Edit

Modals

import React, { useEffect } from 'react'
import ReactDOM from 'react-dom'
import { render, fireEvent } from '@testing-library/react'

const modalRoot = document.createElement('div')
modalRoot.setAttribute('id', 'modal-root')
document.body.appendChild(modalRoot)

const Modal = ({ onClose, children }) => {
  const el = document.createElement('div')

  useEffect(() => {
    modalRoot.appendChild(el)

    return () => modalRoot.removeChild(el)
  })

  return ReactDOM.createPortal(
    <div onClick={onClose}>
      <div onClick={e => e.stopPropagation()}>
        {children}
        <hr />
        <button onClick={onClose}>Close</button>
      </div>
    </div>,
    el
  )
}

test('modal shows the children and a close button', () => {
  // Arrange
  const handleClose = jest.fn()

  // Act
  const { getByText } = render(
    <Modal onClose={handleClose}>
      <div>test</div>
    </Modal>
  )
  // Assert
  expect(getByText('test')).toBeTruthy()

  // Act
  fireEvent.click(getByText(/close/i))

  // Assert
  expect(handleClose).toHaveBeenCalledTimes(1)
})