Deflake queue-deallocation tests by awaiting the enqueued task#78
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The four `*_executesAfterQueueIsDeallocated` tests confirmed the final enqueued task ran by waiting on `Expectation.fulfillment(withinSeconds: 30)`. That is a wall-clock race: the expectation pits a `Task.sleep(30s)` against `fulfill()`, and `fulfill()` itself hops through an extra detached task. Under the `-test-iterations 100 -run-tests-until-failure` stress harness on a slow, contended simulator (visionOS), the cooperative pool can be starved long enough that the sleep wins before the queued work is scheduled, producing a false failure. `Task(on:)` captures only its `Delivery`/`Semaphore` — never the `FIFOQueue` — so holding the returned handle does not retain the queue, and the `weak queue == nil` assertion still holds. Capture the last enqueued task and `await` its value instead. This removes the wall-clock race entirely and is a strictly stronger check: it waits for the work to actually complete rather than for a side-channel flag, while the `Counter` assertions still verify ordering. The tests now finish in ~1ms regardless of runner speed. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Codecov Report✅ All modified and coverable lines are covered by tests. Additional details and impacted files@@ Coverage Diff @@
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What
Rewrite the four
*_executesAfterQueueIsDeallocated()tests inFIFOQueueTeststoawaitthe final enqueued task's value instead of waiting onExpectation.fulfillment(withinSeconds: 30).Why
These tests were the source of the intermittent
visionOS_2CI failures (Expectation not fulfilled within 30 seconds, e.g. iteration 8/100). The expectation is a wall-clock race: it pits aTask.sleep(30s)againstfulfill(), andfulfill()itself hops through an extra detachedTask. Under the-test-iterations 100 -run-tests-until-failurestress harness on a slow, contended simulator, the cooperative pool can be starved long enough that the sleep wins before the queued work runs — a false failure. The identical code passes on macOS/iOS/Linux; it's purely runner-speed sensitivity.How it stays correct
Task(on:)captures only itsDelivery/Semaphore, never theFIFOQueue, so holding the returned handle doesn't retain the queue — theweak queue == nilassertion still holds. Awaiting the last enqueued task is a strictly stronger check than the old expectation: it waits for the work to actually complete rather than for a side-channel flag, and theCounterassertions still verify execution order. Tests now complete in ~1ms regardless of runner speed.The other
fulfillment(withinSeconds:)call sites (e.g.ExpectationTests, which deliberately tests timeout behavior) are left unchanged.🤖 Generated with Claude Code