effect-concurrency-testing

Deterministic tests for Effect concurrency primitives require coordinating readiness using Latch, Deferred, or PubSub before asserting mutations, ensuring fibers, streams, and subscriptions synchronize correctly without missing events.

Effect PubSub tests flake when subscriptions are not fully ready before publishing events. You must synchronize subscription readiness using coordination primitives like Latch or Deferred to guarantee deterministic event delivery.

Use TestClock for time-dependent logic in Effect streams only when you need to control scheduled time progression. Apply it carefully alongside readiness synchronization to avoid busy polling and verify deterministic fiber completion behavior.

Testing Effect Fiber interruption and completion status requires deterministic scheduling patterns. Coordinate fibers using Latch or Deferred to verify interruption correctness and controlled completion without relying on busy polling.

Verify SubscriptionRef change streams by ensuring subscription readiness before applying mutations. Synchronize the stream attachment using Latch or Deferred so change events are captured deterministically, preventing race conditions and missed updates.

Yes, Deferred and Latch coordinate readiness for Effect stream finalizers by gating stream attachment and lifecycle progression. This scoped lifecycle management ensures finalizers and error handling execute predictably during concurrent workflow tests.