eslint.config.mjs

import tsParser from '@typescript-eslint/parser';
import path from 'node:path';
import { fileURLToPath } from 'node:url';
import js from '@eslint/js';
import { FlatCompat } from '@eslint/eslintrc';
import prettier from 'eslint-config-prettier';

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 [
  {
    ignores: ['**/dist'],
  },
  ...compat.extends(
    'eslint:recommended',
    'plugin:@typescript-eslint/eslint-recommended',
    'plugin:@typescript-eslint/recommended'
  ),
  {
    languageOptions: {
      parser: tsParser,
      ecmaVersion: 2018,
      sourceType: 'module',
    },

    rules: {
      quotes: ['warn', 'single'],

      indent: [
        'warn',
        2,
        {
          SwitchCase: 1,
        },
      ],

      semi: ['off'],
      'comma-dangle': ['warn', 'only-multiline'],
      'dot-notation': 'off',
      eqeqeq: 'warn',
      curly: ['warn', 'all'],
      'brace-style': ['warn'],
      'prefer-arrow-callback': ['warn'],
      'max-len': ['warn', 140],
      'no-console': ['warn'],
      'no-non-null-assertion': ['off'],
      'comma-spacing': ['error'],

      'no-multi-spaces': [
        'warn',
        {
          ignoreEOLComments: true,
        },
      ],

      'no-trailing-spaces': ['warn'],

      'lines-between-class-members': [
        'warn',
        'always',
        {
          exceptAfterSingleLine: true,
        },
      ],

      '@typescript-eslint/explicit-function-return-type': 'off',
      '@typescript-eslint/no-non-null-assertion': 'off',
      '@typescript-eslint/explicit-module-boundary-types': 'off',
    },
  },
  // Last so it wins: turns off the stylistic rules above that fight prettier
  // (indent, quotes, max-len). Prettier owns formatting, eslint owns
  // correctness. Rules like eqeqeq and curly are untouched.
  prettier,
];