Fixing the CreateOrderCommand so it is 100% immutable. It shouldn't have the AddOrderItem() method. In any case, it was not really used but in the tets, since this Command is serialized in the client side, then deserialized in the service level.

Author: CESARDELATORRE

src/Services/Ordering/Ordering.API/Application/Commands/CreateOrderCommand.cs

@@ -61,20 +61,16 @@ public class CreateOrderCommand
         [DataMember]
         public IEnumerable<OrderItemDTO> OrderItems => _orderItems;
 
-        public void AddOrderItem(OrderItemDTO item)
-        {
-            _orderItems.Add(item);
-        }
-
         public CreateOrderCommand()
         {
             _orderItems = new List<OrderItemDTO>();
         }
 
-        public CreateOrderCommand(string city, string street, string state, string country, string zipcode,
+        public CreateOrderCommand(List<OrderItemDTO> orderItems, string city, string street, string state, string country, string zipcode,
             string cardNumber, string cardHolderName, DateTime cardExpiration,
             string cardSecurityNumber, int cardTypeId, int paymentId, int buyerId) : this()
         {
+            _orderItems = orderItems;
             City = city;
             Street = street;
             State = state;

test/Services/FunctionalTests/Services/Ordering/OrderingScenarios.cs

@@ -45,7 +45,19 @@ public async Task Create_order_and_return_the_order_by_id()
 
         string BuildOrder()
         {
+            List<OrderItemDTO> orderItemsList = new List<OrderItemDTO>();
+            orderItemsList.Add(new OrderItemDTO()
+                                                    {
+                                                        ProductId = 1,
+                                                        Discount = 8M,
+                                                        UnitPrice = 10,
+                                                        Units = 1,
+                                                        ProductName = "Some name"
+                                                    }
+                               );
+
             var order = new CreateOrderCommand(
+                orderItemsList,
                 cardExpiration: DateTime.UtcNow.AddYears(1),
                 cardNumber: "5145-555-5555",
                 cardHolderName: "Jhon Senna",
@@ -60,15 +72,6 @@ string BuildOrder()
                 buyerId: 3
             );
 
-            order.AddOrderItem(new OrderItemDTO()
-            {
-                ProductId = 1,
-                Discount = 8M,
-                UnitPrice = 10,
-                Units = 1,
-                ProductName = "Some name"
-            });
-
             return JsonConvert.SerializeObject(order);
         }       
     }

test/Services/IntegrationTests/Services/Ordering/OrderingScenarios.cs

@@ -9,7 +9,9 @@
     using System.Text;
     using System.Threading.Tasks;
     using Xunit;
+    using System.Collections;
     using static Microsoft.eShopOnContainers.Services.Ordering.API.Application.Commands.CreateOrderCommand;
+    using System.Collections.Generic;
 
     public class OrderingScenarios
         : OrderingScenarioBase
@@ -59,7 +61,19 @@ public async Task AddNewOrder_response_bad_request_if_card_expiration_is_invalid
 
         string BuildOrder()
         {
+            List<OrderItemDTO> orderItemsList = new List<OrderItemDTO>();
+            orderItemsList.Add(new OrderItemDTO()
+                                                {
+                                                    ProductId = 1,
+                                                    Discount = 10M,
+                                                    UnitPrice = 10,
+                                                    Units = 1,
+                                                    ProductName = "Some name"
+                                                }
+                               );
+
             var order = new CreateOrderCommand(
+                orderItemsList,
                 cardExpiration: DateTime.UtcNow.AddYears(1),
                 cardNumber: "5145-555-5555",
                 cardHolderName: "Jhon Senna",
@@ -74,20 +88,12 @@ string BuildOrder()
                 buyerId: 1               
             );
 
-            order.AddOrderItem(new OrderItemDTO()
-            {
-                ProductId = 1,
-                Discount = 10M,
-                UnitPrice = 10,
-                Units = 1,
-                ProductName = "Some name"
-            });
-
             return JsonConvert.SerializeObject(order);
         }
         string BuildOrderWithInvalidExperationTime()
         {
             var order = new CreateOrderCommand(
+                null,
                 cardExpiration: DateTime.UtcNow.AddYears(-1),
                 cardNumber: "5145-555-5555",
                 cardHolderName: "Jhon Senna",

test/Services/UnitTest/Ordering/Application/IdentifierCommandHandlerTest.cs

@@ -70,6 +70,7 @@ public async Task Handler_sends_no_command_when_order_already_exists()
         private CreateOrderCommand FakeOrderRequest(Dictionary<string, object> args = null)
         {
             return new CreateOrderCommand(
+                null,
                 city: args != null && args.ContainsKey("city") ? (string)args["city"] : null,
                 street: args != null && args.ContainsKey("street") ? (string)args["street"] : null,
                 state: args != null && args.ContainsKey("state") ? (string)args["state"] : null,

test/Services/UnitTest/Ordering/Application/NewOrderCommandHandlerTest.cs

@@ -72,6 +72,7 @@ private Order FakeOrder()
         private CreateOrderCommand FakeOrderRequestWithBuyer(Dictionary<string, object> args = null)
         {
             return new CreateOrderCommand(
+                null,
                 city: args != null && args.ContainsKey("city") ? (string)args["city"] : null,
                 street: args != null && args.ContainsKey("street") ? (string)args["street"] : null,
                 state: args != null && args.ContainsKey("state") ? (string)args["state"] : null,