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Fix crash in async void TurboModule methods when NSException is thrown #55390

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Fix crash in async void TurboModule methods when NSException is thrown #55390

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8 changes: 7 additions & 1 deletion ...act-native/ReactCommon/react/nativemodule/core/platform/ios/ReactCommon/RCTTurboModule.mm
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Original file line number Diff line number Diff line change
Expand Up @@ -461,7 +461,13 @@ TraceSection s(
@try {
[inv invokeWithTarget:strongModule];
} @catch (NSException *exception) {
throw convertNSExceptionToJSError(runtime, exception, std::string{moduleName}, methodNameStr);
// Cannot rethrow C++ exceptions from async dispatch - nothing can catch them.
// Log the error for debugging purposes instead of crashing.
RCTLogError(
@"Exception thrown while invoking async method %s.%s: %@",
moduleName,
methodNameStr.c_str(),
exception);
Comment on lines +465 to +470
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@RSNara RSNara Feb 3, 2026 •
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@Luxlorys, let's handle errors in async methods consistently.

Is there a strong reason for us to do something different in these changed lines vs here:

https://github.com/Luxlorys/react-native/blob/9f41b14761389b57f4947e89051a7865122ba4c6/packages/react-native/ReactCommon/react/nativemodule/core/platform/ios/ReactCommon/RCTTurboModule.mm#L399-L405

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@Luxlorys Luxlorys Feb 3, 2026

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Lines 399-405 (Promise-based async methods) can re-throw NSException because they execute within the createPromise() wrapper infrastructure (lines 253-360).
When the exception is re-thrown at line 404, it's caught by the Promise wrapper which can then reject the Promise and communicate the error back to JavaScript
through the resolve/reject blocks.

Async void methods execute through a fundamentally different code path:

  1. They call performVoidMethodInvocation() which dispatches directly via invokeAsync() to a background queue
  2. There's no Promise wrapper, no resolve/reject blocks, no error communication channel
  3. The JS call has already returned undefined before the async work executes
  4. Any exception thrown (whether C++ or NSException) has nothing to catch it on the dispatch queue

If we used the same approach as line 404 (@throw exception;) for void methods, the app would still crash because there's no infrastructure to catch the
re-thrown NSException in the dispatch block's execution context.

Correct me if I missed something, I'm new here

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@Luxlorys Luxlorys Feb 9, 2026

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@RSNara Hey, check message above when you have time, please.

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@RSNara RSNara Feb 26, 2026

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Ah! So you're saying that we should be throwing in the promise case.

} @finally {
[retainedObjectsForInvocation removeAllObjects];
}
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