fix: pubsub do not eat error messages (#632)

* fix: allow topicCIDs from older peers

* fix: do not eat pubsub message error

* fix: lint errors

src/pubsub.js

@@ -120,6 +120,7 @@ module.exports = (arg) => {
 
   function subscribe (topic, options, handler, callback) {
     ps.on(topic, handler)
+
     if (subscriptions[topic]) {
       // TODO: should a callback error be returned?
       return callback()

src/utils/pubsub-message-stream.js

@@ -16,17 +16,18 @@ class PubsubMessageStream extends TransformStream {
   }
 
   _transform (obj, enc, callback) {
-    let msg
-    try {
-      msg = PubsubMessage.deserialize(obj, 'base64')
-    } catch (err) {
-      // Not a valid pubsub message
-      // go-ipfs returns '{}' as the very first object atm, we skip that
+    // go-ipfs returns '{}' as the very first object atm, we skip that
+    if (Object.keys(obj).length === 0) {
       return callback()
     }
 
-    this.push(msg)
-    callback()
+    try {
+      const msg = PubsubMessage.deserialize(obj, 'base64')
+      this.push(msg)
+      callback()
+    } catch (err) {
+      return callback(err)
+    }
   }
 }