive-deps': 'warn',
+      'react/react-in-jsx-scope': 'off',
+      'tailwindcss/no-custom-classname': 'warn',
+      'tailwindcss/classnames-order': 'warn',
+      'prettier/prettier': 'warn',
+    },
+  },
+];