gistfile1.cs

       [Test]
        public void When_requesting_the_admin_categories_page_result_is_correct()
        {
            const int expectedCategoryCount = 3;
            const string expectedViewName = "Categories";
            var repository = new Mock<IRepository<Category>>();

            repository.Setup(x => x.GetAll()).Returns(new List<Category>
                                                          {
                                                              new Category(),
                                                              new Category(),
                                                              new Category()
                                                          });

            var controller = new AdminController(repository.Object);
            var result = controller.Categories();
            result.Should().BeAssignableTo<ActionResult>();
            result.AssertViewRendered().ForView(expectedViewName);
            result.Model.Should().BeAssignableTo<CategoriesListViewModel>();

            ((CategoriesListViewModel) result.Model).Categories.Count.Should().Be(expectedCategoryCount);
        }