fix inbox sub close panic on envoy

embassy.go

@@ -69,15 +69,16 @@ type Embassy struct {
 }
 
 type Envoy struct {
-	url       string
-	connected bool
-	terminate func()
-	queue     chan []byte
-	send      func(data []byte) error
-	events    <-chan OutboundPoolEvent
-	inbox     <-chan InboxMessage
-	eventSubs []chan<- OutboundPoolEvent
-	inboxSubs map[string][]chan<- InboxMessage
+	url               string
+	connected         bool
+	terminate         func()
+	queue             chan []byte
+	send              func(data []byte) error
+	events            <-chan OutboundPoolEvent
+	inbox             <-chan InboxMessage
+	eventSubs         []chan<- OutboundPoolEvent
+	labelledInboxSubs map[string][]chan<- InboxMessage
+	inboxSubs         []chan<- InboxMessage
 
 	ctx     context.Context
 	cancel  context.CancelFunc
@@ -312,15 +313,15 @@ func newEnvoy(
 	ctx, cancel := context.WithCancel(component.MustExtend(ctx, "envoy"))
 
 	e := &Envoy{
-		url:       url,
-		terminate: terminate,
-		queue:     make(chan []byte),
-		send:      send,
-		events:    events,
-		inbox:     inbox,
-		inboxSubs: make(map[string][]chan<- InboxMessage),
-		ctx:       ctx,
-		cancel:    cancel,
+		url:               url,
+		terminate:         terminate,
+		queue:             make(chan []byte),
+		send:              send,
+		events:            events,
+		inbox:             inbox,
+		labelledInboxSubs: make(map[string][]chan<- InboxMessage),
+		ctx:               ctx,
+		cancel:            cancel,
 	}
 
 	if handler != nil {
@@ -362,14 +363,13 @@ func (e *Envoy) Dismiss() {
 		close(sub)
 	}
 
-	for _, subs := range e.inboxSubs {
-		for _, sub := range subs {
-			close(sub)
-		}
+	for _, sub := range e.inboxSubs {
+		close(sub)
 	}
 
 	e.eventSubs = nil
-	e.inboxSubs = make(map[string][]chan<- InboxMessage)
+	e.inboxSubs = nil
+	e.labelledInboxSubs = make(map[string][]chan<- InboxMessage)
 }
 
 func (e *Envoy) Send(data []byte) error {
@@ -388,11 +388,12 @@ func (e *Envoy) SubscribeInbox(labels []string) <-chan InboxMessage {
 	e.mu.Lock()
 	defer e.mu.Unlock()
 	ch := make(chan InboxMessage)
+	e.inboxSubs = append(e.inboxSubs, ch)
 	for _, label := range labels {
-		if _, ok := e.inboxSubs[label]; !ok {
-			e.inboxSubs[label] = make([]chan<- InboxMessage, 0)
+		if _, ok := e.labelledInboxSubs[label]; !ok {
+			e.labelledInboxSubs[label] = make([]chan<- InboxMessage, 0)
 		}
-		e.inboxSubs[label] = append(e.inboxSubs[label], ch)
+		e.labelledInboxSubs[label] = append(e.labelledInboxSubs[label], ch)
 	}
 	return ch
 }
@@ -448,7 +449,7 @@ func (e *Envoy) routeInbox() {
 			}
 
 			e.mu.RLock()
-			subs, ok := e.inboxSubs[string(label)]
+			subs, ok := e.labelledInboxSubs[string(label)]
 			e.mu.RUnlock()
 
 			if !ok {

envoy_test.go

@@ -22,11 +22,21 @@ func TestEnvoy_Dismiss(t *testing.T) {
 	}
 
 	envoy := newEnvoy(ctx, url, terminate, nil, nil, nil, nil)
+
+	eventSub := envoy.SubscribeEvents()
+	inboxSub := envoy.SubscribeInbox([]string{"A", "B"})
+
 	envoy.Dismiss()
 
 	mu.RLock()
 	defer mu.RUnlock()
 	assert.True(t, terminated)
+
+	_, ok := <-eventSub
+	assert.False(t, ok)
+
+	_, ok = <-inboxSub
+	assert.False(t, ok)
 }
 
 func TestEnvoy_Send(t *testing.T) {