chore(eslint): migrate to eslint 9

https://eslint.org/docs/latest/use/configure/migration-guide

.github/dependabot.yml

@@ -13,6 +13,9 @@ updates:
       commitlint:
         patterns:
           - '@commitlint/*'
+      eslint:
+        patterns:
+          - '@eslint/*'
       prettier:
         patterns:
           - prettier

eslint.config.mjs

@@ -0,0 +1,50 @@
+import path from 'node:path';
+import { fileURLToPath } from 'node:url';
+
+import { includeIgnoreFile } 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 prettier from 'eslint-plugin-prettier';
+import simpleImportSort from 'eslint-plugin-simple-import-sort';
+
+const __filename = fileURLToPath(import.meta.url);
+const __dirname = path.dirname(__filename);
+const gitignorePath = path.resolve(__dirname, '.gitignore');
+
+const compat = new FlatCompat({
+  baseDirectory: __dirname,
+  recommendedConfig: js.configs.recommended,
+  allConfig: js.configs.all,
+});
+
+export default [
+  includeIgnoreFile(gitignorePath),
+
+  ...compat.extends(
+    'eslint:recommended',
+    'plugin:@typescript-eslint/recommended',
+  ),
+
+  {
+    plugins: {
+      '@typescript-eslint': typescriptEslint,
+      prettier,
+      'simple-import-sort': simpleImportSort,
+    },
+
+    languageOptions: {
+      parser: tsParser,
+    },
+
+    rules: {
+      '@typescript-eslint/no-non-null-assertion': 'off',
+      'no-console': 'error',
+      'no-debugger': 'error',
+      'prettier/prettier': 'error',
+      'simple-import-sort/exports': 'error',
+      'simple-import-sort/imports': 'error',
+    },
+  },
+];

package.json

@@ -7,7 +7,7 @@
     "build": "npm run clean && vite build",
     "bundle": "scripts/bundle.sh",
     "clean": "rm -rf dist",
-    "lint": "eslint --ignore-path .gitignore .",
+    "lint": "eslint .",
     "lint:fix": "npm run lint -- --fix",
     "lint:tsc": "tsc --noEmit",
     "prepare": "husky",
@@ -22,6 +22,9 @@
   "devDependencies": {
     "@commitlint/cli": "19.4.0",
     "@commitlint/config-conventional": "19.2.2",
+    "@eslint/compat": "1.1.1",
+    "@eslint/eslintrc": "3.1.0",
+    "@eslint/js": "9.9.0",
     "@types/gtag.js": "0.0.20",
     "@typescript-eslint/eslint-plugin": "8.1.0",
     "@typescript-eslint/parser": "8.1.0",