From c08df1603e09a719e7462d0f7cae67415366ddb4 Mon Sep 17 00:00:00 2001
From: Till Faelligen <2353100+S7evinK@users.noreply.github.com>
Date: Tue, 12 Dec 2023 11:55:01 +0100
Subject: [PATCH] Validate that the old jetstream consumers get deleted

---
 appservice/appservice_test.go | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/appservice/appservice_test.go b/appservice/appservice_test.go
index 8b5c1a32e..aa2af9f24 100644
--- a/appservice/appservice_test.go
+++ b/appservice/appservice_test.go
@@ -23,6 +23,7 @@ import (
 	uapi "github.com/matrix-org/dendrite/userapi/api"
 	"github.com/matrix-org/gomatrixserverlib"
 	"github.com/matrix-org/util"
+	"github.com/nats-io/nats.go"
 	"github.com/stretchr/testify/assert"
 	"github.com/tidwall/gjson"
 
@@ -520,12 +521,34 @@ func TestOutputAppserviceEvent(t *testing.T) {
 		// Create a dummy application service
 		cfg.AppServiceAPI.Derived.ApplicationServices = []config.ApplicationService{*as}
 
+		// Prepare AS Streams on the old topic to validate that they get deleted
+		jsCtx, _ := natsInstance.Prepare(processCtx, &cfg.Global.JetStream)
+
+		token := jetstream.Tokenise(as.ID)
+		if err := jetstream.JetStreamConsumer(
+			processCtx.Context(), jsCtx, cfg.Global.JetStream.Prefixed(jetstream.OutputRoomEvent),
+			cfg.Global.JetStream.Durable("Appservice_"+token),
+			50, // maximum number of events to send in a single transaction
+			func(ctx context.Context, msgs []*nats.Msg) bool {
+				return true
+			},
+		); err != nil {
+			t.Fatal(err)
+		}
+
 		// Start the syncAPI to have `/joined_members` available
 		syncapi.AddPublicRoutes(processCtx, routers, cfg, cm, natsInstance, usrAPI, rsAPI, caches, caching.DisableMetrics)
 
 		// start the consumer
 		appservice.NewInternalAPI(processCtx, cfg, natsInstance, usrAPI, rsAPI)
 
+		// At this point, the old JetStream consumers should be deleted
+		for consumer := range jsCtx.Consumers(cfg.Global.JetStream.Prefixed(jetstream.OutputRoomEvent)) {
+			if consumer.Name == cfg.Global.JetStream.Durable("Appservice_"+token)+"Pull" {
+				t.Fatalf("Consumer still exists")
+			}
+		}
+
 		// Create the room, this triggers the AS to receive an invite for Bob.
 		if err := rsapi.SendEvents(context.Background(), rsAPI, rsapi.KindNew, room.Events(), "test", "test", "test", nil, false); err != nil {
 			t.Fatalf("failed to send events: %v", err)