feat: add eslint flat config

eslint.config.mjs

@@ -0,0 +1,50 @@
+// @ts-check
+import eslint from '@eslint/js';
+import tsPlugin from '@typescript-eslint/eslint-plugin';
+import beautifulSort from 'eslint-plugin-beautiful-sort';
+import eslintPluginPrettierRecommended from 'eslint-plugin-prettier/recommended';
+import tseslint from 'typescript-eslint';
+import globals from 'globals';
+
+export default tseslint.config(
+  eslint.configs.recommended,
+  eslintPluginPrettierRecommended,
+  ...tseslint.configs.recommended,
+  {
+    files: ['**/*.ts'],
+    ignores: ['node_modules', 'dist', 'bin'],
+    languageOptions: {
+      globals: {
+        ...globals.node,
+        ...globals.jest,
+      },
+      parserOptions: {
+        project: true,
+        tsconfigRootDir: import.meta.dirname,
+      },
+    },
+    plugins: {
+      '@typescript-eslint': tsPlugin,
+      'beautiful-sort': beautifulSort,
+    },
+    rules: {
+      'no-use-before-define': 'error',
+      'object-shorthand': 'warn',
+      'no-async-promise-executor': 'warn',
+      '@typescript-eslint/consistent-type-definitions': ['error', 'type'],
+      '@typescript-eslint/interface-name-prefix': 'off',
+      '@typescript-eslint/explicit-function-return-type': 'off',
+      '@typescript-eslint/explicit-module-boundary-types': 'off',
+      '@typescript-eslint/no-explicit-any': 'warn',
+      '@typescript-eslint/no-misused-promises': 'warn',
+      '@typescript-eslint/no-deprecated': 'error',
+      'beautiful-sort/import': [
+        'error',
+        {
+          special: [],
+          order: ['special', 'namespace', 'default', 'defaultObj', 'obj', 'none'],
+        },
+      ],
+    },
+  },
+);