Fixed SubscribeSync that could possibly share channel across 2 subs

Also added missing subscription's lock when setting some fields
at the end of initialization.

Fixed some flappers and missing defers.

Signed-off-by: Ivan Kozlovic <ivan@synadia.com>

js.go

@@ -1054,6 +1054,10 @@ func (js *js) subscribe(subj, queue string, cb MsgHandler, ch chan *Msg, isSync
 
 				// Use the deliver subject from latest consumer config to attach.
 				if ccfg.DeliverSubject != _EMPTY_ {
+					// We can't reuse the channel, so if one was passed, we need to create a new one.
+					if ch != nil {
+						ch = make(chan *Msg, cap(ch))
+					}
 					sub, err = js.nc.subscribe(ccfg.DeliverSubject, queue, cb, ch, isSync,
 						&jsSub{js: js, hbs: hasHeartbeats, fc: hasFC})
 					if err != nil {
@@ -1069,11 +1073,13 @@ func (js *js) subscribe(subj, queue string, cb MsgHandler, ch chan *Msg, isSync
 		consumer = info.Name
 		deliver = info.Config.DeliverSubject
 	}
+	sub.mu.Lock()
 	sub.jsi.stream = stream
 	sub.jsi.consumer = consumer
 	sub.jsi.durable = isDurable
 	sub.jsi.attached = attached
 	sub.jsi.deliver = deliver
+	sub.mu.Unlock()
 
 	return sub, nil
 }

test/js_test.go

@@ -3465,6 +3465,7 @@ func TestJetStream_UnsubscribeCloseDrain(t *testing.T) {
 	if err != nil {
 		t.Fatalf("Unexpected error: %v", err)
 	}
+	defer mc.Close()
 	jsm, err := mc.JetStream()
 	if err != nil {
 		t.Errorf("Unexpected error: %v", err)
@@ -3844,7 +3845,9 @@ func TestJetStreamSubscribe_RateLimit(t *testing.T) {
 	}
 
 	// Change rate limit.
-	recvd := make(chan *nats.Msg)
+	// Make the receive channel able to possibly hold ALL messages, but
+	// we expect it to hold less due to rate limiting.
+	recvd := make(chan *nats.Msg, totalMsgs)
 	duration := 2 * time.Second
 	ctx, cancel := context.WithTimeout(context.Background(), duration)
 	defer cancel()
@@ -3954,6 +3957,7 @@ func setupJSClusterWithSize(t *testing.T, clusterName string, size int) []*jsSer
 		t.Error(err)
 	}
 	waitForJSReady(t, nc)
+	nc.Close()
 
 	return nodes
 }
@@ -4006,6 +4010,7 @@ func withJSClusterAndStream(t *testing.T, clusterName string, size int, stream *
 		if err != nil {
 			t.Error(err)
 		}
+		defer nc.Close()
 
 		timeout := time.Now().Add(10 * time.Second)
 		for time.Now().Before(timeout) {
@@ -4084,6 +4089,7 @@ func TestJetStream_ClusterPlacement(t *testing.T) {
 			if err != nil {
 				t.Error(err)
 			}
+			defer nc.Close()
 
 			js, err := nc.JetStream()
 			if err != nil {
@@ -4112,6 +4118,7 @@ func TestJetStream_ClusterPlacement(t *testing.T) {
 			if err != nil {
 				t.Error(err)
 			}
+			defer nc.Close()
 
 			js, err := nc.JetStream()
 			if err != nil {
@@ -4141,6 +4148,7 @@ func TestJetStream_ClusterPlacement(t *testing.T) {
 			if err != nil {
 				t.Error(err)
 			}
+			defer nc.Close()
 
 			js, err := nc.JetStream()
 			if err != nil {
@@ -4176,6 +4184,7 @@ func testJetStreamMirror_Source(t *testing.T, nodes ...*jsServer) {
 	if err != nil {
 		t.Error(err)
 	}
+	defer nc.Close()
 
 	js, err := nc.JetStream()
 	if err != nil {
@@ -4631,6 +4640,7 @@ func testJetStream_ClusterMultipleSubscribe(t *testing.T, subject string, srvs .
 	if err != nil {
 		t.Fatal(err)
 	}
+	defer nc.Close()
 
 	var wg sync.WaitGroup
 	ctx, done := context.WithTimeout(context.Background(), 2*time.Second)
@@ -4711,6 +4721,7 @@ func testJetStream_ClusterMultipleQueueSubscribe(t *testing.T, subject string, s
 	if err != nil {
 		t.Fatal(err)
 	}
+	defer nc.Close()
 
 	var wg sync.WaitGroup
 	ctx, done := context.WithTimeout(context.Background(), 2*time.Second)
@@ -4792,6 +4803,7 @@ func testJetStream_ClusterMultiplePullSubscribe(t *testing.T, subject string, sr
 	if err != nil {
 		t.Fatal(err)
 	}
+	defer nc.Close()
 
 	var wg sync.WaitGroup
 	ctx, done := context.WithTimeout(context.Background(), 2*time.Second)

ws_test.go

@@ -570,6 +570,7 @@ func TestWSControlFrames(t *testing.T) {
 	nc, err := Connect(url,
 		ReconnectWait(50*time.Millisecond),
 		DisconnectErrHandler(func(_ *Conn, err error) { dch <- err }),
+		ReconnectHandler(func(_ *Conn) { rch <- true }),
 	)
 	if err != nil {
 		t.Fatalf("Error on connect: %v", err)
@@ -599,10 +600,19 @@ func TestWSControlFrames(t *testing.T) {
 	s = RunServerWithOptions(sopts)
 	defer s.Shutdown()
 
-	// Wait to reconnect
+	// Wait for both connections to reconnect
+	if err := Wait(rch); err != nil {
+		t.Fatalf("Should have reconnected: %v", err)
+	}
 	if err := Wait(rch); err != nil {
 		t.Fatalf("Should have reconnected: %v", err)
 	}
+	// Even if the first connection reconnects, there is no guarantee
+	// that the resend of SUB has yet been processed by the server.
+	// Doing a flush here will give us the guarantee.
+	if err := ncSub.Flush(); err != nil {
+		t.Fatalf("Error on flush: %v", err)
+	}
 
 	// Publish and close connection.
 	if err := nc.Publish("foo", []byte("msg")); err != nil {