mirror of
https://github.com/facebook/react.git
synced 2026-02-27 03:07:57 +00:00
a0733fe13d
* pure A higher-order component version of the `React.PureComponent` class. During an update, the previous props are compared to the new props. If they are the same, React will skip rendering the component and its children. Unlike userspace implementations, `pure` will not add an additional fiber to the tree. The first argument must be a functional component; it does not work with classes. `pure` uses shallow comparison by default, like `React.PureComponent`. A custom comparison can be passed as the second argument. Co-authored-by: Andrew Clark <acdlite@fb.com> Co-authored-by: Sophie Alpert <sophiebits@fb.com> * Warn if first argument is not a functional component
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.