fix(react): prevent double resume in React StrictMode #11509
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jacobwisniewski
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lgrammel
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please add a patch changeset |
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for future PRs please try to follow our PR description template |
Add a ref guard to prevent resumeStream() from being called twice when React StrictMode double-invokes effects during development. This fixes an issue where refreshing the page mid-stream would cause duplicate stream requests, leading to: - Duplicated/repeated text in the UI - Multiple concurrent stream consumers - Inconsistent message state The fix adds a hasResumedRef that tracks whether resume has already been attempted, preventing the second invocation from making another request. Fixes vercel#9610
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lgrammel
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| const hasResumedRef = useRef(false); | ||
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| useEffect(() => { | ||
| if (resume) { | ||
| if (resume && !hasResumedRef.current) { | ||
| hasResumedRef.current = true; | ||
| chatRef.current.resumeStream(); | ||
| } | ||
| }, [resume, chatRef]); |
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does the ref need to be reset to false? maybe i missing something here, want to make sure this works on the several resumes not just the 1st one
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Background
When using
useChatwithresume: true, refreshing the page mid-stream causes duplicate stream requests because React StrictMode runs effects twice (mount → unmount → mount). The current implementation has no protection against this:This leads to:
onDatacallbacks being called twice per server writeSummary
This PR adds a ref guard to prevent
resumeStream()from being called twice when React StrictMode double-invokes effects during development.Add a
hasResumedRefthat tracks whether resume has already been attempted:Testing
Added a test case that renders the component in
<React.StrictMode>and verifies only one resume request is made despite effects running twice.Related Issues
Fixes #9610