fix: avoid unhandled rejection when DeferrableMap.getDeferred is aborted

[Abhishek-B-R]

Summary

DeferrableMap.getDeferred(key, signal) (exposed as remoteParticipant.dataTracks.getDeferred()) removes its abort listener with future.promise.finally(...). .finally() returns a new promise that re-rejects with the same reason, and nothing handles that one. So when the signal aborts, the caller gets the AbortError on the promise it awaited, and a second copy of the same error is reported as an unhandled rejection. Wrapping the call in try/catch doesn't help, so apps that cancel a wait for a data track see "Uncaught (in promise) AbortError" in the console, and error trackers that listen for unhandledrejection record it.

Changes

• Remove the listener with .then(cleanup, cleanup) instead of .finally(cleanup), so the internal chain handles both outcomes. The promise returned to the caller is unchanged and still rejects with DeferrableMapAbortError.
• Adds src/utils/deferrable-map.test.ts (there was no test file for DeferrableMap): existing key, resolve on set, already aborted signal, and abort while pending.
• Adds a patch changeset.

Testing

The abort test catches the rejection, waits one macrotask, then checks process.on('unhandledRejection') saw nothing. On main it fails with one unhandled AbortError (reason 'gave up'); with the fix all 4 tests pass. pnpm test passes (57 files, 977 tests), and tsc --noEmit, eslint and prettier are clean.

[changeset-bot]

🦋 Changeset detected

Latest commit: 91385fc

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

Name	Type
livekit-client	Patch

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[devin-ai-integration]

✅ Devin Review: No Issues Found

Devin Review analyzed this PR and found no bugs or issues to report.

[1egoman]

This looks great to me, great catch and thank you for the contribution.

@Abhishek-B-R Would you be able to click the "CLA not signed yet" button and sign the CLA? Once you do this I'll merge.