public void CheckTagExistAfterDelete() { //Arrange Tag tag1 = new Tag() { Id = 66, Name = "test" }; Tag tag2 = new Tag() { Id = 77, Name = "test" }; var options = new DbContextOptionsBuilder <Context>() .UseInMemoryDatabase(databaseName: "UsersDirectoryMVC") .Options; using (var context = new Context(options)) { //Act var assignmentRepository = new AssignmentRepository(context); assignmentRepository.AddTag(tag1); assignmentRepository.AddTag(tag2); assignmentRepository.DeleteTag(66); var gerAssignment1 = assignmentRepository.GetTag(66); var gerAssignment2 = assignmentRepository.GetTag(77); //Assert gerAssignment1.Should().BeNull(); gerAssignment2.Should().Equals(tag2); } }