Fix Null Reference Exceptions (#455)

* Fix NullReferenceException Fix NullReferenceException when configuring publishing and subscribing if no IMessageSerialisationFactory is configured. * Add null check for handlers Add null check on handlers. Specify argument name in exception. * Add null check for handler Add a null check on handler.
justeattakeaway · Nov 26, 2018 · b2ab1d0 · b2ab1d0
1 parent 2d09e66
commit b2ab1d0
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Showing 2 changed files with 22 additions and 2 deletions.
diff --git a/JustSaying/JustSayingFluently.cs b/JustSaying/JustSayingFluently.cs
@@ -6,11 +6,11 @@
 using JustSaying.AwsTools.MessageHandling;
 using JustSaying.AwsTools.QueueCreation;
 using JustSaying.Extensions;
+using JustSaying.Messaging.Interrogation;
 using JustSaying.Messaging.MessageHandling;
 using JustSaying.Messaging.MessageSerialisation;
 using JustSaying.Messaging.Monitoring;
 using JustSaying.Models;
-using JustSaying.Messaging.Interrogation;
 using Microsoft.Extensions.Logging;
 
 namespace JustSaying
@@ -232,6 +232,16 @@ public IFluentSubscription IntoQueue(string queuename)
         /// <returns></returns>
         public IHaveFulfilledSubscriptionRequirements WithMessageHandler<T>(IHandlerAsync<T> handler) where T : Message
         {
+            if (handler == null)
+            {
+                throw new ArgumentNullException(nameof(handler));
+            }
+
+            if (_serialisationFactory == null)
+            {
+                throw new InvalidOperationException($"No {nameof(IMessageSerialisationFactory)} has been configured.");
+            }
+
             // TODO - Subscription listeners should be just added once per queue,
             // and not for each message handler
             var thing =  _subscriptionConfig.SubscriptionType == SubscriptionType.PointToPoint
@@ -250,6 +260,11 @@ public IHaveFulfilledSubscriptionRequirements WithMessageHandler<T>(IHandlerAsyn
 
         public IHaveFulfilledSubscriptionRequirements WithMessageHandler<T>(IHandlerResolver handlerResolver) where T : Message
         {
+            if (_serialisationFactory == null)
+            {
+                throw new InvalidOperationException($"No {nameof(IMessageSerialisationFactory)} has been configured.");
+            }
+
             var thing = _subscriptionConfig.SubscriptionType == SubscriptionType.PointToPoint
                 ? PointToPointHandler<T>()
                 : TopicHandler<T>();

diff --git a/JustSaying/JustSayingFluentlyExtensions.cs b/JustSaying/JustSayingFluentlyExtensions.cs
@@ -66,9 +66,14 @@ public static IFluentSubscription IntoDefaultQueue(this ISubscriberIntoQueue sub
         public static IHaveFulfilledSubscriptionRequirements WithMessageHandlers<T>(
              this IFluentSubscription sub, params IHandlerAsync<T>[] handlers) where T : Message
         {
+            if (handlers == null)
+            {
+                throw new ArgumentNullException(nameof(handlers));
+            }
+
             if (handlers.Length == 0)
             {
-                throw new ArgumentException("No handlers in list");
+                throw new ArgumentException("No message handlers specified.", nameof(handlers));
             }
 
             if (handlers.Length == 1)