public void TestGetAllPhoto() { IEnumerable <Photo> ienumablePhoto = new List <Photo>() { photo }; mockPhotoRepository.Setup(x => x.GetAll(It.IsAny <string>())).Returns(ienumablePhoto); var photoService = new PhotoService(mockPhotoRepository.Object); IEnumerable <Photo> ienumablePhotoReturn = photoService.GetAllPhoto("5d0b233b1a0a4200017de6c9"); Photo photoActual = ienumablePhotoReturn.FirstOrDefault(); Assert.AreEqual(photoActual, photo); }