The same test passes or fails depending on a random sleep. When I deliver the old coupon completion after the new attempt starts, the new attempt becomes complete too. I want to pin down that order without waiting for lucky timing.
Control delivery explicitly: start both distinct attempts, release the older completion, and assert the newer remains pending before delivering its own result; repeat the older delivery to test duplication separately.
That order reproduces it every time. The old event carries its own attempt ID, but the handler updates the currently selected attempt. Developer has the failing test; repair not checked yet.