fix: make pubsub.unsubscribe async and alter pubsub.subscribe signature

BREAKING CHANGE: pubsub.unsubscribe is now async and argument order for pubsub.subscribe has changed

License: MIT
Signed-off-by: Alan Shaw <alan@tableflip.io>

Author: alanshaw

src/core/components/pubsub.js

@@ -4,10 +4,9 @@ const promisify = require('promisify-es6')
 
 module.exports = function pubsub (self) {
   return {
-    subscribe: (topic, options, handler, callback) => {
+    subscribe: (topic, handler, options, callback) => {
       if (typeof options === 'function') {
-        callback = handler
-        handler = options
+        callback = options
         options = {}
       }
 
@@ -20,13 +19,19 @@ module.exports = function pubsub (self) {
             resolve()
           })
         })
-      } else {
-        self._libp2pNode.pubsub.subscribe(topic, options, handler, callback)
       }
+
+      self._libp2pNode.pubsub.subscribe(topic, options, handler, callback)
     },
 
-    unsubscribe: (topic, handler) => {
+    unsubscribe: (topic, handler, callback) => {
       self._libp2pNode.pubsub.unsubscribe(topic, handler)
+
+      if (!callback) {
+        return Promise.resolve()
+      }
+
+      process.nextTick(() => callback())
     },
 
     publish: promisify((topic, data, callback) => {

src/http/api/resources/pubsub.js

@@ -33,16 +33,13 @@ exports.subscribe = {
     res.write('{}\n')
 
     const unsubscribe = () => {
-      ipfs.pubsub.unsubscribe(topic, handler)
-      res.end()
+      ipfs.pubsub.unsubscribe(topic, handler, () => res.end())
     }
 
     request.once('disconnect', unsubscribe)
     request.once('finish', unsubscribe)
 
-    ipfs.pubsub.subscribe(topic, {
-      discover: discover
-    }, handler, (err) => {
+    ipfs.pubsub.subscribe(topic, handler, { discover: discover }, (err) => {
       if (err) {
         return reply(err)
       }