fix inbox sub close panic on envoy

embassy.go

@@ -77,7 +77,8 @@ type Envoy struct {
 	events            <-chan OutboundPoolEvent
 	inbox             <-chan InboxMessage
 	eventSubs         []chan<- OutboundPoolEvent
-	inboxSubs map[string][]chan<- InboxMessage
+	labelledInboxSubs map[string][]chan<- InboxMessage
+	inboxSubs         []chan<- InboxMessage
 
 	ctx     context.Context
 	cancel  context.CancelFunc
@@ -318,7 +319,7 @@ func newEnvoy(
 		send:              send,
 		events:            events,
 		inbox:             inbox,
-		inboxSubs: make(map[string][]chan<- InboxMessage),
+		labelledInboxSubs: make(map[string][]chan<- InboxMessage),
 		ctx:               ctx,
 		cancel:            cancel,
 	}
@@ -362,14 +363,13 @@ func (e *Envoy) Dismiss() {
 		close(sub)
 	}
 
-	for _, subs := range e.inboxSubs {
-		for _, sub := range subs {
+	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) {