public void DeletedAssignmentShoundNotExistInDatabase() { //Arrange NewAssignmentVm assignmentToAdd = new NewAssignmentVm() { Id = 1, Name = "test" }; var options = new DbContextOptionsBuilder <Context>() .UseInMemoryDatabase("UsersDirectoryMVC") .Options; var config = new MapperConfiguration(c => { c.AddProfile(new MappingProfile()); }); var mapper = config.CreateMapper(); using (var context = new Context(options)) { //Act var assignmentService = new AssignmentService(mapper, new AssignmentRepository(context)); var result = assignmentService.AddAssignment(assignmentToAdd); assignmentService.DeleteAssignment(1); var deletedAssignment = assignmentService.GetAssignmentDetails(1); //Assert deletedAssignment.Should().BeNull(); } }