eslint.config.mjs

// @ts-check
import eslint from '@eslint/js';
import { defineConfig, globalIgnores } from 'eslint/config';
import turboConfig from 'eslint-config-turbo/flat';
import eslintPluginPrettierRecommended from 'eslint-plugin-prettier/recommended';
import simpleImportSort from 'eslint-plugin-simple-import-sort';
import eslintPluginUnicorn from 'eslint-plugin-unicorn';
import globals from 'globals';
import tseslint from 'typescript-eslint';

export default defineConfig(
  globalIgnores([
    'docs',
    'tests/generated',
    'samples',
    '.husky',
    'packages/hono/src/zValidator.ts',
    '**/.yarn',
    '**/.turbo',
    '**/dist',
  ]),
  turboConfig,
  eslint.configs.recommended,
  tseslint.configs.strictTypeChecked,
  tseslint.configs.stylisticTypeChecked,
  eslintPluginUnicorn.configs.recommended,
  {
    languageOptions: {
      globals: globals.builtin,
      parserOptions: {
        projectService: true,
        tsconfigRootDir: import.meta.dirname,
      },
    },
    rules: {
      'no-useless-escape': 'warn',
      'no-case-declarations': 'warn',
      'no-prototype-builtins': 'warn',
      'unicorn/prevent-abbreviations': 'off',
      'unicorn/consistent-function-scoping': [
        'error',
        { checkArrowFunctions: false },
      ],
      '@typescript-eslint/restrict-template-expressions': [
        'error',
        // default (not strict) settings
        // consider tightening these in the future
        {
          allow: [{ name: ['Error', 'URL', 'URLSearchParams'], from: 'lib' }],
          allowAny: true,
          allowBoolean: true,
          allowNullish: true,
          allowNumber: true,
          allowRegExp: true,
        },
      ],

      // enable these in the future
      'unicorn/no-null': 'warn',
      'unicorn/prefer-at': 'off',
      'unicorn/no-array-reduce': 'warn',
      '@typescript-eslint/no-unused-vars': 'warn',
      '@typescript-eslint/ban-ts-comment': 'warn',
      '@typescript-eslint/no-explicit-any': 'warn',
      '@typescript-eslint/no-require-imports': 'warn',
      '@typescript-eslint/no-unsafe-assignment': 'warn',
      '@typescript-eslint/no-unsafe-function-type': 'warn',
      '@typescript-eslint/consistent-type-definitions': 'off',
      '@typescript-eslint/no-unnecessary-type-assertion': 'off',
      '@typescript-eslint/no-non-null-asserted-optional-chain': 'warn',
    },
  },
  {
    plugins: {
      'simple-import-sort': simpleImportSort,
    },
    rules: {
      'simple-import-sort/imports': 'error',
      'simple-import-sort/exports': 'error',
    },
  },
  {
    files: ['**/*.{js,mjs,cjs}'],
    extends: [tseslint.configs.disableTypeChecked],
  },
  eslintPluginPrettierRecommended, // also sets up eslint-config-prettier
);