Collect all exceptions caught in EndpointResolverExtensions.SelectOne and rethrow them as an AggregateException. Fixes #376.

Author: Sebastian Redl

projects/client/RabbitMQ.Client/src/client/api/IEndpointResolverExtensions.cs

@@ -49,7 +49,7 @@ public static class EndpointResolverExtensions
         public static T SelectOne<T>(this IEndpointResolver resolver, Func<AmqpTcpEndpoint, T> selector)
         {
             var t = default(T);
-            Exception exception = null;
+            var exceptions = new List<Exception>();
             foreach(var ep in resolver.All())
             {
                 try
@@ -62,13 +62,13 @@ public static T SelectOne<T>(this IEndpointResolver resolver, Func<AmqpTcpEndpoi
                 }
                 catch (Exception e)
                 {
-                    exception = e;
+                    exceptions.Add(e);
                 }
             }
 
-            if(Object.Equals(t, default(T)) && exception != null)
+            if(Object.Equals(t, default(T)) && exceptions.Count > 0)
             {
-                throw exception;
+                throw new AggregateException(exceptions);
             }
 
             return t;

projects/client/RabbitMQ.Client/src/client/exceptions/BrokerUnreachableException.cs

@@ -47,8 +47,8 @@ namespace RabbitMQ.Client.Exceptions
     ///ConnectionFactory.CreateConnection attempt.</summary>
     public class BrokerUnreachableException : IOException
     {
-        ///<summary>Construct a BrokerUnreachableException. The inner exception is associated
-        ///with only one connection attempt.</summary>
+        ///<summary>Construct a BrokerUnreachableException. The inner exception is
+        ///an AggregateException holding the errors from multiple connection attempts.</summary>
         public BrokerUnreachableException(Exception Inner)
             : base("None of the specified endpoints were reachable", Inner)
         {

projects/client/Unit/src/unit/TestIEndpointResolverExtensions.cs

@@ -79,7 +79,8 @@ public void SelectOneShouldReturnDefaultWhenThereAreNoEndpoints()
         public void SelectOneShouldRaiseThrownExceptionWhenThereAreOnlyInaccessibleEndpoints()
         {
             var ep = new TestEndpointResolver(new List<AmqpTcpEndpoint> { new AmqpTcpEndpoint()});
-            Assert.Throws<TestEndpointException>(() => ep.SelectOne<AmqpTcpEndpoint>((x) => { throw new TestEndpointException("bananas"); }));
+            var thrown = Assert.Throws<AggregateException>(() => ep.SelectOne<AmqpTcpEndpoint>((x) => { throw new TestEndpointException("bananas"); }));
+            Assert.That(thrown.InnerExceptions, Has.Exactly(1).TypeOf<TestEndpointException>());
         }
 
         [Test]