142cfde89e
## Summary `FragmentInstance.addEventListener` and `removeEventListener` fail to cross-match listeners when the `capture` option is passed as a **boolean** in one call and an **options object** in the other. This violates the [DOM Living Standard](https://dom.spec.whatwg.org/#dom-eventtarget-removeeventlistener), which states that `addEventListener(type, fn, true)` and `addEventListener(type, fn, {capture: true})` are identical. ### Root Cause In `ReactFiberConfigDOM.js`, the `normalizeListenerOptions` function generates a listener key string for deduplication. The boolean branch generates a **different format** than the object branch: ```js // Boolean branch (old) — produces "c=1" return `c=${opts ? '1' : '0'}`; // Object branch — produces "c=1&o=0&p=0" return `c=${opts.capture ? '1' : '0'}&o=${opts.once ? '1' : '0'}&p=${opts.passive ? '1' : '0'}`; ``` Because the keys differ, `indexOfEventListener` cannot match them — so `removeEventListener('click', fn, {capture: true})` silently fails to remove a listener registered with `addEventListener('click', fn, true)`, and vice versa. This causes a **memory leak and event listener accumulation** on all Fragment child DOM nodes. ### Fix Normalize the boolean branch to produce the same full key format: ```js // Boolean branch (fixed) — now produces "c=1&o=0&p=0" (matches object branch) return `c=${opts ? '1' : '0'}&o=0&p=0`; ``` This makes both forms produce an identical key, matching the DOM spec behavior. ### When Was This Introduced This bug has been present since `FragmentInstance` event listener tracking was first added. It became reachable in production as of [#36026](https://github.com/facebook/react/pull/36026) which enabled `enableFragmentRefs` + `enableFragmentRefsInstanceHandles` across all builds (merged 3 days ago). ### Tests Added two new regression tests to `ReactDOMFragmentRefs-test.js`: 1. `removes a capture listener registered with boolean when removed with options object` 2. `removes a capture listener registered with options object when removed with boolean` Both tests were failing before this fix and pass after. ## How did you test this change? Added two new automated tests covering both cross-form removal directions. Existing tests continue to pass. ## Changelog ### React DOM - **Fixed** `FragmentInstance.removeEventListener()` not removing capture-phase listeners when the `capture` option form (boolean vs options object) differs between `add` and `remove` calls.
react-dom
This package serves as the entry point to the DOM and server renderers for React. It is intended to be paired with the generic React package, which is shipped as react to npm.
Installation
npm install react react-dom
Usage
In the browser
import { createRoot } from 'react-dom/client';
function App() {
return <div>Hello World</div>;
}
const root = createRoot(document.getElementById('root'));
root.render(<App />);
On the server
import { renderToPipeableStream } from 'react-dom/server';
function App() {
return <div>Hello World</div>;
}
function handleRequest(res) {
// ... in your server handler ...
const stream = renderToPipeableStream(<App />, {
onShellReady() {
res.statusCode = 200;
res.setHeader('Content-type', 'text/html');
stream.pipe(res);
},
// ...
});
}
API
react-dom
See https://react.dev/reference/react-dom
react-dom/client
See https://react.dev/reference/react-dom/client