fix(vtags): prune _planByVtag on child termination + crash-then-change test (H1b review follow-up)

2026-06-15 10:12:11 -04:00
parent ada01e1af8
commit ebf2f1dd7a
2 changed files with 42 additions and 4 deletions
@@ -243,6 +243,40 @@ public sealed class VirtualTagHostActorTests : RuntimeActorTestBase
        mux.ExpectNoMsg(TimeSpan.FromMilliseconds(400));
    }

+    /// <summary>
+    /// H1b crash-then-change: after a child terminates unexpectedly AND the next apply carries a
+    /// CHANGED plan for the same vtagId, the replacement child must adopt the NEW plan (refs "B"),
+    /// not the stale one (refs "A"). This pins that OnChildTerminated prunes _planByVtag so the
+    /// change-detect guard can't be confused by a dead child's old plan.
+    /// </summary>
+    [Fact]
+    public void Respawn_after_termination_with_a_changed_plan_adopts_the_new_refs()
+    {
+        var publish = CreateTestProbe();
+        var mux = CreateTestProbe();
+        var host = Sys.ActorOf(VirtualTagHostActor.Props(publish.Ref, mux.Ref, new StubEvaluator()));
+
+        // First apply — child registers interest in "A".
+        host.Tell(new VirtualTagHostActor.ApplyVirtualTags(
+            new[] { PlanWithRefs("vt-1", "eq-1", "speed-rpm", "ctx.GetTag(\"A\")", "A") }));
+        mux.ExpectMsg<DependencyMuxActor.RegisterInterest>().TagRefs.ShouldContain("A");
+        var firstChild = mux.LastSender;
+
+        // Kill the child deterministically and drain its PostStop UnregisterInterest.
+        Watch(firstChild);
+        Sys.Stop(firstChild);
+        ExpectTerminated(firstChild);
+        mux.ExpectMsg<DependencyMuxActor.UnregisterInterest>(TimeSpan.FromSeconds(5));
+
+        // Re-apply with a CHANGED plan (refs "B"). The replacement must register the NEW refs.
+        host.Tell(new VirtualTagHostActor.ApplyVirtualTags(
+            new[] { PlanWithRefs("vt-1", "eq-1", "speed-rpm", "ctx.GetTag(\"B\")", "B") }));
+        var reg2 = mux.ExpectMsg<DependencyMuxActor.RegisterInterest>(TimeSpan.FromSeconds(5));
+        reg2.TagRefs.ShouldContain("B");
+        reg2.TagRefs.ShouldNotContain("A");
+        mux.LastSender.ShouldNotBe(firstChild);
+    }
+
    /// <summary>Deterministic no-op evaluator: keeps spawned children inert so tests drive the host's
    /// OnResult path directly via synthetic EvaluationResults.</summary>
    private sealed class StubEvaluator : IVirtualTagEvaluator