feat: graceful stream cancellation on 403

[heyitsaamir]

Summary

• Detect when Teams stops a stream (user presses Stop or 2-min timeout) via 403 response and cancel immediately instead of silently retrying until timeout
• Add StreamCancelledError class and canceled property to IStreamer interface
• HttpStream.send() catches 403, sets canceled flag, and throws StreamCancelledError
• emit() and close() bail out immediately when canceled
• retry() skips retries for StreamCancelledError (no point retrying a permanent cancellation)
• flush() suppresses error log for expected cancellation
• app.process catches StreamCancelledError and returns 200 so Teams doesn't retry

Ports teams.py#337 to TypeScript.

To test, I ran a streaming bot, press Stop mid-stream — verify no held connection, verify future messages weren't impacted, verified that stream didn't restart b/c of a 500.

[Copilot]

Pull request overview

Note

Copilot was unable to run its full agentic suite in this review.

This PR ports Teams stream-cancellation handling to TypeScript by detecting “stream stopped” via HTTP 403 and short-circuiting future streaming work (no retries, no noisy logs), while ensuring the inbound request still returns 200 to prevent Teams retries.

Changes:

• Introduces StreamCancelledError and adds a canceled flag to IStreamer.
• Updates HttpStream to mark streams canceled on 403, block emit/send/close when canceled, and suppress expected cancellation logs.
• Updates retry() and $process() to avoid retrying/handling cancellations as failures.

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 8 comments.

Show a summary per file

File	Description
packages/apps/src/utils/promises/retry.ts	Skips retries by rethrowing StreamCancelledError immediately.
packages/apps/src/types/streamer.ts	Adds StreamCancelledError and extends IStreamer with canceled.
packages/apps/src/http/http-stream.ts	Detects 403 cancellations, sets _canceled, bails early in emit/close/send, and suppresses cancellation logging.
packages/apps/src/http/http-stream.spec.ts	Adds test coverage around 403-driven cancellation and post-cancel behavior.
packages/apps/src/app.process.ts	Treats StreamCancelledError as a successful (200) outcome so Teams won’t retry.

Comments suppressed due to low confidence (1)

packages/apps/src/http/http-stream.ts:1

• Given the while ((this.queue.length || !this.id) && !this._canceled) loop condition, control flow shouldn’t reach the if (!this.id) block unless the earlier timeout/cancel paths return (and cancel already returns just above). This makes the no stream id set warning effectively unreachable/redundant; consider removing it or restructuring the loop/conditions so the warning is emitted on a reachable path.

import {

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[heyitsaamir]

This change is part of the following stack:

• feat: graceful stream cancellation on 403 #513 ◀

_{Change managed by git-spice.}

[rajan-chari]

Reviewed this with a few folks who have streaming context. Looks good — clean design.

Architecture trace works end-to-end: 403 in send() → _canceled flag → StreamCancelledError → retry() re-throws immediately → flush() suppresses log → emit()/close() bail early → app.process returns 200. Each layer does one thing.

403 assumption is safe. Mid-stream, auth has already succeeded (first send() established the stream ID). A 403 at that point is cancellation — Stop button or 2-min timeout. Token expiry would be 401, and permission failures would hit on the first send. Even edge cases like admin revoking permissions mid-stream — treating as cancellation (stop retrying, return 200) is the correct behavior.

Minor notes (non-blocking):

• IStreamer.canceled is technically breaking for custom implementors, but only HttpStream implements it — worth a minor version note
• Double cancel check in close() (before and after wait loop) is good — catches the mid-wait race
• Nice to have: test cases for retry() with StreamCancelledError and mid-wait cancellation in close()

LGTM