.eslintrc.js

// @ts-check

/** @type {import('eslint').Linter.Config} */
module.exports = {
  extends: ['eslint:recommended', 'plugin:prettier/recommended'],
  plugins: ['prettier'],
  rules: {
    'prettier/prettier': 'error',
    'no-use-before-define': 'off',
    'no-prototype-builtins': 'off',
  },
  env: {
    es2017: true,
    node: true,
  },
  parserOptions: { sourceType: 'module', ecmaVersion: 2018 },
  overrides: [
    {
      files: ['src/**/*.ts'],
      parser: '@typescript-eslint/parser',
      parserOptions: { project: './tsconfig.json' },
      plugins: ['@typescript-eslint'],
      extends: [
        'eslint:recommended',
        'plugin:@typescript-eslint/eslint-recommended',
        'plugin:@typescript-eslint/recommended',
        'prettier/@typescript-eslint',
      ],
      rules: {
        'no-use-before-define': 'off',
        '@typescript-eslint/no-use-before-define': 'off',
        '@typescript-eslint/explicit-function-return-type': 'off',
        '@typescript-eslint/no-explicit-any': 'off',
        '@typescript-eslint/explicit-module-boundary-types': 'off',
        '@typescript-eslint/no-unused-vars': 'off',
        '@typescript-eslint/ban-types': 'off',
        'no-prototype-builtins': 'off',
      },
    },
    {
      files: ['src/**/__tests__/*.spec.ts'],
      parserOptions: { project: './tsconfig.jest.json' },
      env: {
        jest: true,
      },
    },
  ],
};