Refactor to event bus to support dynamic subscriptions to events

Checkout HTTP entrypoint in Basket API

src/BuildingBlocks/EventBus/EventBus/Abstractions/IDynamicIntegrationEventHandler.cs

@@ -0,0 +1,13 @@
+using Microsoft.eShopOnContainers.BuildingBlocks.EventBus.Abstractions;
+using System;
+using System.Collections.Generic;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Microsoft.eShopOnContainers.BuildingBlocks.EventBus.Abstractions
+{
+    public interface IDynamicIntegrationEventHandler
+    {
+        Task Handle(dynamic eventData);
+    }
+}

src/BuildingBlocks/EventBus/EventBus/Abstractions/IEventBus.cs

@@ -8,6 +8,12 @@ namespace Microsoft.eShopOnContainers.BuildingBlocks.EventBus.Abstractions
         void Subscribe<T, TH>(Func<TH> handler)
             where T : IntegrationEvent
             where TH : IIntegrationEventHandler<T>;
+        void SubscribeDynamic<TH>(string eventName, Func<TH> handler)
+            where TH : IDynamicIntegrationEventHandler;
+
+        void UnsubscribeDynamic<TH>(string eventName)
+            where TH : IDynamicIntegrationEventHandler;
+
         void Unsubscribe<T, TH>()
             where TH : IIntegrationEventHandler<T>
             where T : IntegrationEvent;

src/BuildingBlocks/EventBus/EventBus/EventBus.csproj

@@ -6,10 +6,6 @@
     <RootNamespace>Microsoft.eShopOnContainers.BuildingBlocks.EventBus</RootNamespace>
   </PropertyGroup>
 
-  <ItemGroup>
-    <Folder Include="Abstractions\" />
-  </ItemGroup>
-
   <ItemGroup>
     <PackageReference Include="Newtonsoft.Json" Version="9.0.1" />
   </ItemGroup>

src/BuildingBlocks/EventBus/EventBus/IEventBusSubscriptionsManager.cs

@@ -2,6 +2,7 @@
 using Microsoft.eShopOnContainers.BuildingBlocks.EventBus.Events;
 using System;
 using System.Collections.Generic;
+using static Microsoft.eShopOnContainers.BuildingBlocks.EventBus.InMemoryEventBusSubscriptionsManager;
 
 namespace Microsoft.eShopOnContainers.BuildingBlocks.EventBus
 {
@@ -9,18 +10,25 @@ namespace Microsoft.eShopOnContainers.BuildingBlocks.EventBus
     {
         bool IsEmpty { get; }
         event EventHandler<string> OnEventRemoved;
+        void AddDynamicSubscription<TH>(string eventName, Func<TH> handler)
+           where TH : IDynamicIntegrationEventHandler;
+
         void AddSubscription<T, TH>(Func<TH> handler)
            where T : IntegrationEvent
            where TH : IIntegrationEventHandler<T>;
 
-       void RemoveSubscription<T, TH>()
-            where TH : IIntegrationEventHandler<T>
-            where T : IntegrationEvent;
+        void RemoveSubscription<T, TH>()
+             where TH : IIntegrationEventHandler<T>
+             where T : IntegrationEvent;
+        void RemoveDynamicSubscription<TH>(string eventName)
+            where TH : IDynamicIntegrationEventHandler;
+
         bool HasSubscriptionsForEvent<T>() where T : IntegrationEvent;
         bool HasSubscriptionsForEvent(string eventName);
         Type GetEventTypeByName(string eventName);
         void Clear();
-        IEnumerable<Delegate> GetHandlersForEvent<T>() where T : IntegrationEvent;
-        IEnumerable<Delegate> GetHandlersForEvent(string eventName);
+        IEnumerable<SubscriptionInfo> GetHandlersForEvent<T>() where T : IntegrationEvent;
+        IEnumerable<SubscriptionInfo> GetHandlersForEvent(string eventName);
+        string GetEventKey<T>();
     }
 }

src/BuildingBlocks/EventBus/EventBus/InMemoryEventBusSubscriptionsManager.cs

@@ -8,64 +8,99 @@ using System.Text;
 
 namespace Microsoft.eShopOnContainers.BuildingBlocks.EventBus
 {
-    public class InMemoryEventBusSubscriptionsManager : IEventBusSubscriptionsManager
+    public partial class InMemoryEventBusSubscriptionsManager : IEventBusSubscriptionsManager
     {
-        private readonly Dictionary<string, List<Delegate>> _handlers;
+
+
+        private readonly Dictionary<string, List<SubscriptionInfo>> _handlers;
         private readonly List<Type> _eventTypes;
 
         public event EventHandler<string> OnEventRemoved;
 
         public InMemoryEventBusSubscriptionsManager()
         {
-            _handlers = new Dictionary<string, List<Delegate>>();
+            _handlers = new Dictionary<string, List<SubscriptionInfo>>();
             _eventTypes = new List<Type>();
         }
 
         public bool IsEmpty => !_handlers.Keys.Any();
         public void Clear() => _handlers.Clear();
 
-        public void AddSubscription<T, TH>(Func<TH> handler) 
+        public void AddDynamicSubscription<TH>(string eventName, Func<TH> handler)
+            where TH : IDynamicIntegrationEventHandler
+        {
+            DoAddSubscription(handler, eventName, isDynamic: true);
+        }
+
+        public void AddSubscription<T, TH>(Func<TH> handler)
             where T : IntegrationEvent
             where TH : IIntegrationEventHandler<T>
         {
-            var key = GetEventKey<T>();
-            if (!HasSubscriptionsForEvent<T>())
+            var eventName = GetEventKey<T>();
+            DoAddSubscription(handler, eventName, isDynamic: false);
+            _eventTypes.Add(typeof(T));
+        }
+
+        private void DoAddSubscription(Delegate handler, string eventName, bool isDynamic)
+        {
+            if (!HasSubscriptionsForEvent(eventName))
             {
-                _handlers.Add(key, new List<Delegate>());
+                _handlers.Add(eventName, new List<SubscriptionInfo>());
             }
-            _handlers[key].Add(handler);
-            _eventTypes.Add(typeof(T));
+            if (isDynamic)
+            {
+                _handlers[eventName].Add(SubscriptionInfo.Dynamic(handler));
+            }
+            else
+            {
+                _handlers[eventName].Add(SubscriptionInfo.Typed(handler));
+            }
+        }
+
+
+        public void RemoveDynamicSubscription<TH>(string eventName)
+            where TH : IDynamicIntegrationEventHandler
+        {
+            var handlerToRemove = FindDynamicSubscriptionToRemove<TH>(eventName);
+            DoRemoveHandler(eventName, handlerToRemove);
         }
 
+
         public void RemoveSubscription<T, TH>()
             where TH : IIntegrationEventHandler<T>
             where T : IntegrationEvent
         {
-            var handlerToRemove = FindHandlerToRemove<T, TH>();
-            if (handlerToRemove != null)
+            var handlerToRemove = FindSubscriptionToRemove<T, TH>();
+            var eventName = GetEventKey<T>();
+            DoRemoveHandler(eventName, handlerToRemove);
+        }
+
+
+        private void DoRemoveHandler(string eventName, SubscriptionInfo subsToRemove)
+        {
+            if (subsToRemove != null)
             {
-                var key = GetEventKey<T>();
-                _handlers[key].Remove(handlerToRemove);
-                if (!_handlers[key].Any())
+                _handlers[eventName].Remove(subsToRemove);
+                if (!_handlers[eventName].Any())
                 {
-                    _handlers.Remove(key);
-                    var eventType = _eventTypes.SingleOrDefault(e => e.Name == key);
+                    _handlers.Remove(eventName);
+                    var eventType = _eventTypes.SingleOrDefault(e => e.Name == eventName);
                     if (eventType != null)
                     {
                         _eventTypes.Remove(eventType);
-                        RaiseOnEventRemoved(eventType.Name);
                     }
+                    RaiseOnEventRemoved(eventName);
                 }
-                
+
             }
         }
 
-        public IEnumerable<Delegate> GetHandlersForEvent<T>() where T : IntegrationEvent
+        public IEnumerable<SubscriptionInfo> GetHandlersForEvent<T>() where T : IntegrationEvent
         {
             var key = GetEventKey<T>();
             return GetHandlersForEvent(key);
         }
-        public IEnumerable<Delegate> GetHandlersForEvent(string eventName) => _handlers[eventName];
+        public IEnumerable<SubscriptionInfo> GetHandlersForEvent(string eventName) => _handlers[eventName];
 
         private void RaiseOnEventRemoved(string eventName)
         {
@@ -76,22 +111,34 @@ namespace Microsoft.eShopOnContainers.BuildingBlocks.EventBus
             }
         }
 
-        private Delegate FindHandlerToRemove<T, TH>()
-            where T : IntegrationEvent
-            where TH : IIntegrationEventHandler<T>
+
+        private SubscriptionInfo FindDynamicSubscriptionToRemove<TH>(string eventName)
+            where TH : IDynamicIntegrationEventHandler
         {
-            if (!HasSubscriptionsForEvent<T>())
+            return DoFindHandlerToRemove(eventName, typeof(TH));
+        }
+
+
+        private SubscriptionInfo FindSubscriptionToRemove<T, TH>()
+             where T : IntegrationEvent
+             where TH : IIntegrationEventHandler<T>
+        {
+            var eventName = GetEventKey<T>();
+            return DoFindHandlerToRemove(eventName, typeof(TH));
+        }
+
+        private SubscriptionInfo DoFindHandlerToRemove(string eventName, Type handlerType)
+        {
+            if (!HasSubscriptionsForEvent(eventName))
             {
                 return null;
             }
-
-            var key = GetEventKey<T>();
-            foreach (var func in _handlers[key])
+            foreach (var subscription in _handlers[eventName])
             {
-                var genericArgs = func.GetType().GetGenericArguments();
-                if (genericArgs.SingleOrDefault() == typeof(TH))
+                var genericArgs = subscription.Factory.GetType().GetGenericArguments();
+                if (genericArgs.SingleOrDefault() == handlerType)
                 {
-                    return func;
+                    return subscription;
                 }
             }
 
@@ -104,10 +151,10 @@ namespace Microsoft.eShopOnContainers.BuildingBlocks.EventBus
             return HasSubscriptionsForEvent(key);
         }
         public bool HasSubscriptionsForEvent(string eventName) => _handlers.ContainsKey(eventName);
-       
-        public Type GetEventTypeByName(string eventName) => _eventTypes.Single(t => t.Name == eventName);
 
-        private string GetEventKey<T>()
+        public Type GetEventTypeByName(string eventName) => _eventTypes.SingleOrDefault(t => t.Name == eventName);
+
+        public string GetEventKey<T>()
         {
             return typeof(T).Name;
         }

src/BuildingBlocks/EventBus/EventBus/SubscriptionInfo.cs

@@ -0,0 +1,28 @@
+using System;
+
+namespace Microsoft.eShopOnContainers.BuildingBlocks.EventBus
+{
+    public partial class InMemoryEventBusSubscriptionsManager : IEventBusSubscriptionsManager
+    {
+        public class SubscriptionInfo
+        {
+            public bool IsDynamic { get; }
+            public Delegate Factory { get; }
+
+            private SubscriptionInfo(bool isDynamic, Delegate factory)
+            {
+                IsDynamic = isDynamic;
+                Factory = factory;
+            }
+
+            public static SubscriptionInfo Dynamic(Delegate factory)
+            {
+                return new SubscriptionInfo(true, factory);
+            }
+            public static SubscriptionInfo Typed(Delegate factory)
+            {
+                return new SubscriptionInfo(false, factory);
+            }
+        }
+    }
+}

src/BuildingBlocks/EventBus/EventBusRabbitMQ/CommandBusRabbitMQ.cs

@@ -1,4 +1,4 @@
-using Microsoft.eShopOnContainers.BuildingBlocks.CommandBus;
+//using Microsoft.eShopOnContainers.BuildingBlocks.CommandBus;
 using Microsoft.Extensions.Logging;
 using Newtonsoft.Json;
 using Polly;
@@ -12,6 +12,7 @@ using System.Net.Sockets;
 using System.Text;
 using System.Threading.Tasks;
 
+/*
 namespace Microsoft.eShopOnContainers.BuildingBlocks.EventBusRabbitMQ
 {
     public class CommandBusRabbitMQ : ICommandBus, IDisposable
@@ -141,3 +142,4 @@ namespace Microsoft.eShopOnContainers.BuildingBlocks.EventBusRabbitMQ
 
     }
 }
+*/

src/BuildingBlocks/EventBus/EventBusRabbitMQ/EventBusRabbitMQ.cs

@@ -3,6 +3,7 @@ using Microsoft.eShopOnContainers.BuildingBlocks.EventBus.Abstractions;
 using Microsoft.eShopOnContainers.BuildingBlocks.EventBus.Events;
 using Microsoft.Extensions.Logging;
 using Newtonsoft.Json;
+using Newtonsoft.Json.Linq;
 using Polly;
 using Polly.Retry;
 using RabbitMQ.Client;
@@ -96,12 +97,25 @@ namespace Microsoft.eShopOnContainers.BuildingBlocks.EventBusRabbitMQ
             }
         }
 
+        public void SubscribeDynamic<TH>(string eventName, Func<TH> handler)
+            where TH: IDynamicIntegrationEventHandler
+        {
+            DoInternalSubscription(eventName);
+            _subsManager.AddDynamicSubscription<TH>(eventName,handler);
+        }
+
         public void Subscribe<T, TH>(Func<TH> handler)
             where T : IntegrationEvent
             where TH : IIntegrationEventHandler<T>
         {
-            var eventName = typeof(T).Name;
-            var containsKey = _subsManager.HasSubscriptionsForEvent<T>();
+            var eventName = _subsManager.GetEventKey<T>();
+            DoInternalSubscription(eventName);
+            _subsManager.AddSubscription<T, TH>(handler);
+        }
+
+        private void DoInternalSubscription(string eventName)
+        {
+            var containsKey = _subsManager.HasSubscriptionsForEvent(eventName);
             if (!containsKey)
             {
                 if (!_persistentConnection.IsConnected)
@@ -116,9 +130,6 @@ namespace Microsoft.eShopOnContainers.BuildingBlocks.EventBusRabbitMQ
                                       routingKey: eventName);
                 }
             }
-
-            _subsManager.AddSubscription<T, TH>(handler);
-
         }
 
         public void Unsubscribe<T, TH>()
@@ -128,19 +139,13 @@ namespace Microsoft.eShopOnContainers.BuildingBlocks.EventBusRabbitMQ
             _subsManager.RemoveSubscription<T, TH>();
         }
 
-        private static Func<IIntegrationEventHandler> FindHandlerByType(Type handlerType, IEnumerable<Func<IIntegrationEventHandler>> handlers)
+        public void UnsubscribeDynamic<TH>(string eventName)
+            where TH: IDynamicIntegrationEventHandler
         {
-            foreach (var func in handlers)
-            {
-                if (func.GetMethodInfo().ReturnType == handlerType)
-                {
-                    return func;
-                }
-            }
-
-            return null;
+            _subsManager.RemoveDynamicSubscription<TH>(eventName);
         }
 
+
         public void Dispose()
         {
             if (_consumerChannel != null)
@@ -191,16 +196,25 @@ namespace Microsoft.eShopOnContainers.BuildingBlocks.EventBusRabbitMQ
         {
 
             if (_subsManager.HasSubscriptionsForEvent(eventName))
-            { 
-                var eventType = _subsManager.GetEventTypeByName(eventName);
-                var integrationEvent = JsonConvert.DeserializeObject(message, eventType);
-                var handlers = _subsManager.GetHandlersForEvent(eventName);
+            {
+                var subscriptions = _subsManager.GetHandlersForEvent(eventName);
 
-                foreach (var handlerfactory in handlers)
+                foreach (var subscription in subscriptions)
                 {
-                    var handler = handlerfactory.DynamicInvoke();
-                    var concreteType = typeof(IIntegrationEventHandler<>).MakeGenericType(eventType);
-                    await (Task)concreteType.GetMethod("Handle").Invoke(handler, new object[] { integrationEvent });
+                    if (subscription.IsDynamic)
+                    {
+                        var handler = subscription.Factory.DynamicInvoke() as IDynamicIntegrationEventHandler;
+                        dynamic eventData = JObject.Parse(message);
+                        await handler.Handle(eventData);
+                    }
+                    else
+                    {
+                        var eventType = _subsManager.GetEventTypeByName(eventName);
+                        var integrationEvent = JsonConvert.DeserializeObject(message, eventType);
+                        var handler = subscription.Factory.DynamicInvoke();
+                        var concreteType = typeof(IIntegrationEventHandler<>).MakeGenericType(eventType);
+                        await (Task)concreteType.GetMethod("Handle").Invoke(handler, new object[] { integrationEvent });
+                    }
                 }
             }
         }

src/Services/Basket/Basket.API/Controllers/BasketController.cs

@@ -5,6 +5,10 @@ using System.Threading.Tasks;
 using Microsoft.AspNetCore.Mvc;
 using Microsoft.eShopOnContainers.Services.Basket.API.Model;
 using Microsoft.AspNetCore.Authorization;
+using Microsoft.AspNetCore.Http;
+using Microsoft.eShopOnContainers.BuildingBlocks.EventBus.Abstractions;
+using Basket.API.IntegrationEvents.Events;
+using Microsoft.eShopOnContainers.Services.Basket.API.Services;
 
 namespace Microsoft.eShopOnContainers.Services.Basket.API.Controllers
 {
@@ -16,11 +20,17 @@ namespace Microsoft.eShopOnContainers.Services.Basket.API.Controllers
     [Authorize]
     public class BasketController : Controller
     {
-        private IBasketRepository _repository;
+        private readonly IBasketRepository _repository;
+        private readonly IIdentityService _identitySvc;
+        private readonly IEventBus _eventBus;
 
-        public BasketController(IBasketRepository repository)
+        public BasketController(IBasketRepository repository, 
+            IIdentityService identityService,
+            IEventBus eventBus)
         {
             _repository = repository;
+            _identitySvc = identityService;
+            _eventBus = eventBus;
         }
         // GET api/values/5
         [HttpGet("{id}")]
@@ -40,11 +50,28 @@ namespace Microsoft.eShopOnContainers.Services.Basket.API.Controllers
             return Ok(basket);
         }
 
+        [HttpPost]
+        public async Task<IActionResult> Checkout()
+        {
+            var userId = _identitySvc.GetUserIdentity();
+            var basket = await _repository.GetBasketAsync(userId);
+            _eventBus.Publish(new UserCheckoutAccepted(userId, basket));
+            if (basket == null)
+            {
+                return BadRequest();
+            }
+
+
+
+            return Accepted();
+        }
+
         // DELETE api/values/5
         [HttpDelete("{id}")]
         public void Delete(string id)
         {
             _repository.DeleteBasketAsync(id);
         }
+
     }
 }

src/Services/Basket/Basket.API/IntegrationEvents/Events/UserCheckoutAccepted.cs

@@ -0,0 +1,21 @@
+using Microsoft.eShopOnContainers.BuildingBlocks.EventBus.Events;
+using Microsoft.eShopOnContainers.Services.Basket.API.Model;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading.Tasks;
+
+namespace Basket.API.IntegrationEvents.Events
+{
+    public class UserCheckoutAccepted : IntegrationEvent
+    {
+        public string UserId {get; }
+        CustomerBasket Basket { get; }
+        public UserCheckoutAccepted(string userId, CustomerBasket basket)
+        {
+            UserId = userId;
+            Basket = basket;
+        }
+
+    }
+}

src/Services/Basket/Basket.API/Model/Basket.cs

@@ -13,7 +13,7 @@ namespace Microsoft.eShopOnContainers.Services.Basket.API.Model
         public CustomerBasket(string customerId)
         {
             BuyerId = customerId;
-            Items = new List<Model.BasketItem>();
+            Items = new List<BasketItem>();
         }
     }
 }

src/Services/Basket/Basket.API/Services/IIdentityService.cs

@@ -0,0 +1,12 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading.Tasks;
+
+namespace Microsoft.eShopOnContainers.Services.Basket.API.Services
+{
+    public interface IIdentityService
+    {
+        string GetUserIdentity();
+    }
+}

src/Services/Basket/Basket.API/Services/IdentityService.cs

@@ -0,0 +1,24 @@
+
+using Microsoft.AspNetCore.Http;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading.Tasks;
+
+namespace Microsoft.eShopOnContainers.Services.Basket.API.Services
+{
+    public class IdentityService : IIdentityService
+    {
+        private IHttpContextAccessor _context; 
+
+        public IdentityService(IHttpContextAccessor context)
+        {
+            _context = context ?? throw new ArgumentNullException(nameof(context));
+        }
+
+        public string GetUserIdentity()
+        {
+            return _context.HttpContext.User.FindFirst("sub").Value;
+        }
+    }
+}

src/Services/Ordering/Ordering.API/Application/IntegrationEvents/EventHandling/UserCheckoutAcceptedIntegrationEventHandler.cs

@@ -0,0 +1,16 @@
+using Microsoft.eShopOnContainers.BuildingBlocks.EventBus.Abstractions;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading.Tasks;
+
+namespace Ordering.API.Application.IntegrationEvents.EventHandling
+{
+    public class UserCheckoutAcceptedIntegrationEventHandler : IDynamicIntegrationEventHandler
+    {
+        public async Task Handle(dynamic eventData)
+        {
+            int i = 0;
+        }
+    }
+}

src/Services/Ordering/Ordering.API/Ordering.API.csproj

@@ -80,7 +80,6 @@
 
   <ItemGroup>
     <Folder Include="Application\IntegrationCommands\CommandHandlers\" />
-    <Folder Include="Application\IntegrationEvents\EventHandling\" />
     <Folder Include="Infrastructure\IntegrationEventMigrations\" />
   </ItemGroup>
 

src/Services/Ordering/Ordering.API/Startup.cs

@@ -4,6 +4,7 @@
     using Autofac;
     using Autofac.Extensions.DependencyInjection;
     using global::Ordering.API.Application.IntegrationEvents;
+    using global::Ordering.API.Application.IntegrationEvents.EventHandling;
     using global::Ordering.API.Infrastructure.Middlewares;
     using Infrastructure;
     using Infrastructure.Auth;
@@ -120,9 +121,10 @@
                 return new DefaultRabbitMQPersistentConnection(factory, logger);
             });
 
+
             services.AddSingleton<IEventBusSubscriptionsManager, InMemoryEventBusSubscriptionsManager>();
             services.AddSingleton<IEventBus, EventBusRabbitMQ>();
-
+            services.AddTransient<UserCheckoutAcceptedIntegrationEventHandler>();
             services.AddOptions();
 
             //configure autofac
@@ -136,6 +138,7 @@
             return new AutofacServiceProvider(container.Build());
         }
 
+
         public void Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerFactory)
         {
             loggerFactory.AddConsole(Configuration.GetSection("Logging"));
@@ -146,6 +149,7 @@
             app.UseFailingMiddleware();
 
             ConfigureAuth(app);
+            ConfigureEventBus(app);
 
             app.UseMvcWithDefaultRoute();
 
@@ -161,6 +165,15 @@
             integrationEventLogContext.Database.Migrate();
         }
 
+        private void ConfigureEventBus(IApplicationBuilder app)
+        {
+            var eventBus = app.ApplicationServices.GetRequiredService<IEventBus>();
+            eventBus.SubscribeDynamic(
+                "UserCheckoutAccepted",
+                () => app.ApplicationServices.GetRequiredService<UserCheckoutAcceptedIntegrationEventHandler>());
+
+        }
+
         protected virtual void ConfigureAuth(IApplicationBuilder app)
         {
             var identityUrl = Configuration.GetValue<string>("IdentityUrl");

test/Services/UnitTest/Basket/Application/BasketWebApiTest.cs

@@ -1,20 +1,27 @@
-using Microsoft.AspNetCore.Mvc;
+using Basket.API.IntegrationEvents.Events;
+using Microsoft.AspNetCore.Mvc;
+using Microsoft.eShopOnContainers.BuildingBlocks.EventBus.Abstractions;
 using Microsoft.eShopOnContainers.Services.Basket.API.Controllers;
 using Microsoft.eShopOnContainers.Services.Basket.API.Model;
 using Moq;
 using System.Collections.Generic;
 using System.Threading.Tasks;
 using Xunit;
+using IBasketIdentityService = Microsoft.eShopOnContainers.Services.Basket.API.Services.IIdentityService;
 
 namespace UnitTest.Basket.Application
 {
     public class BasketWebApiTest
     {
         private readonly Mock<IBasketRepository> _basketRepositoryMock;
+        private readonly Mock<IBasketIdentityService> _identityServiceMock;
+        private readonly Mock<IEventBus> _serviceBusMock;
 
         public BasketWebApiTest()
         {
             _basketRepositoryMock = new Mock<IBasketRepository>();
+            _identityServiceMock = new Mock<IBasketIdentityService>();
+            _serviceBusMock = new Mock<IEventBus>();
         }
 
         [Fact]
@@ -26,9 +33,12 @@ namespace UnitTest.Basket.Application
 
             _basketRepositoryMock.Setup(x => x.GetBasketAsync(It.IsAny<string>()))
                 .Returns(Task.FromResult(fakeCustomerBasket));
+            _identityServiceMock.Setup(x => x.GetUserIdentity()).Returns(fakeCustomerId);
 
+            _serviceBusMock.Setup(x => x.Publish(It.IsAny<UserCheckoutAccepted>()));
             //Act
-            var basketController = new BasketController(_basketRepositoryMock.Object);
+            var basketController = new BasketController(
+                _basketRepositoryMock.Object, _identityServiceMock.Object, _serviceBusMock.Object);
             var actionResult = await basketController.Get(fakeCustomerId) as OkObjectResult;
 
             //Assert
@@ -45,9 +55,12 @@ namespace UnitTest.Basket.Application
 
             _basketRepositoryMock.Setup(x => x.UpdateBasketAsync(It.IsAny<CustomerBasket>()))
                 .Returns(Task.FromResult(fakeCustomerBasket));
-
+            _identityServiceMock.Setup(x => x.GetUserIdentity()).Returns(fakeCustomerId);
+            _serviceBusMock.Setup(x => x.Publish(It.IsAny<UserCheckoutAccepted>()));
             //Act
-            var basketController = new BasketController(_basketRepositoryMock.Object);
+            var basketController = new BasketController(
+                _basketRepositoryMock.Object, _identityServiceMock.Object, _serviceBusMock.Object);
+
             var actionResult = await basketController.Post(fakeCustomerBasket) as OkObjectResult;
 
             //Assert
@@ -55,6 +68,38 @@ namespace UnitTest.Basket.Application
             Assert.Equal(((CustomerBasket)actionResult.Value).BuyerId, fakeCustomerId);
         }        
 
+        [Fact]
+        public async Task Doing_Checkout_Without_Basket_Should_Return_Bad_Request()
+        {
+            var fakeCustomerId = "2";
+            _basketRepositoryMock.Setup(x => x.GetBasketAsync(It.IsAny<string>()))
+                .Returns(Task.FromResult((CustomerBasket)null));
+            _identityServiceMock.Setup(x => x.GetUserIdentity()).Returns(fakeCustomerId);
+            //Act
+            var basketController = new BasketController(
+                _basketRepositoryMock.Object, _identityServiceMock.Object, _serviceBusMock.Object);
+
+            var result = await basketController.Checkout() as BadRequestResult;
+            Assert.NotNull(result);
+        }
+
+        [Fact]
+        public async Task Doing_Checkout_Wit_Basket_Should_Publish_UserCheckoutAccepted_Integration_Event()
+        {
+            var fakeCustomerId = "1";
+            var fakeCustomerBasket = GetCustomerBasketFake(fakeCustomerId);
+            _basketRepositoryMock.Setup(x => x.GetBasketAsync(It.IsAny<string>()))
+                 .Returns(Task.FromResult(fakeCustomerBasket));
+            _identityServiceMock.Setup(x => x.GetUserIdentity()).Returns(fakeCustomerId);
+            //Act
+            var basketController = new BasketController(
+                _basketRepositoryMock.Object, _identityServiceMock.Object, _serviceBusMock.Object);
+
+            var result = await basketController.Checkout() as AcceptedResult;
+            _serviceBusMock.Verify(mock => mock.Publish(It.IsAny<UserCheckoutAccepted>()), Times.Once);
+            Assert.NotNull(result);
+        }
+
         private CustomerBasket GetCustomerBasketFake(string fakeCustomerId)
         {            
             return new CustomerBasket(fakeCustomerId)

test/Services/UnitTest/UnitTest.csproj

@@ -13,6 +13,7 @@
   </PropertyGroup>
 
   <ItemGroup>
+    <ProjectReference Include="..\..\..\src\BuildingBlocks\EventBus\EventBus\EventBus.csproj" />
     <ProjectReference Include="..\..\..\src\Services\Basket\Basket.API\Basket.API.csproj" />
     <ProjectReference Include="..\..\..\src\Services\Catalog\Catalog.API\Catalog.API.csproj" />
     <ProjectReference Include="..\..\..\src\Services\Ordering\Ordering.API\Ordering.API.csproj" />