.eslintrc.js

const DOMGlobals = [ 'window', 'document' ]

module.exports = {
  parser: '@typescript-eslint/parser',
  parserOptions: {
    sourceType: 'module'
  },
  rules: {
    'no-unused-vars': [
      'error',
      // we are only using this rule to check for unused arguments since TS
      // catches unused variables but not args.
      { varsIgnorePattern: '.*', args: 'after-used', argsIgnorePattern: '^_' }
    ],
    // most of the codebase are expected to be env agnostic
    'no-restricted-globals': [ 'error', ...DOMGlobals ],
    // since we target ES2015 for baseline support, we need to forbid object
    // rest spread usage (both assign and destructure)
    'no-restricted-syntax': [
      'error',
      'ObjectExpression > SpreadElement',
      'ObjectPattern > RestElement'
    ]
  },
  overrides: [
    // tests, no restrictions (runs in Node / jest with jsdom)
    {
      files: [ '**/__tests__/**', 'test-dts/**' ],
      rules: {
        'no-restricted-globals': 'off',
        'no-restricted-syntax': 'off'
      }
    }
  ]
}