.eslintrc.js

// https://eslint.org/docs/user-guide/configuring

module.exports = {
  ignorePatterns: ['node_modules/', 'dist/', 'e2e'],
  extends: [
    'eslint:recommended',
    'plugin:node/recommended-script',
    'plugin:jest/recommended',
  ],
  rules: {
    'semi': ['error', 'always'],
    'indent': ['error', 2],
    'no-var': 0,
    'prefer-rest-params': 0,
    'prefer-spread': 0,
    'prefer-const': 0,
    'node/no-unpublished-require': 0,
    'node/no-unpublished-import': 0,
    'camelcase': 2,
    'complexity': [2, 7],
    'curly': 2,
    'dot-notation': 0,
    'guard-for-in': 2,
    'new-cap': [2, { 'properties': false }],
    'no-caller': 2,
    'no-empty': 2,
    'no-eval': 2,
    'no-implied-eval': 2,
    'no-multi-str': 0,
    'no-new': 2,
    'no-plusplus': 0,
    'no-undef': 2,
    'no-unused-expressions': [2, { 'allowShortCircuit': true, 'allowTernary': true }],
    'no-unused-vars': 2,
    'max-depth': [2, 3],
    'max-len': [2, 150],
    'max-params': [2, 5],
    'max-statements': [2, 25],
    'quotes': [2, 'single', { 'allowTemplateLiterals': true }],
    'strict': 0,
    'wrap-iife': [2, 'any'],
  },
  overrides: [
    {
      files: ['*.ts', '*.tsx'],
      extends: [
        'plugin:@typescript-eslint/eslint-recommended',
        'plugin:@typescript-eslint/recommended'
      ],
      parser: '@typescript-eslint/parser',
      parserOptions: {
        ecmaVersion: 2020,
        ecmaFeatures: { 'jsx': true },
        sourceType: 'module',
        project: 'types/tsconfig.json'
      },
      env: {
        es6: true,
        node: false
      },
      plugins: ['@typescript-eslint'],
      rules: {
        'node/no-unsupported-features/es-syntax': 0,
        'node/no-unsupported-features/node-builtins': 0
      }
    },
    {
      // ES6 processed by Babel
      files: [
        '*.js',
        '*.test.js'
      ],
      plugins: [
        'node',
        'jest',
      ],
      parser: '@babel/eslint-parser',
      parserOptions: {
        ecmaVersion: 2020,
        sourceType: 'module'
      },
      env: {
        es6: true,
        node: false
      },
      rules: {
        'node/no-unsupported-features/es-syntax': 0,
        'node/no-unsupported-features/node-builtins': 0
      }
    },
    {
      // Jest specs
      files: ['*.test.js'],
      plugins: [
        'node',
        'jest',
      ],
      env: {
        jest: true
      }
    }
  ]
};