eslint.config.mjs

import eslintPluginTs from '@typescript-eslint/eslint-plugin';
import parserTs from '@typescript-eslint/parser';

export default [
  {
    files: ['**/*.ts'],
    languageOptions: {
      parser: parserTs,
      parserOptions: {
        ecmaVersion: 2020,
        sourceType: 'module',
        project: './tsconfig.json',
        tsconfigRootDir: process.cwd(),
      },
    },
    plugins: {
      '@typescript-eslint': eslintPluginTs,
    },
    rules: {
      // --- Recommended ---
      ...eslintPluginTs.configs.recommended.rules,

      // --- Safety ---
      'no-implicit-coercion': 'error',
      'eqeqeq': ['error', 'always'],
      'curly': 'error',
      'no-fallthrough': 'error',
      'default-case': 'error',

      // --- Style ---
      'quotes': ['error', 'single', { avoidEscape: true }],
      'comma-dangle': ['error', 'always-multiline'],
      'no-trailing-spaces': 'error',
      'no-multi-spaces': 'error',
      'no-multiple-empty-lines': ['error', { max: 1, maxEOF: 0 }],

      // --- Clean code ---
      '@typescript-eslint/no-unnecessary-type-assertion': 'error',
      '@typescript-eslint/prefer-nullish-coalescing': 'error',
      '@typescript-eslint/prefer-optional-chain': 'error',

      // --- Customization ---
      '@typescript-eslint/consistent-type-imports': 'error',
      '@typescript-eslint/no-unused-vars': ['error', { argsIgnorePattern: '^_' }],
      '@typescript-eslint/no-explicit-any': 'error',
      '@typescript-eslint/explicit-function-return-type': 'off',

      // --- Others ---
      'no-var': 'error',
      'prefer-const': 'error',
      'no-shadow': 'error',
    },
  },
];