public void GetById_Should_ReturnNull_IfParameterIdIsNull()
        {
            // Arrange
            var mockedDbSet = new Mock <IEfCarSystemDbSetCocoon <AdvertImage> >();

            // Act
            var advertImageService = new AdvertImageService(mockedDbSet.Object);
            var result             = advertImageService.GetById(null);

            // Assert
            Assert.That(result, Is.Null);
        }
        public void GetById_Should_ReturnCorrectFile_IfParameterIdIsValid_AndThereIsFileWithIdEqualOfParamId()
        {
            // Arrange
            var expectedFile = new AdvertImage()
            {
                Id = 1
            };

            var mockedDbSet = new Mock <IEfCarSystemDbSetCocoon <AdvertImage> >();

            mockedDbSet.Setup(f => f.GetById(It.IsAny <int>())).Returns(expectedFile);

            // Act
            var advertImageService = new AdvertImageService(mockedDbSet.Object);
            var result             = advertImageService.GetById(1);

            // Assert
            Assert.AreEqual(result, expectedFile);
        }