public async void Get_null_record() { var mock = new ServiceMockFacade <ITenantVariableRepository>(); mock.RepositoryMock.Setup(x => x.Get(It.IsAny <string>())).Returns(Task.FromResult <TenantVariable>(null)); var service = new TenantVariableService(mock.LoggerMock.Object, mock.RepositoryMock.Object, mock.ModelValidatorMockFactory.TenantVariableModelValidatorMock.Object, mock.BOLMapperMockFactory.BOLTenantVariableMapperMock, mock.DALMapperMockFactory.DALTenantVariableMapperMock); ApiTenantVariableResponseModel response = await service.Get(default(string)); response.Should().BeNull(); mock.RepositoryMock.Verify(x => x.Get(It.IsAny <string>())); }