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Sebastian Markbåge
a0a435d68f
This refactors key warning to happen inline after we've matched a Fiber. I didn't want to do that originally because it was riskier. But it turns out to be straightforward enough. This lets us use that Fiber as the source of the warning which matters to DevTools because then DevTools can associate it with the right component after it mounts. We can also associate the duplicate key warning with this Fiber. That way we'll get the callsite with the duplicate key on the stack and can associate this warning with the child that had the duplicate. I kept the forked DevTools tests because the warning now is counted on the Child instead of the Parent (18 behavior). However, this won't be released in 19.0.0 so I only test this in whatever the next version is. Doesn't seem worth it to have a test for just the 19.0.0 behavior.
react
React is a JavaScript library for creating user interfaces.
The react package contains only the functionality necessary to define React components. It is typically used together with a React renderer like react-dom for the web, or react-native for the native environments.
Note: by default, React will be in development mode. The development version includes extra warnings about common mistakes, whereas the production version includes extra performance optimizations and strips all error messages. Don't forget to use the production build when deploying your application.
Usage
import { useState } from 'react';
import { createRoot } from 'react-dom/client';
function Counter() {
const [count, setCount] = useState(0);
return (
<>
<h1>{count}</h1>
<button onClick={() => setCount(count + 1)}>
Increment
</button>
</>
);
}
const root = createRoot(document.getElementById('root'));
root.render(<Counter />);