swarm/network/stream: Fix flaky tests in GetSubscriptionsRPC test (#19227)

* swarm/network/stream: fixed timing issues

* swarm/network/stream: only count first iteration of subscriptions

* swarm/network/stream/: fix linter errors

swarm/network/stream/streamer_test.go

@@ -1207,7 +1207,12 @@ func TestGetSubscriptionsRPC(t *testing.T) {
 
 	// we use this subscriptionFunc for this test: just increases count and calls the actual subscription
 	subscriptionFunc = func(r *Registry, p *network.Peer, bin uint8, subs map[enode.ID]map[Stream]struct{}) bool {
+		// syncing starts after syncUpdateDelay and loops after that Duration; we only want to count at the first iteration
+		// in the first iteration, subs will be empty (no existing subscriptions), thus we can use this check
+		// this avoids flakyness
+		if len(subs) == 0 {
 			expectedMsgCount.inc()
+		}
 		doRequestSubscription(r, p, bin, subs)
 		return true
 	}
@@ -1245,19 +1250,19 @@ func TestGetSubscriptionsRPC(t *testing.T) {
 	ctx, cancelSimRun := context.WithTimeout(context.Background(), 3*time.Minute)
 	defer cancelSimRun()
 
-	// upload a snapshot
-	err := sim.UploadSnapshot(fmt.Sprintf("testing/snapshot_%d.json", nodeCount))
-	if err != nil {
-		t.Fatal(err)
-	}
-
 	// setup the filter for SubscribeMsg
 	msgs := sim.PeerEvents(
 		context.Background(),
-		sim.NodeIDs(),
+		sim.UpNodeIDs(),
 		simulation.NewPeerEventsFilter().ReceivedMessages().Protocol("stream").MsgCode(subscribeMsgCode),
 	)
 
+	// upload a snapshot
+	err := sim.UploadSnapshot(fmt.Sprintf("testing/snapshot_%d.json", nodeCount))
+	if err != nil {
+		t.Fatal(err)
+	}
+
 	// strategy: listen to all SubscribeMsg events; after every event we wait
 	// if after `waitDuration` no more messages are being received, we assume the
 	// subscription phase has terminated!
@@ -1267,9 +1272,9 @@ func TestGetSubscriptionsRPC(t *testing.T) {
 	// any new subscriptions any more
 	go func() {
 		//for long running sims, waiting 1 sec will not be enough
-		waitDuration := time.Duration(nodeCount/16) * time.Second
+		waitDuration := 1 * time.Second
 		if *longrunning {
-			waitDuration = syncUpdateDelay
+			waitDuration = 3 * time.Second
 		}
 		for {
 			select {
@@ -1335,8 +1340,10 @@ func TestGetSubscriptionsRPC(t *testing.T) {
 			log.Debug("All node streams counted", "realCount", realCount)
 		}
 		emc := expectedMsgCount.count()
-		if realCount != emc {
+		// after a subscription request, internally a live AND a history stream will be subscribed,
-			return fmt.Errorf("Real subscriptions and expected amount don't match; real: %d, expected: %d", realCount, emc)
+		// thus the real count should be half of the actual request subscriptions sent
+		if realCount/2 != emc {
+			return fmt.Errorf("Real subscriptions and expected amount don't match; real: %d, expected: %d", realCount/2, emc)
 		}
 		return nil
 	})