“ReferenceError: document is not defined” when trying to test a create-react-app project

For me either of these worked

In package.json file adding test script env flag

"scripts": {
   "test": "react-scripts test --env=jsdom"
}

Using enzyme

 import { shallow } from 'enzyme';

 it('renders without crashing', () => {
  shallow(<App />);
 });