fixed Topic close error

topic.go

@@ -23,6 +23,7 @@ type Topic struct {
 // Multiple event handlers may be created and will operate independently of each other
 func (t *Topic) EventHandler(opts ...TopicEventHandlerOpt) (*TopicEventHandler, error) {
 	h := &TopicEventHandler{
+		topic: t,
 		err: nil,
 
 		evtLog:   make(map[peer.ID]EventType),

topic_test.go

@@ -38,7 +38,39 @@ func getTopicEvts(topics []*Topic, opts ...TopicEventHandlerOpt) []*TopicEventHa
 	return handlers
 }
 
-func TestTopicClose(t *testing.T) {
+func TestTopicCloseWithOpenSubscription(t *testing.T) {
+	var sub *Subscription
+	var err error
+	testTopicCloseWithOpenResource(t,
+		func (topic *Topic) {
+			sub , err = topic.Subscribe()
+			if err != nil {
+				t.Fatal(err)
+			}
+		},
+		func (){
+			sub.Cancel()
+		},
+	)
+}
+
+func TestTopicCloseWithOpenEventHandler(t *testing.T) {
+	var evts *TopicEventHandler
+	var err error
+	testTopicCloseWithOpenResource(t,
+		func (topic *Topic) {
+			evts , err = topic.EventHandler()
+			if err != nil {
+				t.Fatal(err)
+			}
+		},
+		func (){
+			evts.Cancel()
+		},
+	)
+}
+
+func testTopicCloseWithOpenResource(t *testing.T, openResource func(topic *Topic), closeResource func()) {
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
 
@@ -57,23 +89,20 @@ func TestTopicClose(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	// Try create and cancel topic while there's an outstanding subscription
+	// Try create and cancel topic while there's an outstanding subscription/event handler
 	topic, err = ps.Join(topicID)
 	if err != nil {
 		t.Fatal(err)
 	}
 
-	sub, err := topic.Subscribe()
-	if err != nil {
-		t.Fatal(err)
-	}
+	openResource(topic)
 
 	if err := topic.Close(); err == nil {
-		t.Fatal("expected an error closing a topic with an open subscription")
+		t.Fatal("expected an error closing a topic with an open resource")
 	}
 
-	// Check if the topic closes properly after canceling the outstanding subscription
-	sub.Cancel()
+	// Check if the topic closes properly after closing the resource
+	closeResource()
 	time.Sleep(time.Millisecond * 100)
 
 	if err := topic.Close(); err != nil {
@@ -81,6 +110,38 @@ func TestTopicClose(t *testing.T) {
 	}
 }
 
+func TestTopicEventHandlerCancel(t *testing.T) {
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+
+	const numHosts = 5
+	topicID := "foobar"
+	hosts := getNetHosts(t, ctx, numHosts)
+	ps := getPubsub(ctx, hosts[0])
+
+	// Try create and cancel topic
+	topic, err := ps.Join(topicID)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	evts, err := topic.EventHandler()
+	if err != nil {
+		t.Fatal(err)
+	}
+	evts.Cancel()
+	timeoutCtx, timeoutCancel := context.WithTimeout(ctx, time.Second * 2)
+	defer timeoutCancel()
+	connectAll(t, hosts)
+	_, err = evts.NextPeerEvent(timeoutCtx)
+	if err != context.DeadlineExceeded {
+		if err != nil {
+			t.Fatal(err)
+		}
+		t.Fatal("received event after cancel")
+	}
+}
+
 func TestSubscriptionJoinNotification(t *testing.T) {
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()