barrier-concurrency-testing

Instead of setTimeout (flaky) or sleep (slow), use barriers to pause execution at exact interleave points. The test controls when each concurrent operation proceeds, making race condition tests deterministic and reproducible on every run.

When to use: Testing concurrent operations, flush conflicts, parallel mutations, race windows between read and write, lock contention scenarios, any code where timing affects correctness.

When not to use: Sequential-only code, simple unit tests, UI components, read-only operations, code with no concurrency concerns.

使用障礙和延遲承諾進行確定性競爭條件測試。以可重現的交錯控制取代基於 setTimeout 的片狀計時測試。 來源：apankov1/quality-engineering。