mockFirebasePerformance top-level property
Stubs the Firebase Performance pigeon channel.
Without a mock handler, its HttpMetric#start/stop calls (awaited by the
Dio performance interceptor on every request) are routed to the real
platform messenger and only complete on the real event loop — which forces
tests to drive the request with runAsync instead of pump. Stubbing the
channel makes those calls resolve on the fake clock, so the whole HTTP flow
settles under pump/pumpAndSettle.
Implementation
final mockFirebasePerformance = MockFirebasePerformance._();