public void CanCreateCategories()
        {
            // Arrange
            // - create the mock repository
            var mock = new Mock<IProductRepository>();
            mock.Setup(m => m.Products).Returns(
                new[]
                    {
                        new Product { ProductID = 1, Name = "P1", Category = "Apples" },
                        new Product { ProductID = 2, Name = "P2", Category = "Apples" },
                        new Product { ProductID = 3, Name = "P3", Category = "Plums" },
                        new Product { ProductID = 4, Name = "P4", Category = "Oranges" },
                    }.AsQueryable());

            // Arrange - create the controller
            var target = new NavController(mock.Object);

            // Act = get the set of categories
            string[] results = ((IEnumerable<string>)target.Menu().Model).ToArray();

            // Assert
            Assert.AreEqual(results.Length, 3);
            Assert.AreEqual(results[0], "Apples");
            Assert.AreEqual(results[1], "Oranges");
            Assert.AreEqual(results[2], "Plums");
        }
        public void IndicatesSelectedCategory()
        {
            // Arrange
            // - create the mock repository
            var mock = new Mock<IProductRepository>();
            mock.Setup(m => m.Products).Returns(
                new[]
                    {
                        new Product { ProductID = 1, Name = "P1", Category = "Apples" },
                        new Product { ProductID = 4, Name = "P2", Category = "Oranges" },
                    }.AsQueryable());

            // Arrange - create the controller
            var target = new NavController(mock.Object);

            // Arrange - define the category to selected
            string categoryToSelect = "Apples";

            // Action
            string result = target.Menu(categoryToSelect).ViewBag.SelectedCategory;

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