fix: useStream can now handle multiple streams per component lifetime

[ianmacartney]

Summary

Fixes #19

The useStream hook was unable to drive more than one stream per component lifetime. After the first stream completed, subsequent calls with a new streamId silently skipped the HTTP POST and fell back to the database query, losing the real-time streaming UX.

Root Causes Addressed

1. streamStarted ref was set but never cleared

The original code used a streamStarted ref intended as a React Strict Mode guard, but it permanently blocked all future streams after the first one completed.

Fix: Replaced with activeStreamRef that tracks the current streamId. This serves as both:

• A Strict Mode guard (same streamId won't re-trigger)
• A mechanism to detect when a new stream should be started

2. streamBody and streamEnded were never reset between streams

When streamId changed, the state from the previous stream would persist, potentially causing text concatenation issues.

Fix: Both states are now reset when a new streamId is detected.

3. No AbortController caused stale stream reads to leak

If the component re-rendered with a new streamId while a previous fetch was mid-read, the old reader.read() loop would continue calling setStreamBody, mixing text across streams.

Fix: Added AbortController to cleanup in-flight requests when:

• Component unmounts
• streamId changes to a new value

Errors from aborted fetches are silently ignored to avoid false error states.

4. Minor performance improvement

TextDecoder was being allocated per chunk inside the while loop.

Fix: Now allocated once per stream and reused.

Testing

• TypeScript type checking passes (npm run typecheck)
• ESLint passes (npm run lint)
• Tests pass (npm test)

Slack Thread

  

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npm i https://pkg.pr.new/@convex-dev/persistent-text-streaming@20

commit: cbb178d