Fix flaky LangGraph timeout tests#1495
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tconley1428 merged 7 commits intomainfrom May 1, 2026
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The test activities slept for 1s with a 100ms start_to_close_timeout. Since Temporal does not actively cancel an activity when start_to_close_timeout fires (it just rejects late completions), the server processing the activity completion raced with it processing the timeout, and on slow runners (Windows CI) the completion sometimes won — causing test_timeout to fail with "DID NOT RAISE WorkflowFailureError". Increase the activity sleep to 30s so the timer reliably fires long before the activity could complete naturally. Worker-shutdown cancellation cleans up the still-sleeping activity when the test exits its `async with Worker(...)` block, so runtime is unchanged. Same fix applied to slow_task, used by the otherwise-identical pattern in test_per_task_activity_options_override.
brianstrauch
approved these changes
Apr 30, 2026
Replaces the 30s sleep with await asyncio.Event().wait() to make the intent explicit: the activity has no natural exit, so it can only end via the start_to_close_timeout firing or worker-shutdown cancellation.
The function never sleeps anymore — it waits on an Event() that's never set — so "slow" was misleading. waiting_task names what it actually does.
Sushisource
approved these changes
Apr 30, 2026
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Summary
tests/contrib/langgraph/test_timeout.pyslept for 1s with a 100msstart_to_close_timeout. Temporal does not actively cancel an activity whenstart_to_close_timeoutfires — it just rejects late completions — so the server processing the activity completion raced with it processing the timeout. On slow runners (Windows CI) the completion sometimes won, causingtest_timeoutto fail withFailed: DID NOT RAISE WorkflowFailureError(e.g. this run).await asyncio.Event().wait()so the activity has no natural exit at all — the only way out is thestart_to_close_timeoutfiring or worker-shutdown cancellation when the test exits itsasync with Worker(...)block. Test runtime is unchanged (~1.3s locally).test_per_task_activity_options_override, which had the identical pattern. Renamed it fromslow_tasktowaiting_tasksince it no longer sleeps.Test plan
uv run pytest tests/contrib/langgraph/test_timeout.py— passes consistently across multiple local runsuv run pytest tests/contrib/langgraph/test_e2e_functional.py::TestFunctionalAPIPerTaskOptions— passes