2774208039
Basically make `console.error` and `console.warn` behave like normal - when a component stack isn't appended. I need this because I need to be able to print rich logs with the component stack option and to be able to disable instrumentation completely in `console.createTask` environments that don't need it. Currently we can't print logs with richer objects because they're toString:ed first. In practice, pretty much all arguments we log are already toString:ed so it's not necessary anyway. Some might be like a number. So it would only be a problem if some environment can't handle proper consoles but then it's up to that environment to toString it before logging. The `Warning: ` prefix is historic and is both noisy and confusing. It's mostly unnecessary since the UI surrounding `console.error` and `console.warn` tend to have visual treatment around it anyway. However, it's actively misleading when `console.error` gets prefixed with a Warning that we consider an error level. There's an argument to be made that some of our `console.error` don't make the bar for an error but then the argument is to downgrade each of those to `console.warn` - not to brand all our actual error logging with `Warning: `. Apparently something needs to change in React Native before landing this because it depends on the prefix somehow which probably doesn't make sense already.
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react-test-renderer is deprecated and no longer maintained.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.