Better message bus logging

Author: niemyjski

src/Foundatio.TestHarness/Messaging/MessageBusTestBase.cs

@@ -293,7 +293,7 @@ await messageBus.SubscribeAsync<SimpleMessageA>(msg =>
             });
 
             await Parallel.ForEachAsync(Enumerable.Range(1, iterations), async (_, _) => await messageBus.PublishAsync(new SimpleMessageA { Data = "Hello" }));
-            await countdown.WaitAsync(TimeSpan.FromSeconds(2));
+            await countdown.WaitAsync(TimeSpan.FromSeconds(5));
             Assert.Equal(0, countdown.CurrentCount);
         }
         finally

src/Foundatio/Messaging/MessageBusBase.cs

@@ -130,7 +130,10 @@ protected virtual Task SubscribeImplAsync<T>(Func<T, CancellationToken, Task> ha
             {
                 _subscribers.TryRemove(subscriber.Id, out _);
                 if (_subscribers.Count == 0)
+                {
+                    _logger.LogDebug("Removing topic subscription for {MessageBusId}: No subscribers", MessageBusId);
                     RemoveTopicSubscriptionAsync().GetAwaiter().GetResult();
+                }
             });
         }