commons/client/src/index.test.tsx

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()
    })
})