public void TestServiceShouldCallRepoMethodOnce() { //Given var mockRepo = new Mock<IWatchRepository>(); var service = new WatchService(mockRepo.Object); //When mockRepo.Setup(mr => mr.RemoveAlarmSubscriptionFromWatch(It.IsAny<AlarmWatch>())); service.DeleteAlarmSubscriptionFromWatch(new AlarmWatch()); //Then mockRepo.Verify(mr => mr.RemoveAlarmSubscriptionFromWatch(It.IsAny<AlarmWatch>())); }