vendredi 22 avril 2016

jsdom: dispatchEvent/addEventListener doesn't seem to work

Summary:

I am attempting to test a React component that listens to native DOM events in its componentWillMount.

I'm finding that jsdom (@8.4.0) doesn't work as expected when it comes to dispatching events and adding event listeners.

The simplest bit of code I can extract:

window.addEventListener('click', () => {
  throw new Error("success")
})

const event = new Event('click')
document.dispatchEvent(event)

throw new Error('failure')

This throws "failure".


Context:

At risk of the above being an XY problem, I want to provide more context.

Here is an extracted/simplified version of the component I'm trying to test. You can see it working on Webpackbin.

import React from 'react'

export default class Example extends React.Component {
  constructor() {
    super()
    this._onDocumentClick = this._onDocumentClick.bind(this)
  }

  componentWillMount() {
    this.setState({ clicked: false })
    window.addEventListener('click', this._onDocumentClick)
  }

  _onDocumentClick() {
    const clicked = this.state.clicked || false
    this.setState({ clicked: !clicked })
  }


  render() {
    return <p>{JSON.stringify(this.state.clicked)}</p>
  }
}

Here is the test I'm trying to write.

import React from 'react'
import ReactDOM from 'react-dom'
import { mount } from 'enzyme'

import Example from '../src/example'

describe('test', () => {
  it('test', () => {
    const wrapper = mount(<Example />)

    const event = new Event('click')
    document.dispatchEvent(event)

    // at this point, I expect the component to re-render,
    // with updated state.

    expect(wrapper.text()).to.match(/true/)
  })
})

Just for completeness, here is my test_helper.js which initializes jsdom:

import { jsdom } from 'jsdom'
import chai from 'chai'

const doc = jsdom('<!doctype html><html><body></body></html>')
const win = doc.defaultView

global.document = doc
global.window = win

Object.keys(window).forEach((key) => {
  if (!(key in global)) {
    global[key] = window[key]
  }
})


Reproduction case:

I have a repro case here: http://ift.tt/1XNtZrn

git clone http://ift.tt/1SBMKzH cd repro-jsdom-events-not-firing npm install npm test

Aucun commentaire:

Enregistrer un commentaire