public void CallSaveChangesOnUsitData_WhenAirportIsPassed() { // Arrange var mockedData = new Mock <IUsitData>(); var airportService = new AirportService(mockedData.Object); var mockedAirportRepository = new Mock <IGenericRepository <Airport> >(); mockedData.Setup(d => d.Airports).Returns(mockedAirportRepository.Object); var airport = new Airport() { Id = 2, Name = "Name" }; // Act airportService.AddAirport(airport); // Assert mockedData.Verify(d => d.SaveChanges(), Times.Once); }