Mediatr example

src/Web/Controllers/OrderController.cs

@@ -1,9 +1,8 @@
-using Microsoft.AspNetCore.Authorization;
+using MediatR;
+using Microsoft.AspNetCore.Authorization;
 using Microsoft.AspNetCore.Mvc;
-using Microsoft.eShopWeb.ApplicationCore.Interfaces;
-using Microsoft.eShopWeb.ApplicationCore.Specifications;
-using Microsoft.eShopWeb.Web.ViewModels;
-using System.Linq;
+using Microsoft.eShopWeb.Web.Features.MyOrders;
+using Microsoft.eShopWeb.Web.Features.OrderDetails;
 using System.Threading.Tasks;
 
 namespace Microsoft.eShopWeb.Web.Controllers
@@ -13,66 +12,31 @@ namespace Microsoft.eShopWeb.Web.Controllers
     [Route("[controller]/[action]")]
     public class OrderController : Controller
     {
-        private readonly IOrderRepository _orderRepository;
+        private readonly IMediator _mediator;
 
-        public OrderController(IOrderRepository orderRepository)
+        public OrderController(IMediator mediator)
         {
-            _orderRepository = orderRepository;
+            _mediator = mediator;
         }
 
         [HttpGet()]
         public async Task<IActionResult> MyOrders()
         {
-            var orders = await _orderRepository.ListAsync(new CustomerOrdersWithItemsSpecification(User.Identity.Name));
+            var viewModel = await _mediator.Send(new GetMyOrders(User.Identity.Name));
 
-            var viewModel = orders
-                .Select(o => new OrderViewModel()
-                {
-                    OrderDate = o.OrderDate,
-                    OrderItems = o.OrderItems?.Select(oi => new OrderItemViewModel()
-                    {
-                        Discount = 0,
-                        PictureUrl = oi.ItemOrdered.PictureUri,
-                        ProductId = oi.ItemOrdered.CatalogItemId,
-                        ProductName = oi.ItemOrdered.ProductName,
-                        UnitPrice = oi.UnitPrice,
-                        Units = oi.Units
-                    }).ToList(),
-                    OrderNumber = o.Id,
-                    ShippingAddress = o.ShipToAddress,
-                    Status = "Pending",
-                    Total = o.Total()
-
-                });
             return View(viewModel);
         }
 
         [HttpGet("{orderId}")]
         public async Task<IActionResult> Detail(int orderId)
         {
-            var customerOrders = await _orderRepository.ListAsync(new CustomerOrdersWithItemsSpecification(User.Identity.Name));
-            var order = customerOrders.FirstOrDefault(o => o.Id == orderId);
-            if (order == null)
+            var viewModel = await _mediator.Send(new GetOrderDetails(User.Identity.Name, orderId));
+
+            if (viewModel == null)
             {
                 return BadRequest("No such order found for this user.");
             }
-            var viewModel = new OrderViewModel()
-            {
-                OrderDate = order.OrderDate,
-                OrderItems = order.OrderItems.Select(oi => new OrderItemViewModel()
-                {
-                    Discount = 0,
-                    PictureUrl = oi.ItemOrdered.PictureUri,
-                    ProductId = oi.ItemOrdered.CatalogItemId,
-                    ProductName = oi.ItemOrdered.ProductName,
-                    UnitPrice = oi.UnitPrice,
-                    Units = oi.Units
-                }).ToList(),
-                OrderNumber = order.Id,
-                ShippingAddress = order.ShipToAddress,
-                Status = "Pending",
-                Total = order.Total()
-            };
+
             return View(viewModel);
         }
     }

src/Web/Features/MyOrders/GetMyOrders.cs

@@ -0,0 +1,16 @@
+using MediatR;
+using Microsoft.eShopWeb.Web.ViewModels;
+using System.Collections.Generic;
+
+namespace Microsoft.eShopWeb.Web.Features.MyOrders
+{
+    public class GetMyOrders : IRequest<IEnumerable<OrderViewModel>>
+    {
+        public string UserName { get; set; }
+
+        public GetMyOrders(string userName)
+        {
+            UserName = userName;
+        }
+    }
+}

src/Web/Features/MyOrders/GetMyOrdersHandler.cs

@@ -0,0 +1,43 @@
+using MediatR;
+using Microsoft.eShopWeb.ApplicationCore.Interfaces;
+using Microsoft.eShopWeb.ApplicationCore.Specifications;
+using Microsoft.eShopWeb.Web.ViewModels;
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace Microsoft.eShopWeb.Web.Features.MyOrders
+{
+    public class GetMyOrdersHandler : IRequestHandler<GetMyOrders, IEnumerable<OrderViewModel>>
+    {
+        private readonly IOrderRepository _orderRepository;
+
+        public GetMyOrdersHandler(IOrderRepository orderRepository)
+        {
+            _orderRepository = orderRepository;
+        }
+
+        public async Task<IEnumerable<OrderViewModel>> Handle(GetMyOrders request, CancellationToken cancellationToken)
+        {
+            var specification = new CustomerOrdersWithItemsSpecification(request.UserName);
+            var orders = await _orderRepository.ListAsync(specification);
+
+            return orders.Select(o => new OrderViewModel
+            {
+                OrderDate = o.OrderDate,
+                OrderItems = o.OrderItems?.Select(oi => new OrderItemViewModel()
+                {
+                    PictureUrl = oi.ItemOrdered.PictureUri,
+                    ProductId = oi.ItemOrdered.CatalogItemId,
+                    ProductName = oi.ItemOrdered.ProductName,
+                    UnitPrice = oi.UnitPrice,
+                    Units = oi.Units
+                }).ToList(),
+                OrderNumber = o.Id,
+                ShippingAddress = o.ShipToAddress,
+                Total = o.Total()
+            });
+        }
+    }
+}

src/Web/Features/OrderDetails/GetOrderDetails.cs

@@ -0,0 +1,17 @@
+using MediatR;
+using Microsoft.eShopWeb.Web.ViewModels;
+
+namespace Microsoft.eShopWeb.Web.Features.OrderDetails
+{
+    public class GetOrderDetails : IRequest<OrderViewModel>
+    {
+        public string UserName { get; set; }
+        public int OrderId { get; set; }
+
+        public GetOrderDetails(string userName, int orderId)
+        {
+            UserName = userName;
+            OrderId = orderId;
+        }
+    }
+}

src/Web/Features/OrderDetails/GetOrderDetailsHandler.cs

@@ -0,0 +1,47 @@
+using MediatR;
+using Microsoft.eShopWeb.ApplicationCore.Interfaces;
+using Microsoft.eShopWeb.ApplicationCore.Specifications;
+using Microsoft.eShopWeb.Web.ViewModels;
+using System.Linq;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace Microsoft.eShopWeb.Web.Features.OrderDetails
+{
+    public class GetOrderDetailsHandler : IRequestHandler<GetOrderDetails, OrderViewModel>
+    {
+        private readonly IOrderRepository _orderRepository;
+
+        public GetOrderDetailsHandler(IOrderRepository orderRepository)
+        {
+            _orderRepository = orderRepository;
+        }
+
+        public async Task<OrderViewModel> Handle(GetOrderDetails request, CancellationToken cancellationToken)
+        {
+            var customerOrders = await _orderRepository.ListAsync(new CustomerOrdersWithItemsSpecification(request.UserName));
+            var order = customerOrders.FirstOrDefault(o => o.Id == request.OrderId);
+
+            if (order == null)
+            {
+                return null;
+            }
+
+            return new OrderViewModel
+            {
+                OrderDate = order.OrderDate,
+                OrderItems = order.OrderItems.Select(oi => new OrderItemViewModel
+                {
+                    PictureUrl = oi.ItemOrdered.PictureUri,
+                    ProductId = oi.ItemOrdered.CatalogItemId,
+                    ProductName = oi.ItemOrdered.ProductName,
+                    UnitPrice = oi.UnitPrice,
+                    Units = oi.Units
+                }).ToList(),
+                OrderNumber = order.Id,
+                ShippingAddress = order.ShipToAddress,
+                Total = order.Total()
+            };
+        }
+    }
+}

src/Web/Startup.cs

@@ -1,4 +1,5 @@
 using Ardalis.ListStartupServices;
+using MediatR;
 using Microsoft.AspNetCore.Builder;
 using Microsoft.AspNetCore.Diagnostics.HealthChecks;
 using Microsoft.AspNetCore.Hosting;
@@ -81,7 +82,9 @@ public void ConfigureServices(IServiceCollection services)
             ConfigureCookieSettings(services);
 
             CreateIdentityIfNotCreated(services);
-
+
+            services.AddMediatR(typeof(BasketViewModelService).Assembly);
+
             services.AddScoped(typeof(IAsyncRepository<>), typeof(EfRepository<>));
             services.AddScoped<ICatalogViewModelService, CachedCatalogViewModelService>();
             services.AddScoped<IBasketService, BasketService>();
@@ -109,13 +112,12 @@ public void ConfigureServices(IServiceCollection services)
                 options.Conventions.Add(new RouteTokenTransformerConvention(
                          new SlugifyParameterTransformer()));
 
-            });
-            services.AddControllersWithViews();
+            });    
             services.AddRazorPages(options =>
             {
                 options.Conventions.AuthorizePage("/Basket/Checkout");
             });
-
+            services.AddControllersWithViews();
             services.AddControllers();
 
             services.AddHttpContextAccessor();
@@ -207,14 +209,13 @@ public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
                 app.UseHsts();
             }
 
-            app.UseHttpsRedirection();
             app.UseStaticFiles();
             app.UseRouting();
-
+
+            app.UseHttpsRedirection();
             app.UseCookiePolicy();
             app.UseAuthentication();
             app.UseAuthorization();
-
             // Enable middleware to serve generated Swagger as a JSON endpoint.
             app.UseSwagger();
 

src/Web/ViewModels/OrderItemViewModel.cs

@@ -3,15 +3,10 @@
     public class OrderItemViewModel
     {
         public int ProductId { get; set; }
-
         public string ProductName { get; set; }
-
         public decimal UnitPrice { get; set; }
-
-        public decimal Discount { get; set; }
-
+        public decimal Discount => 0;
         public int Units { get; set; }
-
         public string PictureUrl { get; set; }
     }
 }

src/Web/ViewModels/OrderViewModel.cs

@@ -6,15 +6,13 @@ namespace Microsoft.eShopWeb.Web.ViewModels
 {
     public class OrderViewModel
     {
+        private const string DEFAULT_STATUS = "Pending";
+
         public int OrderNumber { get; set; }
         public DateTimeOffset OrderDate { get; set; }
         public decimal Total { get; set; }
-        public string Status { get; set; }
-
-        public Address ShippingAddress { get; set; } 
-
+        public string Status => DEFAULT_STATUS;
+        public Address ShippingAddress { get; set; }
         public List<OrderItemViewModel> OrderItems { get; set; } = new List<OrderItemViewModel>();
-
     }
-
 }

src/Web/Web.csproj

@@ -14,6 +14,9 @@
 
   <ItemGroup>
     <PackageReference Include="Ardalis.ListStartupServices" Version="1.1.3" />
+
+    <PackageReference Include="MediatR" Version="7.0.0" />
+    <PackageReference Include="MediatR.Extensions.Microsoft.DependencyInjection" Version="7.0.0" />
     <PackageReference Include="BuildBundlerMinifier" Version="2.9.406" Condition="'$(Configuration)'=='Release'" PrivateAssets="All" />
     <PackageReference Include="Microsoft.CodeAnalysis" Version="3.3.1" />
     <PackageReference Include="Microsoft.EntityFrameworkCore.InMemory" Version="3.0.0" />

tests/UnitTests/MediatorHandlers/OrdersTests/GetMyOrders_Should.cs

@@ -0,0 +1,38 @@
+using Microsoft.eShopWeb.ApplicationCore.Entities.OrderAggregate;
+using Microsoft.eShopWeb.ApplicationCore.Interfaces;
+using Microsoft.eShopWeb.Web.Features.MyOrders;
+using Moq;
+using System.Collections.Generic;
+using System.Threading;
+using System.Threading.Tasks;
+using Xunit;
+
+namespace Microsoft.eShopWeb.UnitTests.MediatorHandlers.OrdersTests
+{
+    public class GetMyOrders_Should
+    {
+        private readonly Mock<IOrderRepository> _mockOrderRepository;
+
+        public GetMyOrders_Should()
+        {
+            var item = new OrderItem(new CatalogItemOrdered(1, "ProductName", "URI"), 10.00m, 10);
+            var address = new Address(It.IsAny<string>(), It.IsAny<string>(), It.IsAny<string>(), It.IsAny<string>(), It.IsAny<string>());
+            Order order = new Order("buyerId", address, new List<OrderItem> { item });
+
+            _mockOrderRepository = new Mock<IOrderRepository>();
+            _mockOrderRepository.Setup(x => x.ListAsync(It.IsAny<ISpecification<Order>>())).ReturnsAsync(new List<Order> { order });
+        }
+
+        [Fact]
+        public async Task NotReturnNull_If_OrdersArePresent()
+        {
+            var request = new GetMyOrders("SomeUserName");
+
+            var handler = new GetMyOrdersHandler(_mockOrderRepository.Object);
+
+            var result = await handler.Handle(request, CancellationToken.None);
+
+            Assert.NotNull(result);
+        }
+    }
+}