allow task cancellation

MediatR.EventAggregator/EventAggregator.cs

@@ -5,6 +5,8 @@
 
 namespace MediatR.EventAggregator
 {
+    using System.Threading;
+
     public class EventAggregator : IEventAggregator
     {
         private readonly IMediator mediator;
@@ -24,21 +26,23 @@ public EventAggregator(IMediator mediator)
         }
 
         /// <inheritdoc />
-        public Task PublishAsync<TEvent>(TEvent ev)
+        public Task PublishAsync<TEvent>(TEvent ev, CancellationToken cancellationToken = default(CancellationToken))
             where TEvent : IRequest
         {
             var notification = ev as INotification;
             if (notification != null)
             {
-                this.mediator.Publish(notification);
+                this.mediator.Publish(notification, cancellationToken);
             }
 
             Task sendTask = null;
             var request = ev as IRequest;
             if (request != null)
             {
-                sendTask = this.mediator.Send(request);
+                sendTask = this.mediator.Send(request, cancellationToken);
             }
+
+            cancellationToken.ThrowIfCancellationRequested();
 
             this.HandleCallbacks(ev);
 
@@ -47,10 +51,12 @@ public Task PublishAsync<TEvent>(TEvent ev)
 
         // Note: can we make it more elegant to use , with better type inference ?
         /// <inheritdoc />
-        public Task<TResponse> PublishAsync<TResponse, TEvent>(TEvent ev) 
+        public Task<TResponse> PublishAsync<TResponse, TEvent>(TEvent ev, CancellationToken cancellationToken = default(CancellationToken)) 
             where TEvent : IRequest<TResponse>
         {
-            var sendTask = this.mediator.Send(ev);
+            var sendTask = this.mediator.Send(ev, cancellationToken);
+
+            cancellationToken.ThrowIfCancellationRequested();
 
             this.HandleCallbacks(ev);
 

MediatR.EventAggregator/IEventPublisher.cs

@@ -2,6 +2,8 @@
 
 namespace MediatR.EventAggregator
 {
+    using System.Threading;
+
     /// <summary>
     /// A service providing mechanisms to publish events.
     /// </summary>
@@ -13,7 +15,7 @@ public interface IEventPublisher
         /// <typeparam name="TEvent">The type of the event.</typeparam>
         /// <param name="ev">The event.</param>
         /// <returns>A promise of completion</returns>
-        Task PublishAsync<TEvent>(TEvent ev) where TEvent : IRequest;
+        Task PublishAsync<TEvent>(TEvent ev, CancellationToken cancellationToken = default(CancellationToken)) where TEvent : IRequest;
 
         /// <summary>
         /// Publishes the specified event, expecting an asynchronous response.
@@ -24,6 +26,6 @@ public interface IEventPublisher
         /// <returns>
         /// A promise of a response to the published event.
         /// </returns>
-        Task<TResponse> PublishAsync<TResponse, TEvent>(TEvent ev) where TEvent : IRequest<TResponse>; 
+        Task<TResponse> PublishAsync<TResponse, TEvent>(TEvent ev, CancellationToken cancellationToken = default(CancellationToken)) where TEvent : IRequest<TResponse>; 
     }
 }