public async Task GetListByEventGuid_ReturnsGuestList() { // arrange var eventGuid = Guid.NewGuid().ToString(); List <Guest> guests = new List <Guest>(); guests.Add(new Guest { guestId = 123, name = "Guest1", isGoing = true, eventId = 1, eventGuid = eventGuid }); guests.Add(new Guest { guestId = 124, name = "Guest2", isGoing = true, eventId = 1, eventGuid = eventGuid }); guests.Add(new Guest { guestId = 125, name = "Guest3", isGoing = false, eventId = 1, eventGuid = eventGuid }); guests.Add(new Guest { guestId = 126, name = "Guest4", isGoing = null, eventId = 1, eventGuid = eventGuid }); _guestQueryMock.Setup(x => x.GetListByEventGuid(guests.First().eventGuid)) .Returns(Task.Factory.StartNew(() => guests)); // act var task = await _sut.GetListByEventGuid(guests.First().eventGuid); // assert Assert.IsType <OkObjectResult>(task); var result = task as OkObjectResult; var guestsResult = result.Value as List <Guest>; Assert.Equal(guests, guestsResult); }