public async Task GetTotalNumberOfVotersForEventTest() { Guid eId = new Guid(); Event e = new Event { Id = eId }; VoteForPlace vp1 = new VoteForPlace { Id = new Guid("00000000-0000-0000-0000-000000000000"), UserId = "0" }; VoteForPlace vp2 = new VoteForPlace { Id = new Guid("00000000-0000-0000-0000-000000000001"), UserId = "1" }; Place p1 = new Place { Id = new Guid("00000000-0000-0000-0000-000000000000"), Event = e, EventId = eId, VotesForPlace = new List <VoteForPlace> { vp1, vp2 } }; Place p2 = new Place { Id = new Guid("00000000-0000-0000-0000-000000000001"), Event = e, EventId = eId }; List <Place> places = new List <Place> { p1, p2 }; VoteForDate vd1 = new VoteForDate { Id = new Guid("00000000-0000-0000-0000-000000000000"), UserId = "1" }; VoteForDate vd2 = new VoteForDate { Id = new Guid("00000000-0000-0000-0000-000000000001"), UserId = "2" }; TimeSlot t1 = new TimeSlot { Id = new Guid("00000000-0000-0000-0000-000000000000"), Event = e, EventId = eId, VotesForDate = new List <VoteForDate> { vd1, vd2 } }; TimeSlot t2 = new TimeSlot { Id = new Guid("00000000-0000-0000-0000-000000000001"), Event = e, EventId = eId }; List <TimeSlot> timeslots = new List <TimeSlot> { t1, t2 }; var tcs1 = new TaskCompletionSource <IList <Place> >(); tcs1.SetResult(places); var tcs2 = new TaskCompletionSource <IList <TimeSlot> >(); tcs2.SetResult(timeslots); _eventDetailsService.Setup(mock => mock.GetPlacesWithVotes(eId)).Returns(tcs1.Task); _eventDetailsService.Setup(mock => mock.GetDatesWithVotes(eId)).Returns(tcs2.Task); var task = await _votingService.GetTotalNumberOfVotersForEvent(eId); _eventDetailsService.Verify(mock => mock.GetPlacesWithVotes(eId), Times.Once(), "Method GetPlacesWithVotes was not called or was called more than once (or its parameters were wrong)."); _eventDetailsService.Verify(mock => mock.GetDatesWithVotes(eId), Times.Once(), "Method GetPlacesWithVotes was not called or was called more than once (or its parameters were wrong)."); Assert.AreEqual(3, task, "Returned number of voters is different to the actual value"); }