Jest: react-test-renderer does not work with ref methods

[mildrenben]

Do you want to request a _feature_ or report a _bug_?
Report a bug

What is the current behavior?
Ref methods cause an error to be thrown

If the current behavior is a bug, please provide the steps to reproduce and
either a repl.it demo through https://repl.it/languages/jest or a minimal
repository on GitHub that we can yarn install and yarn test.

import React from 'react'
import renderer from 'react-test-renderer'

it('Test refs', () => {
  class Comp extends React.Component {
    componentDidMount () {
      console.log(this.myRef)
      this.myRef.addEventListener('click', () => console.log('click'))
    }
    render () {
      return (
        <div ref={div => { this.myRef = div }}>foo</div>
      )
    }
  }

  const tree = renderer.create(
    <Comp />
  ).toJSON()

  expect(tree).toMatchSnapshot()
})

Cannot read property 'addEventListener' of null

What is the expected behavior?

For refs to work and have usable mock methods. I did some digging through other issues and it looks like this was fixed here https://github.com/facebook/react/issues/7740 but I'm not sure if ref DOM methods were ever fixed.

Please provide your exact Jest configuration and mention your Jest, node,
yarn/npm version and operating system.

MacOS
react-test-renderer @ 16.2.0
jest @ 21.2.1
react @ 16.1.1
node @ 8.2.1
yarn @ 0.27.5

[thymikee]

Do you have a repro of that? Does Cannot read property 'addEventListener' of null comes from Jest or react-test-renderer? I'd assume the latter, but who knows without a repo and full error message 🤷‍♂️

[mildrenben]

@thymikee Here is a repo https://github.com/mildrenben/jest-ref-issue

I believe it's being thrown by react-test-renderer

[SimenB]

You've linked to the correct issue in react's tracker - react-test-renderer does not support ref. You can either use ReactDOM or enzyme to do a real render.

[SimenB]

Also see React docs about createNodeMock: https://reactjs.org/docs/test-renderer.html#ideas for an alternative.

Either way, this is not a jest issue

[mildrenben]

createNodeMock seems perfect, thanks!