fix: do not unsubscribe after publish (#78)

Now that we route all messages via a `'message'` event, we can't check
the number of listeners for a given topic using the listener count.

src/index.ts

@@ -621,10 +621,6 @@ export abstract class PubSubBaseProtocol<Events = PubSubEvents> extends EventEmi
         super.dispatchEvent(new CustomEvent<Message>('message', {
           detail: rpcMessage
         }))
-
-        if (this.listenerCount(topic) === 0) {
-          this.unsubscribe(topic)
-        }
       }
     }
 
@@ -655,6 +651,8 @@ export abstract class PubSubBaseProtocol<Events = PubSubEvents> extends EventEmi
       throw new Error('Pubsub has not started')
     }
 
+    log('subscribe to topic: %s', topic)
+
     if (!this.subscriptions.has(topic)) {
       this.subscriptions.add(topic)
 
@@ -676,11 +674,10 @@ export abstract class PubSubBaseProtocol<Events = PubSubEvents> extends EventEmi
     super.removeEventListener(topic)
 
     const wasSubscribed = this.subscriptions.has(topic)
-    const listeners = this.listenerCount(topic)
 
-    log('unsubscribe from %s - am subscribed %s, listeners %d', topic, wasSubscribed, listeners)
+    log('unsubscribe from %s - am subscribed %s', topic, wasSubscribed)
 
-    if (wasSubscribed && listeners === 0) {
+    if (wasSubscribed) {
       this.subscriptions.delete(topic)
 
       for (const peerId of this.peers.keys()) {

test/pubsub.spec.ts

@@ -31,7 +31,8 @@ describe('pubsub base implementation', () => {
     beforeEach(async () => {
       const peerId = await createPeerId()
       pubsub = new PubsubImplementation({
-        multicodecs: [protocol]
+        multicodecs: [protocol],
+        emitSelf: true
       })
       pubsub.init(new Components({
         peerId: peerId,
@@ -75,6 +76,28 @@ describe('pubsub base implementation', () => {
 
       await expect(pubsub.validate(signedMessage)).to.eventually.be.undefined()
     })
+
+    it('calls publishes messages twice', async () => {
+      let count = 0
+
+      await pubsub.start()
+      pubsub.subscribe(topic)
+
+      pubsub.addEventListener('message', evt => {
+        if (evt.detail.topic === topic) {
+          count++
+        }
+      })
+      await pubsub.publish(topic, message)
+      await pubsub.publish(topic, message)
+
+      // event dispatch is async
+      await pWaitFor(() => {
+        return count === 2
+      })
+
+      expect(count).to.eql(2)
+    })
   })
 
   describe('subscribe', () => {