test: Ensure pubsub topic is used when sending and retrieving messages

src/lib/waku_light_push/index.node.spec.ts

@@ -82,6 +82,7 @@ describe("Waku Light Push [node only]", () => {
     dbg("Send message via lightpush");
     const pushResponse = await waku.lightPush.push(message, {
       peerId: nimPeerId,
+      pubSubTopic: customPubSubTopic,
     });
     dbg("Ack received", pushResponse);
     expect(pushResponse?.isSuccess).to.be.true;

src/test_utils/nwaku.ts

@@ -217,7 +217,9 @@ export class Nwaku {
     ]);
   }
 
-  async messages(pubsubTopic?: string): Promise<WakuMessage[]> {
+  async messages(
+    pubsubTopic: string = DefaultPubSubTopic
+  ): Promise<WakuMessage[]> {
     this.checkProcess();
 
     const isDefined = (msg: WakuMessage | undefined): msg is WakuMessage => {
@@ -226,7 +228,7 @@ export class Nwaku {
 
     const protoMsgs = await this.rpcCall<proto.WakuMessage[]>(
       "get_waku_v2_relay_v1_messages",
-      [pubsubTopic ?? DefaultPubSubTopic]
+      [pubsubTopic]
     );
 
     const msgs = await Promise.all(