fix: guard addStreamMessage with isStreaming() to avoid stream-completed race#1208
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HaiyiMei wants to merge 1 commit into
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fix: guard addStreamMessage with isStreaming() to avoid stream-completed race#1208HaiyiMei wants to merge 1 commit into
HaiyiMei wants to merge 1 commit into
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…ted race After cyrusagents#1141 started calling streamingPrompt.complete() on result message under non-warm mode, there is a brief window where isRunning() still returns true but streamingPrompt.completed is already true. Webhook handlers that called existingRunner.addStreamMessage(...) on the basis of isRunning() alone would throw "Cannot add message to completed stream", silently dropping the user's message after Cyrus had already posted "I've queued up your message as guidance". IAgentRunner.isStreaming?() is documented in agent-runner-types.ts as "Use this to guard calls to addStreamMessage()". ChatSessionHandler.ts already does this. Add it at the four EdgeWorker.ts sites that did not: - handlePromptWithStreamingCheck (the main prompted-webhook entry) - resumeAgentSession (early-return when stream is alive) - issue-update streaming delivery (CYPACK-954 path) - base-branch change notification streaming When the guard fails, callers fall through to query({resume: ...}) and the user's comment is delivered via the normal resume path instead of being lost. Test mock factory for the issue-update path updated to mirror isRunning into isStreaming so the streaming branch is reachable. Repro: send a comment in an active agent session thread; if it arrives in the window between SDK result emission and runner teardown (~tens of ms), Cyrus acknowledges "queued up as guidance" but logs the throw and drops the message. With this fix the comment falls through to resume.
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Bug
After #1141 began calling
streamingPrompt.complete()on the SDK result message under non-warm mode, a brief window opens where:ClaudeRunner.isRunning()still returnstrue(becausesessionInfo.isRunningis flipped after the for-await loop exits — seeClaudeRunner.ts:806)streamingPrompt.completedis alreadytrueWebhook handlers that guarded
addStreamMessage(...)withisRunning()alone passed the check, thenStreamingPrompt.addMessage()threw"Cannot add message to completed stream". The exception was logged but not caught, so the user's comment was silently dropped — after Cyrus had already posted"I've queued up your message as guidance"in the Linear UI. Confusing failure mode.Symptom from production logs
User's view: they replied to an agent session, saw "queued as guidance", waited 9 minutes for the agent to act on it, nothing happened. The comment had to be re-posted to take effect.
Fix
IAgentRunner.isStreaming?()is already part of the interface — seeagent-runner-types.ts:296:EdgeWorker.ts:1512— base-branch change notification streamingEdgeWorker.ts:3521— issue-update streaming delivery (CYPACK-954 path)EdgeWorker.ts:6619—handlePromptWithStreamingCheck(main prompted-webhook entry)EdgeWorker.ts:6706—resumeAgentSessionearly-return when stream is aliveWhen the guard fails, callers fall through to the proper
query({ resume: ... })path, preserving the user's message instead of dropping it.Test changes
EdgeWorker.issue-update-multiple-sessions.test.ts— the mock factory at line 84 was missingisStreamingon the agent runner mock. Other test files already mock both. AddedisStreaming: vi.fn().mockReturnValue(isRunning)so the streaming branch is reachable in tests.Verification
pnpm --filter cyrus-edge-worker test:run).pnpm --filter cyrus-edge-worker typecheckclean.pnpm buildclean across the workspace.Related
c0495f3d) — introduced thestreamingPrompt.complete()on result behavior under non-warm mode. This PR is a follow-up to harden the call sites that the change exposed.