From ac1a699171cfb97abf617ab0041fd4d9177260f1 Mon Sep 17 00:00:00 2001
From: Prem Chaitanya Prathi <chaitanyaprem@gmail.com>
Date: Fri, 1 Dec 2023 06:27:13 +0530
Subject: [PATCH] fix: return appropriate errors in filter unsubscribe (#941)

---
 waku/v2/protocol/filter/client.go             | 41 +++++++++++++------
 waku/v2/protocol/filter/filter_test.go        |  2 +-
 .../subscription/subscriptions_map.go         |  6 +++
 3 files changed, 36 insertions(+), 13 deletions(-)

diff --git a/waku/v2/protocol/filter/client.go b/waku/v2/protocol/filter/client.go
index 08f06b71..38449ae1 100644
--- a/waku/v2/protocol/filter/client.go
+++ b/waku/v2/protocol/filter/client.go
@@ -36,7 +36,8 @@ import (
 const FilterPushID_v20beta1 = libp2pProtocol.ID("/vac/waku/filter-push/2.0.0-beta1")
 
 var (
-	ErrNoPeersAvailable = errors.New("no suitable remote peers")
+	ErrNoPeersAvailable     = errors.New("no suitable remote peers")
+	ErrSubscriptionNotFound = errors.New("subscription not found")
 )
 
 type WakuFilterLightNode struct {
@@ -110,19 +111,21 @@ func (wf *WakuFilterLightNode) start() error {
 func (wf *WakuFilterLightNode) Stop() {
 	wf.CommonService.Stop(func() {
 		wf.h.RemoveStreamHandler(FilterPushID_v20beta1)
-		res, err := wf.unsubscribeAll(wf.Context())
-		if err != nil {
-			wf.log.Warn("unsubscribing from full nodes", zap.Error(err))
-		}
-
-		for _, r := range res.Errors() {
-			if r.Err != nil {
-				wf.log.Warn("unsubscribing from full nodes", zap.Error(r.Err), logging.HostID("peerID", r.PeerID))
+		if wf.subscriptions.Count() > 0 {
+			res, err := wf.unsubscribeAll(wf.Context())
+			if err != nil {
+				wf.log.Warn("unsubscribing from full nodes", zap.Error(err))
 			}
 
+			for _, r := range res.Errors() {
+				if r.Err != nil {
+					wf.log.Warn("unsubscribing from full nodes", zap.Error(r.Err), logging.HostID("peerID", r.PeerID))
+				}
+
+			}
+			//
+			wf.subscriptions.Clear()
 		}
-		//
-		wf.subscriptions.Clear()
 	})
 }
 
@@ -485,6 +488,13 @@ func (wf *WakuFilterLightNode) Unsubscribe(ctx context.Context, contentFilter pr
 
 		peers := make(map[peer.ID]struct{})
 		subs := wf.subscriptions.GetSubscription(params.selectedPeer, cFilter)
+		if len(subs) == 0 {
+			result.Add(WakuFilterPushError{
+				Err:    ErrSubscriptionNotFound,
+				PeerID: params.selectedPeer,
+			})
+			continue
+		}
 		for _, sub := range subs {
 			sub.Remove(cTopics...)
 			peers[sub.PeerID] = struct{}{}
@@ -583,14 +593,21 @@ func (wf *WakuFilterLightNode) unsubscribeAll(ctx context.Context, opts ...Filte
 	if err != nil {
 		return nil, err
 	}
+	result := &WakuFilterPushResult{}
 
 	peers := make(map[peer.ID]struct{})
 	subs := wf.subscriptions.GetSubscription(params.selectedPeer, protocol.ContentFilter{})
+	if len(subs) == 0 && params.selectedPeer != "" {
+		result.Add(WakuFilterPushError{
+			Err:    err,
+			PeerID: params.selectedPeer,
+		})
+		return result, ErrSubscriptionNotFound
+	}
 	for _, sub := range subs {
 		sub.Close()
 		peers[sub.PeerID] = struct{}{}
 	}
-	result := &WakuFilterPushResult{}
 	if params.wg != nil {
 		params.wg.Add(len(peers))
 	}
diff --git a/waku/v2/protocol/filter/filter_test.go b/waku/v2/protocol/filter/filter_test.go
index 5143a773..01664844 100644
--- a/waku/v2/protocol/filter/filter_test.go
+++ b/waku/v2/protocol/filter/filter_test.go
@@ -190,7 +190,7 @@ func (s *FilterTestSuite) waitForMessages(fn func(), subs []*subscription.Subscr
 						contentTopic: env.Message().GetContentTopic(),
 						payload:      string(env.Message().GetPayload()),
 					}
-					s.log.Info("received message ", zap.String("pubSubTopic", received.pubSubTopic), zap.String("contentTopic", received.contentTopic), zap.String("payload", received.payload))
+					s.log.Debug("received message ", zap.String("pubSubTopic", received.pubSubTopic), zap.String("contentTopic", received.contentTopic), zap.String("payload", received.payload))
 					if matchOneOfManyMsg(received, expected) {
 						found++
 					}
diff --git a/waku/v2/protocol/subscription/subscriptions_map.go b/waku/v2/protocol/subscription/subscriptions_map.go
index c007f623..540fe807 100644
--- a/waku/v2/protocol/subscription/subscriptions_map.go
+++ b/waku/v2/protocol/subscription/subscriptions_map.go
@@ -28,6 +28,12 @@ func NewSubscriptionMap(logger *zap.Logger) *SubscriptionsMap {
 	}
 }
 
+func (m *SubscriptionsMap) Count() int {
+        m.RLock()
+	defer m.RUnlock()
+	return len(m.items)
+}
+
 func (m *SubscriptionsMap) IsListening(pubsubTopic, contentTopic string) bool {
 	m.RLock()
 	defer m.RUnlock()