public void Add_New_LibraryCard() { var mockSet = BuildMock(); var mockCtx = new Mock <LibraryDbContext>(); mockCtx.Setup(c => c.LibraryCards).Returns(mockSet.Object); var sut = new LibraryCardService(mockCtx.Object); sut.Add(new LibraryCard()); mockCtx.Verify(s => s.Add(It.IsAny <LibraryCard>()), Times.Once()); mockCtx.Verify(c => c.SaveChanges(), Times.Once()); }