@samitouri / QOS-React / commits / aad7c664ff

[Flight] Don't try to close debug channel twice (#34340)

When the debug channel was already closed, we must not try to close it again when the Response gets garbage collected. **Test plan:** 1. reduce the Flight fixture `App` component to a minimum [^1] - remove everything from `<body>` - delete the `console.log` statement 2. open the app in Firefox (seems to have a more aggressive GC strategy) 3. wait a few seconds On `main`, you will see the following error in the browser console: ``` TypeError: Can not close stream after closing or error ``` With this change, the error is gone. [^1]: It's a bit concerning that step 1 is needed to reproduce the issue. Either GC is behaving differently with the unmodified App, or we may hold on to the Response under certain conditions, potentially creating a memory leak. This needs further investigation.

Hendrik Liebau committed Aug 29, 2025 at 17:22 UTC aad7c664ffbde52e5d8004b542d83d6d4b7a32a0

1 file changed +8 -3

packages/react-client/src/ReactFlightClient.js

+8 -3

@@ -1010,10 +1010,15 @@ export function reportGlobalError(

1010 if (__DEV__) {

1011 const debugChannel = response._debugChannel;

1012 if (debugChannel !== undefined) {

1013 - // If we don't have any more ways of reading data, we don't have to send any

1014 - // more neither. So we close the writable side.

1013 + // If we don't have any more ways of reading data, we don't have to send

1014 + // any more neither. So we close the writable side.

1015 closeDebugChannel(debugChannel);

1016 response._debugChannel = undefined;

1017 + // Make sure the debug channel is not closed a second time when the

1018 + // Response gets GC:ed.

1019 + if (debugChannelRegistry !== null) {

1020 + debugChannelRegistry.unregister(response);

1021 + }

1022 }

1023 }

1024 }

@@ -2434,7 +2439,7 @@ function ResponseInstance(

2439 // When a Response gets GC:ed because nobody is referring to any of the

2440 // objects that lazily load from the Response anymore, then we can close

2441 // the debug channel.

2437 - debugChannelRegistry.register(this, debugChannel);

2442 + debugChannelRegistry.register(this, debugChannel, this);

2443 }

2444 }

2445 }