Changed the behavior of InvokeAsync<T>() such that the T is NOT sent …

…as a cascading message and only as the response. Closes GH-1024

docs/guide/messaging/message-bus.md

@@ -87,6 +87,12 @@ case, Wolverine does enforce timeout conditions with a default of 5 seconds whic
 
 ## Request/Reply
 
+::: warning
+There was a breaking change in behavior for this functionality in Wolverine 3.0. The response type, the `T` in `InvokeAsync<T>()` is **not**
+sent as a cascaded message if that type is the requested response type. You will have to explicitly send the response out through `IMessageBus.PublishAsync()`
+to force that to be sent out instead of just being the response.
+:::
+
 Wolverine also has direct support for the [request/reply](https://www.enterpriseintegrationpatterns.com/RequestReply.html) pattern or really just mediating between your code and complex query handlers through
 the `IMessageBus.InvokeAsync<T>()` API. To make that concrete, let's assume you want to request the results of a mathematical operation as shown below
 in these message types and a corresponding message handler:
@@ -127,6 +133,10 @@ public async Task invoke_math_operations(IMessageBus bus)
 Note that this API hides whether or not this operation is a local operation running on the same thread and invoking a local message handler or sending a message through to a remote
 endpoint and waiting for the response. The same timeout mechanics and performance concerns apply to this operation as the `InvokeAsync()` method described in the previous section.
 
+Note that if you execute the `Numbers` message from above with `InvokeAsync<Results>()`, the `Results` response will only be
+returned as the response and will not be published as a message. This was a breaking change in Wolverine 3.0. We think (hope)
+that this will be less confusing.
+
 ## Sending or Publishing Messages
 
 [Publish/Subscribe](https://docs.microsoft.com/en-us/azure/architecture/patterns/publisher-subscriber) is a messaging pattern where the senders of messages do not need to specifically know what the specific subscribers are for a given message. In this case, some kind of middleware or infrastructure is responsible for either allowing subscribers to express interest in what messages they need to receive or apply routing rules to send the published messages to the right places. Wolverine's messaging support was largely built to support the publish/subscribe messaging pattern.

docs/guide/migration.md

@@ -47,3 +47,7 @@ builder.Services.AddWolverineHttp();
 <!-- endSnippet -->
 
 Also for Wolverine.Http users, the `[Document]` attribute behavior in the Marten integration is now "required by default."
+
+The behavior of `IMessageBus.InvokeAsync<T>(message)` changed in 3.0 such that the `T` response **is not also published as a 
+message** at the same time when the initial message is sent with request/response semantics. Wolverine has gone back and forth
+in this behavior in its life, but at this point, the Wolverine thinks that this is the least confusing behavioral rule. 

src/Testing/CoreTests/Acceptance/local_invoke_also_publishes_the_return_value.cs → src/Testing/CoreTests/Acceptance/local_invoke_does_not_publish_the_return_value.cs

@@ -5,10 +5,10 @@
 
 namespace CoreTests.Acceptance;
 
-public class local_invoke_also_publishes_the_return_value
+public class local_invoke_does_not_publish_the_return_value
 {
     [Fact]
-    public async Task should_also_publish_the_return_value_when_invoking_locally()
+    public async Task should_not_publish_the_return_value_when_invoking_locally()
     {
         using var host = await Host.CreateDefaultBuilder()
             .UseWolverine().StartAsync();
@@ -18,11 +18,7 @@ public async Task should_also_publish_the_return_value_when_invoking_locally()
 
         response.Name.ShouldBe(name);
 
-        tracked.Sent.SingleMessage<CommandInvoked>()
-            .Name.ShouldBe(name);
-
-        tracked.Sent.SingleMessage<Message1>().Id.ShouldBe(response.Id);
-        tracked.Sent.SingleMessage<Message2>().Id.ShouldBe(response.Id);
+        tracked.Sent.MessagesOf<CommandInvoked>().Any().ShouldBeFalse();
     }
 }
 

src/Wolverine/Runtime/Handlers/Executor.cs

@@ -122,7 +122,8 @@ public async Task<T> InvokeAsync<T>(object message, MessageBus bus, Cancellation
             ReplyUri = TransportConstants.RepliesUri,
             ReplyRequested = typeof(T).ToMessageTypeName(),
             ResponseType = typeof(T),
-            TenantId = tenantId ?? bus.TenantId
+            TenantId = tenantId ?? bus.TenantId,
+            DoNotCascadeResponse = true
         };
 
         bus.TrackEnvelopeCorrelation(envelope, Activity.Current);

src/Wolverine/Runtime/MessageContext.cs

@@ -362,7 +362,7 @@ public async Task EnqueueCascadingAsync(object? message)
         }
 
         if (Envelope?.ResponseType != null && (message?.GetType() == Envelope.ResponseType ||
-                                               Envelope.ResponseType.IsAssignableFrom(message?.GetType())))
+                                               Envelope.ResponseType.IsInstanceOfType(message)))
         {
             Envelope.Response = message;