41950d14a5
This updates the behavior of form actions to automatically reset the form's uncontrolled inputs after the action finishes. This is a frequent feature request for people using actions and it aligns the behavior of client-side form submissions more closely with MPA form submissions. It has no impact on controlled form inputs. It's the same as if you called `form.reset()` manually, except React handles the timing of when the reset happens, which is tricky/impossible to get exactly right in userspace. The reset shouldn't happen until the UI has updated with the result of the action. So, resetting inside the action is too early. Resetting in `useEffect` is better, but it's later than ideal because any effects that run before it will observe the state of the form before it's been reset. It needs to happen in the mutation phase of the transition. More specifically, after all the DOM mutations caused by the transition have been applied. That way the `defaultValue` of the inputs are updated before the values are reset. The idea is that the `defaultValue` represents the current, canonical value sent by the server. Note: this change has no effect on form submissions that aren't triggered by an action.
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react-test-renderer is deprecated and no longer maintained.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.