Give a work-queue stream its one consumer, drop-only dead letters (issue 1178)

internal/inventory/busrecords.go

@@ -187,6 +187,9 @@ func declaredFor(m catalogue.Manifest, seats map[string]catalogue.SeatDeclaratio
 		Logs: logsOf(m),
 		// And the streams it owns (novox/hq ADR 0363).
 		Streams: streamsOf(m),
+		// And its own work-queue streams, each with the one process its bus.queues names as the
+		// consumer (novox/hq ADR 0436 §1, §2, §6).
+		Queues: queueOwnersOf(m),
 		// And the tools its health asks (novox/hq ADR 0240): the machine's node-engine is granted them.
 		Checks: catalogue.HealthChecks(m),
 		// And whether it runs as an account of its own (novox/hq ADR 0259 §8).
@@ -428,6 +431,37 @@ func streamsOf(m catalogue.Manifest) []broker.ModuleStream {
 	return out
 }
 
+// queueOwnersOf is every work-queue stream of a module's own that one of its processes names in bus.queues,
+// with that process's id and the stream's declared max-deliveries (novox/hq ADR 0436 §1, §2, §6). In
+// resource order, so composition is repeatable; a queue naming a stream the module does not own, or one two
+// processes name, is caught at registration (catalogue.WorkQueueStreamProblems) and never reaches here.
+func queueOwnersOf(m catalogue.Manifest) []broker.QueueOwner {
+	buses := m.ProcessBuses()
+	if len(buses) == 0 {
+		return nil
+	}
+	byName := map[string]catalogue.StreamDeclaration{}
+	for _, s := range m.Streams {
+		byName[s.Name] = s
+	}
+	var out []broker.QueueOwner
+	for _, r := range m.Resources {
+		id := fmt.Sprint(r["id"])
+		b, declared := buses[id]
+		if !declared {
+			continue
+		}
+		for _, q := range b.Queues {
+			s, known := byName[q]
+			if !known || s.Retention != catalogue.StreamRetentionWorkQueue {
+				continue
+			}
+			out = append(out, broker.QueueOwner{Process: id, Stream: s.BusName(), MaxDeliver: s.MaxDeliveries})
+		}
+	}
+	return out
+}
+
 // DeclaredStreams is every module stream the catalogue declares, registered modules assigned or not: a
 // stream exists from registration, as a log does (novox/hq ADR 0363 §1).
 func (i *Inventory) DeclaredStreams(ctx context.Context) ([]broker.ModuleStream, error) {

internal/inventory/streams_test.go

@@ -65,3 +65,25 @@ func TestANonWorkQueueStreamIsCarriedAsNotAWorkQueue(t *testing.T) {
 		t.Fatalf("the plain stream: %+v", got)
 	}
 }
+
+// 1178/AC1: the process a work-queue stream's bus.queues names is read from the manifest, by its resource
+// id, with the stream's own max-deliveries — what the broker composes the one durable consumer from.
+func TestTheQueueOwnersOfAWorkQueueStreamAreReadFromItsProcess(t *testing.T) {
+	sender := catalogue.Manifest{Module: "mesh-mail", Emits: []string{"mail.send.sent", "mail.send.failed"},
+		Streams: []catalogue.StreamDeclaration{{Name: "mail-sends", Events: []string{"mail.send.approved"},
+			Retention: catalogue.StreamRetentionWorkQueue, MaxDeliveries: 5}},
+		Resources: []map[string]any{
+			{"id": "account", "type": "user", "name": "mesh-mail-send"},
+			{"id": "send", "type": "process", "run": []any{"./mesh-mail", "send"}, "user": "mesh-mail-send",
+				"bus": map[string]any{"emits": []any{"mail.send.sent", "mail.send.failed"},
+					"queues": []any{"mail-sends"}}},
+		}}
+	got := queueOwnersOf(sender)
+	if len(got) != 1 || got[0].Process != "send" || got[0].Stream != "MAIL_SENDS" || got[0].MaxDeliver != 5 {
+		t.Fatalf("the sender's queue owners: %+v", got)
+	}
+	// And a module with no process declaring bus has none.
+	if got := queueOwnersOf(catalogue.Manifest{Module: "feed"}); got != nil {
+		t.Fatalf("a module with no process bus has queue owners: %+v", got)
+	}
+}