public async Task InsertTournament_InputIsTournamentData_ReturnsCreated() { //Arrange tournamentServiceMock.Setup(tournamentService => tournamentService.InsertTournamentAsync(It.IsAny <TournamentDTO>())) .ReturnsAsync((TournamentDTO tournamentDTO) => { tournamentsContext.Add(tournamentDTO); return(tournamentDTO); }); int tournamentsContextLength = tournamentsContext.Count; //Act var createdResult = (await tournamentController.Post(tournamentDTO)) as CreatedResult; //Assert Assert.IsNotNull(createdResult); Assert.AreEqual(201, createdResult.StatusCode); Assert.AreEqual(tournamentsContextLength + 1, tournamentsContext.Count); }