Ability to use messages to sagas even when the message is also handled by separate handlers otherwise.

Author: jeremydmiller

docs/guide/handlers/index.md

@@ -165,8 +165,9 @@ would use those values.
 Pay attention to this section if you are trying to utilize a "Modular Monolith" architecture.
 :::
 
-::: warning
-The `Separated` setting is ignored by `Saga` handlers
+::: info
+The `Separated` setting is useful even with `Saga` handlers as of Wolverine 5.10, but ignored
+in previous versions.
 :::
 
 Let's say that you want to take more than one action on a message type published in or to your

src/Testing/CoreTests/Persistence/Sagas/using_a_saga_with_separated_behavior_mode.cs

@@ -0,0 +1,64 @@
+using System.Diagnostics;
+using JasperFx.Core;
+using Microsoft.Extensions.Hosting;
+using Wolverine.Attributes;
+using Wolverine.Tracking;
+using Xunit;
+
+namespace CoreTests.Persistence.Sagas;
+
+public class using_a_saga_with_separated_behavior_mode
+{
+    [Fact]
+    public async Task able_to_use_separated_behaviors_with_sagas()
+    {
+        using var host = await Host.CreateDefaultBuilder()
+            .UseWolverine(opts =>
+            {
+                opts.Discovery.DisableConventionalDiscovery()
+                    .IncludeType(typeof(TrackedThing))
+                    .IncludeType(typeof(OtherThingUpdatedHandler));
+                
+                opts.MultipleHandlerBehavior = MultipleHandlerBehavior.Separated;
+            }).StartAsync();
+
+        var id = Guid.NewGuid();
+
+        await host.InvokeMessageAndWaitAsync(new StartTracking(id));
+
+        var tracked = await host.SendMessageAndWaitAsync(new ThingUpdated(id));
+        var envelopes = tracked.Executed.Envelopes().Where(x => x.Message is ThingUpdated).ToArray();
+        envelopes.Length.ShouldBe(2);
+
+        envelopes.Any(x => x.Destination == new Uri("local://coretests.persistence.sagas.trackedthing/")).ShouldBeTrue();
+        envelopes.Any(x => x.Destination == new Uri("local://coretests.persistence.sagas.otherthingupdatedhandler/")).ShouldBeTrue();
+    }
+}
+
+public record StartTracking(Guid Id);
+
+public record ThingUpdated(Guid Id);
+
+public class TrackedThing : Saga
+{
+    public Guid Id { get; set; }
+    
+    public int Updates { get; set; }
+
+    public static TrackedThing Start(StartTracking cmd) => new TrackedThing { Id = cmd.Id };
+
+    public void Handle(ThingUpdated updated, Envelope envelope)
+    {
+        Updates++;
+        Debug.WriteLine(envelope.Destination);
+    }
+}
+
+[WolverineIgnore]
+public static class OtherThingUpdatedHandler
+{
+    public static void Handle(ThingUpdated updated)
+    {
+        Debug.WriteLine("Got updated for " + updated.Id);
+    }
+}

src/Wolverine/Persistence/Sagas/SagaChain.cs

@@ -1,10 +1,12 @@
+using System.Diagnostics;
 using JasperFx;
 using JasperFx.CodeGeneration;
 using JasperFx.CodeGeneration.Frames;
 using JasperFx.CodeGeneration.Model;
 using JasperFx.Core;
 using JasperFx.Core.Reflection;
 using System.Reflection;
+using Wolverine.Configuration;
 using Wolverine.Logging;
 using Wolverine.Runtime.Handlers;
 
@@ -51,6 +53,25 @@ public SagaChain(WolverineOptions options, IGrouping<Type, HandlerCall> grouping
         }
     }
 
+    public SagaChain(HandlerCall handlerCall, HandlerGraph handlerGraph, Endpoint[] endpoints) : base(handlerCall, handlerGraph)
+    {
+        foreach (var endpoint in endpoints) RegisterEndpoint(endpoint);
+        
+        var saga = handlerCall;
+        SagaType = saga.HandlerType;
+        SagaMethodInfo = saga.Method;
+        
+        Handlers.Add(handlerCall);
+
+        SagaIdMember = DetermineSagaIdMember(MessageType, SagaType, saga.Method);
+
+        // Automatically audit the saga id
+        if (SagaIdMember != null && AuditedMembers.All(x => x.Member != SagaIdMember))
+        {
+            AuditedMembers.Add(new AuditedMember(SagaIdMember, SagaIdMember.Name, SagaIdMember.Name));
+        }
+    }
+
     public override bool TryInferMessageIdentity(out PropertyInfo? property)
     {
         property = SagaIdMember as PropertyInfo;
@@ -62,11 +83,6 @@ protected override void validateAgainstInvalidSagaMethods(IGrouping<Type, Handle
         // Nothing
     }
 
-    protected override void tryAssignStickyEndpoints(HandlerCall handlerCall, WolverineOptions options)
-    {
-        // nope, don't do this with saga chains 
-    }
-
     public Type SagaType { get; }
 
     public MethodInfo? SagaMethodInfo { get; set; }

src/Wolverine/Runtime/Handlers/HandlerChain.cs

@@ -70,7 +70,7 @@ public HandlerChain(Type messageType, HandlerGraph parent)
         applyAuditAttributes(messageType);
     }
 
-    private HandlerChain(MethodCall call, HandlerGraph parent) : this(call.Method.MessageType()!, parent)
+    protected HandlerChain(MethodCall call, HandlerGraph parent) : this(call.Method.MessageType()!, parent)
     {
         Handlers.Add(call);
     }
@@ -284,15 +284,16 @@ bool ICodeFile.AttachTypesSynchronously(GenerationRules rules, Assembly assembly
     /// </summary>
     public FailureRuleCollection Failures { get; } = new();
 
-    protected virtual void tryAssignStickyEndpoints(HandlerCall handlerCall, WolverineOptions options)
+    protected void tryAssignStickyEndpoints(HandlerCall handlerCall, WolverineOptions options)
     {
         var endpoints = findStickyEndpoints(handlerCall, options).Distinct().ToArray();
         if (endpoints.Any())
         {
             foreach (var stub in endpoints.OfType<StubEndpoint>())
                 stub.Subscriptions.Add(Subscription.ForType(MessageType));
 
-            var chain = new HandlerChain(handlerCall, options.HandlerGraph, endpoints);
+            var chain = handlerCall.HandlerType.CanBeCastTo<Saga>() ? new SagaChain(handlerCall,
+                options.HandlerGraph, endpoints) : new HandlerChain(handlerCall, options.HandlerGraph, endpoints);
 
             Handlers.Remove(handlerCall);
 

src/Wolverine/Runtime/Handlers/HandlerGraph.cs

@@ -319,6 +319,7 @@ IEnumerable<HandlerChain> explodeChains(HandlerChain chain)
 
         // This lovely thing was brought to you by https://github.com/JasperFx/wolverine/issues/2004
         var duplicateTypeNames = allChains
+            .Where(x => x.Handlers.Any()) // filter out the parent, placeholder HandlerChain for separated handlers
             .GroupBy(x => x.TypeName)
             .Where(x => x.Count() > 1)
             .ToArray();