From f5f2b93d4f79d287041ec14218310b9bdc6b565c Mon Sep 17 00:00:00 2001
From: Gareth Kirwan <gbjkirwan@gmail.com>
Date: Mon, 12 Feb 2024 15:28:55 +0700
Subject: [PATCH] Subscription: Fix Match Key no pairs candidates have pairs

---
 exchanges/kraken/kraken_test.go        | 13 ++++++++++++-
 exchanges/stream/websocket.go          |  3 +--
 exchanges/subscription/subscription.go | 11 +++++++----
 3 files changed, 20 insertions(+), 7 deletions(-)

diff --git a/exchanges/kraken/kraken_test.go b/exchanges/kraken/kraken_test.go
index 28aeb0323de..085573218e7 100644
--- a/exchanges/kraken/kraken_test.go
+++ b/exchanges/kraken/kraken_test.go
@@ -1256,6 +1256,8 @@ func TestWsSubscribe(t *testing.T) {
 func TestWsOrderbookSub(t *testing.T) {
 	t.Parallel()
 
+	k := new(Kraken)
+	require.NoError(t, testexch.TestInstance(k), "TestInstance must not error")
 	testexch.SetupWs(t, k)
 
 	err := k.Subscribe([]subscription.Subscription{{
@@ -1289,6 +1291,10 @@ func TestWsOrderbookSub(t *testing.T) {
 
 // TestWsCandlesSub tests caPairss subscription for Timeframe params
 func TestWsCandlesSub(t *testing.T) {
+	t.Parallel()
+
+	k := new(Kraken)
+	require.NoError(t, testexch.TestInstance(k), "TestInstance must not error")
 	testexch.SetupWs(t, k)
 
 	err := k.Subscribe([]subscription.Subscription{{
@@ -1322,9 +1328,14 @@ func TestWsCandlesSub(t *testing.T) {
 
 // TestWsOwnTradesSub tests the authenticated WS subscription channel for trades
 func TestWsOwnTradesSub(t *testing.T) {
-	sharedtestvalues.SkipTestIfCredentialsUnset(t, k)
+	t.Parallel()
+
+	k := new(Kraken)
+	require.NoError(t, testexch.TestInstance(k), "TestInstance must not error")
 	testexch.SetupWs(t, k)
 
+	sharedtestvalues.SkipTestIfCredentialsUnset(t, k)
+
 	err := k.Subscribe([]subscription.Subscription{{Channel: krakenWsOwnTrades}})
 	assert.NoError(t, err, "Subsrcibing to ownTrades should not error")
 
diff --git a/exchanges/stream/websocket.go b/exchanges/stream/websocket.go
index ba69b8f2c76..d115f334b97 100644
--- a/exchanges/stream/websocket.go
+++ b/exchanges/stream/websocket.go
@@ -970,8 +970,7 @@ func (w *Websocket) AddSuccessfulSubscriptions(channels ...subscription.Subscrip
 	if w.subscriptions == nil {
 		w.subscriptions = subscription.Map{}
 	}
-	for _, cN := range channels {
-		c := cN // cN is an iteration var; Not safe to make a pointer to
+	for _, c := range channels {
 		key := c.EnsureKeyed()
 		c.State = subscription.SubscribedState
 		w.subscriptions[key] = &c
diff --git a/exchanges/subscription/subscription.go b/exchanges/subscription/subscription.go
index 7cfdb670b4e..8abe3dfa03b 100644
--- a/exchanges/subscription/subscription.go
+++ b/exchanges/subscription/subscription.go
@@ -89,8 +89,8 @@ func (s *Subscription) EnsureKeyed() any {
 
 // Match returns the first subscription which matches the Key's Asset, Channel and Pairs
 // If the key provided has:
-// * Empty pairs then only Subscriptions without pairs will be considered
-// * >=1 pairs then Subscriptions which contain all the pairs will be considered
+// 1) Empty pairs then only Subscriptions without pairs will be considered
+// 2) >=1 pairs then Subscriptions which contain all the pairs will be considered
 func (k Key) Match(m Map) *Subscription {
 	for anyKey, s := range m {
 		candidate, ok := anyKey.(Key)
@@ -103,8 +103,11 @@ func (k Key) Match(m Map) *Subscription {
 		if k.Asset != candidate.Asset {
 			continue
 		}
-		if (k.Pairs == nil || len(*k.Pairs) == 0) && (candidate.Pairs == nil || len(*candidate.Pairs) == 0) {
-			return s
+		if k.Pairs == nil || len(*k.Pairs) == 0 {
+			if candidate.Pairs == nil || len(*candidate.Pairs) == 0 {
+				return s
+			}
+			continue // Case (1) - key doesn't have any pairs but candidate does
 		}
 		if err := candidate.Pairs.ContainsAll(*k.Pairs, true); err == nil {
 			return s