Unit tests

In ProductService, let's make sure our service returns product data without failure by testing it. Here we will use fake objects to do so, follow these steps:

1. Add a new folder and name it Fake in the FlixOne.BookStore.ProductService.UnitTests project.
2. Under the Fake folder add the ProductData.cs class and add the following code:

public class ProductData
{
  public IEnumerable<ProductViewModel> GetProducts()
  {
    var productVm = new List<ProductViewModel>
    {
      new ProductViewModel
      {
        CategoryId = Guid.NewGuid(),
        CategoryDescription = "Category Description",
        CategoryName = "Category Name",
        ProductDescription = "Product Description",
        ProductId = Guid.NewGuid(),
        ProductImage = "Image full path",
        ProductName = "Product Name",
        ProductPrice = 112M
      },
      new ProductViewModel
      {
        CategoryId = Guid.NewGuid(),
        CategoryDescription = "Category Description-01",
        CategoryName = "Category Name-01",
        ProductDescription = "Product Description-01",
        ProductId = Guid.NewGuid(),
        ProductImage = "Image full path",
        ProductName = "Product Name-01",
        ProductPrice = 12M
      }
    };
    return productVm;
  }
  public IEnumerable<Product> GetProductList()
  {
    return new List<Product>
    {
      new Product
      {
        Category = new Category(),
        CategoryId = Guid.NewGuid(),
        Description = "Product Description-01",
        Id = Guid.NewGuid(),
        Image = "image full path",
        Name = "Product Name-01",
        Price = 12M
      },
      new Product
      {
        Category = new Category(),
        CategoryId = Guid.NewGuid(),
        Description = "Product Description-02",
        Id = Guid.NewGuid(),
        Image = "image full path",
        Name = "Product Name-02",
        Price = 125M
      }
    };
  }
}

In the previous code snippet, we are creating fake data by creating two lists of ProductViewModel and Product.

3. Add the Services folder in the FlixOne.BookStore.ProductService.UnitTests project.
4. Under the Services folder add the ProductTests.cs class.

5. Open NuGet Manager and then search for and add moq, refer to the following screenshot:

6. Add the following code to the ProductTests.cs class:

public class ProductTests
{
    [Fact]
    public void Get_Returns_ActionResults()
    {
      // Arrange
      var mockRepo = new Mock<IProductRepository>();
      mockRepo.Setup(repo => repo.GetAll()).
      Returns(new ProductData().GetProductList());
      var controller = new ProductController(mockRepo.Object);
      // Act
      var result = controller.GetList();
      // Assert
      var viewResult = Assert.IsType<OkObjectResult>(result);
      var model = Assert.IsAssignableFrom<IEnumerable<
      ProductViewModel>>(viewResult.Value);
      Assert.NotNull(model);
      Assert.Equal(2, model.Count());
    }
}

In the preceding code example, which is a unit test example, we are mocking our repository and testing the output of our WebAPI controller. This test is based on the AAA technique; it will be passed if you meet the mocked data during setup.