public void Can_Retrieve_Image_Data()
        {
            // Arrange
            Product prod = new Product
            {
                ProductID = 2,
                Name = "Test",
                ImageData = new byte[] { },
                ImageMimeType = "image/png"
            };
            Mock<IProductsRepository> mock = new Mock<IProductsRepository>();
            mock.Setup(m => m.Products).Returns(new Product[]
                {
                    new Product { ProductID = 1, Name = "P1"},
                    prod,
                    new Product { ProductID = 3, Name = "P3"}
                }.AsQueryable());
            ProductController target = new ProductController(mock.Object);

            // Act
            ActionResult result = target.GetImage(2);

            // Assert
            Assert.IsNotNull(result);
            Assert.IsInstanceOfType(result, typeof(FileResult));
            Assert.AreEqual(prod.ImageMimeType, ((FileResult)result).ContentType);
        }
        public void Cannot_Retrieve_Image_Data_For_Invalid_ID()
        {
            // Arrange
            Mock<IProductsRepository> mock = new Mock<IProductsRepository>();
            mock.Setup(m => m.Products).Returns(new Product[]
                {
                    new Product { ProductID = 1, Name = "P1"},
                    new Product { ProductID = 2, Name = "P2"},
                    new Product { ProductID = 3, Name = "P3"}
                }.AsQueryable());
            ProductController target = new ProductController(mock.Object);

            // Act
            ActionResult result = target.GetImage(100);

            // Assert
            Assert.IsNull(result);
        }