Sebastian Markbåge
5d49b2b7f4
Stacked on #34481. We currently track the suspended state temporarily with a global which is safe as long as we always read it during a sync pass. However, we sometimes read it in closures and then we have to be carefully to pass the right one since it's possible another commit on a different root has started at that point. This avoids this footgun. Another reason to do this is that I want to read it in `startViewTransition` which is in an async gap after which point it's no longer safe. So I have to pass that through the `commitRoot` bound function.
react-test-renderer (DEPRECATED)
Deprecation notice
react-test-renderer is deprecated and no longer maintained. It will be removed in a future version. As of React 19, you will see a console warning when invoking ReactTestRenderer.create().
React Testing
This library creates a contrived environment and its APIs encourage introspection on React's internals, which may change without notice causing broken tests. It is instead recommended to use browser-based environments such as jsdom and standard DOM APIs for your assertions.
The React team recommends @testing-library/react as a modern alternative that uses standard APIs, avoids internals, and promotes best practices.
React Native Testing
The React team recommends @testing-library/react-native as a replacement for react-test-renderer for native integration tests. This React Native testing-library variant follows the same API design as described above and promotes better testing patterns.
Documentation
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://jestjs.io/blog/2016/07/27/jest-14.html.