public void Add_Subscriber_To_Db() { var mockDbSet = new Mock <DbSet <Subscriber> >(); var mockContext = new Mock <RentalContext>(); mockContext.Setup(r => r.Subscribers).Returns(mockDbSet.Object); var service = new SubscriberService(mockContext.Object); service.Add(new Subscriber()); mockContext.Verify(a => a.Add(It.IsAny <Subscriber>()), Times.Once); mockContext.Verify(s => s.SaveChanges(), Times.Once); }