Fix #2595: explicit DeliveryOptions.SagaId on saga Start cascades should win

src/Persistence/MartenTests/Bugs/Bug_2595_explicit_delivery_options_sagaid_should_win.cs

@@ -0,0 +1,136 @@
+using IntegrationTests;
+using JasperFx.Core;
+using Marten;
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Hosting;
+using JasperFx.Resources;
+using Shouldly;
+using Wolverine;
+using Wolverine.Marten;
+using Wolverine.Tracking;
+
+namespace MartenTests.Bugs;
+
+/// <summary>
+/// Reproducer for https://github.com/JasperFx/wolverine/issues/2595.
+///
+/// When a saga's static <c>Start</c> method generates its own saga id inside
+/// the method body and cascades a message tagged with an explicit
+/// <c>DeliveryOptions { SagaId = ... }</c>, the explicit value should win over
+/// the inbound envelope's <c>SagaId</c>. Before the fix at
+/// <c>MessageContext.TrackEnvelopeCorrelation</c>, the inbound envelope's
+/// <c>SagaId</c> (or the context's <c>_sagaId</c>) silently overwrote the
+/// explicit value, so a downstream reply that auto-propagates
+/// <c>envelope.SagaId</c> would route back to the wrong saga.
+/// </summary>
+public class Bug_2595_explicit_delivery_options_sagaid_should_win : PostgresqlContext, IAsyncLifetime
+{
+    private IHost _host = null!;
+
+    public async Task InitializeAsync()
+    {
+        _host = await Host.CreateDefaultBuilder()
+            .UseWolverine(opts =>
+            {
+                opts.Services.AddMarten(Servers.PostgresConnectionString)
+                    .IntegrateWithWolverine();
+
+                opts.Services.AddResourceSetupOnStartup();
+
+                opts.Discovery.DisableConventionalDiscovery()
+                    .IncludeType<Bug2595ChildSaga>()
+                    .IncludeType<Bug2595WorkHandler>();
+
+                opts.Policies.AutoApplyTransactions();
+            }).StartAsync();
+    }
+
+    public async Task DisposeAsync()
+    {
+        await _host.StopAsync();
+        _host.Dispose();
+    }
+
+    [Fact]
+    public async Task explicit_delivery_options_sagaid_on_saga_start_cascade_should_win()
+    {
+        // Simulate a parent saga context: send StartChild with an explicit
+        // envelope.SagaId representing some unrelated parent saga's id. The
+        // ChildSaga.Start method will see this on its inbound envelope.
+        var parentSagaId = Guid.NewGuid().ToString();
+
+        var tracked = await _host.TrackActivity()
+            .Timeout(15.Seconds())
+            .SendMessageAndWaitAsync(new Bug2595StartChild(),
+                new DeliveryOptions { SagaId = parentSagaId });
+
+        // The DoWork envelope cascaded out of ChildSaga.Start should carry the
+        // explicit DeliveryOptions.SagaId set by Start (the new ChildSaga.Id),
+        // not the inbound envelope's SagaId.
+        var doWorkEnvelope = tracked.Sent.Envelopes()
+            .Single(e => e.Message is Bug2595DoWork);
+
+        doWorkEnvelope.SagaId.ShouldNotBeNullOrEmpty();
+        doWorkEnvelope.SagaId.ShouldNotBe(parentSagaId,
+            "Saga Start cascades should preserve the explicit DeliveryOptions.SagaId set " +
+            "by the saga's Start method, not be overridden by the inbound envelope's SagaId.");
+
+        var store = _host.Services.GetRequiredService<IDocumentStore>();
+        await using var session = store.LightweightSession();
+
+        // Load the specific child saga that this run produced (the test does
+        // not own its document table; load by id rather than asserting total
+        // table count, so concurrent or prior runs don't break the assertion).
+        var childId = Guid.Parse(doWorkEnvelope.SagaId!);
+        var child = await session.LoadAsync<Bug2595ChildSaga>(childId);
+        child.ShouldNotBeNull("ChildSaga.Start must have inserted the saga document");
+
+        // Final proof: the WorkDone reply auto-propagated the (correct) child
+        // saga id, ChildSaga.Handle(WorkDone) ran, and recorded WorkDone=true
+        // on the child saga document. If the bug were still present the reply
+        // would carry parentSagaId and ChildSaga.Handle(WorkDone) would fail
+        // with UnknownSagaException.
+        child.WorkDone.ShouldBeTrue(
+            "ChildSaga.Handle(WorkDone) should run, proving the explicit SagaId round-tripped.");
+    }
+}
+
+public record Bug2595StartChild;
+
+// Cascaded by ChildSaga.Start with an explicit DeliveryOptions { SagaId = childSagaId }.
+// A plain handler responds with WorkDone; that reply auto-propagates the inbound
+// envelope.SagaId.
+public record Bug2595DoWork(Guid Sentinel);
+
+public record Bug2595WorkDone(Guid Sentinel);
+
+public class Bug2595ChildSaga : Wolverine.Saga
+{
+    public Guid Id { get; set; }
+    public Guid Sentinel { get; set; } = Guid.NewGuid();
+    public bool WorkDone { get; set; }
+
+    public static (Bug2595ChildSaga, OutgoingMessages) Start(Bug2595StartChild _)
+    {
+        var childId = Guid.NewGuid();
+        var sentinel = Guid.NewGuid();
+
+        var outgoing = new OutgoingMessages
+        {
+            // Explicit DeliveryOptions.SagaId — should target the new ChildSaga,
+            // *not* the inbound envelope's SagaId.
+            { new Bug2595DoWork(sentinel), new DeliveryOptions { SagaId = childId.ToString() } }
+        };
+
+        return (new Bug2595ChildSaga { Id = childId, Sentinel = sentinel }, outgoing);
+    }
+
+    public void Handle(Bug2595WorkDone _) => WorkDone = true;
+}
+
+// Plain (non-saga) handler standing in for an external service. Its reply
+// auto-propagates the inbound envelope.SagaId.
+public class Bug2595WorkHandler
+{
+    public static Bug2595WorkDone Handle(Bug2595DoWork message) => new(message.Sentinel);
+}

src/Wolverine/Runtime/MessageContext.cs

@@ -794,7 +794,22 @@ private async Task flushScheduledMessagesAsync()
     internal override void TrackEnvelopeCorrelation(Envelope outbound, Activity? activity)
     {
         base.TrackEnvelopeCorrelation(outbound, activity);
-        outbound.SagaId = _sagaId?.ToString() ?? Envelope?.SagaId ?? outbound.SagaId;
+
+        // Precedence (highest to lowest):
+        //   1. An explicit SagaId set on the outbound envelope by the caller
+        //      (e.g. via DeliveryOptions.SagaId in OutgoingMessages, or set
+        //      directly on the envelope). This must win — a saga's Start
+        //      method that generates its own id and tags a cascaded message
+        //      with it should not have that explicit value silently
+        //      overwritten by the inbound envelope's SagaId or the context's
+        //      _sagaId. See GH-2595.
+        //   2. The current message context's _sagaId — the saga id resolved
+        //      for the message currently being handled (set by saga handler
+        //      generated code or by ReadEnvelope from the inbound envelope).
+        //   3. The inbound envelope's SagaId as a final fallback.
+        outbound.SagaId = outbound.SagaId.IsNotEmpty()
+            ? outbound.SagaId
+            : (_sagaId?.ToString() ?? Envelope?.SagaId);
 
         if (ConversationId != Guid.Empty)
         {