import ReactDOM from 'react-dom' import { renderToDOM } from './index' describe('test ReactDOM.render', () => { const originalRender = ReactDOM.render const originalGetElement = global.document.getElementById beforeEach(() => { global.document.getElementById = () => true ReactDOM.render = jest.fn() }) afterAll(() => { global.document.getElementById = originalGetElement ReactDOM.render = originalRender }) it('should call ReactDOM.render', () => { renderToDOM() expect(ReactDOM.render).toHaveBeenCalled() }) })