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Dan Abramov
342fa78ed4
* Throw away old shallow renderer state on type change This worked in function components but was broken for classes. It incorrectly retained the old instance even if the type was different. * Remove _previousComponentIdentity We only needed this because we didn't correctly reset based on type. Now we do so this can go away. * Use _reset when unmounting * Use arbitrary componentIdentity There was no particular reason it was set to element.type. We just wanted to check if something is a render phase update. * Support Hook state updates in shallow renderer
react-test-renderer
This package provides an experimental React renderer that can be used to render React components to pure JavaScript objects, without depending on the DOM or a native mobile environment.
Essentially, this package makes it easy to grab a snapshot of the "DOM tree" rendered by a React DOM or React Native component without using a browser or jsdom.
Documentation:
https://reactjs.org/docs/test-renderer.html
Usage:
const ReactTestRenderer = require('react-test-renderer');
const renderer = ReactTestRenderer.create(
<Link page="https://www.facebook.com/">Facebook</Link>
);
console.log(renderer.toJSON());
// { type: 'a',
// props: { href: 'https://www.facebook.com/' },
// children: [ 'Facebook' ] }
You can also use Jest's snapshot testing feature to automatically save a copy of the JSON tree to a file and check in your tests that it hasn't changed: https://facebook.github.io/jest/blog/2016/07/27/jest-14.html.