refactor: examples-pubsub (#504)

examples/pubsub/1.js

@@ -1,103 +1,51 @@
 /* eslint-disable no-console */
 'use strict'
 
-const libp2p = require('../../')
+const Libp2p = require('../../')
 const TCP = require('libp2p-tcp')
 const Mplex = require('libp2p-mplex')
 const SECIO = require('libp2p-secio')
 const PeerInfo = require('peer-info')
-const MulticastDNS = require('libp2p-mdns')
 const Gossipsub = require('libp2p-gossipsub')
-const defaultsDeep = require('@nodeutils/defaults-deep')
-const waterfall = require('async/waterfall')
-const parallel = require('async/parallel')
-const series = require('async/series')
 
-class MyBundle extends libp2p {
+const createNode = async () => {
-  constructor (_options) {
+  const peerInfo = await PeerInfo.create()
-    const defaults = {
+  peerInfo.multiaddrs.add('/ip4/0.0.0.0/tcp/0')
-      modules: {
+
-        transport: [ TCP ],
+  const node = await Libp2p.create({
-        streamMuxer: [ Mplex ],
+    peerInfo,
-        connEncryption: [ SECIO ],
+    modules: {
-        peerDiscovery: [ MulticastDNS ],
+      transport: [TCP],
-        pubsub: Gossipsub
+      streamMuxer: [Mplex],
-      },
+      connEncryption: [SECIO],
-      config: {
+      pubsub: Gossipsub
-        peerDiscovery: {
-          mdns: {
-            interval: 2000,
-            enabled: true
-          }
-        },
-        pubsub: {
-          enabled: true,
-          emitSelf: true
-        }
-      }
     }
-
-    super(defaultsDeep(_options, defaults))
-  }
-}
-
-function createNode (callback) {
-  let node
-
-  waterfall([
-    (cb) => PeerInfo.create(cb),
-    (peerInfo, cb) => {
-      peerInfo.multiaddrs.add('/ip4/0.0.0.0/tcp/0')
-      node = new MyBundle({
-        peerInfo
-      })
-      node.start(cb)
-    }
-  ], (err) => callback(err, node))
-}
-
-parallel([
-  (cb) => createNode(cb),
-  (cb) => createNode(cb)
-], (err, nodes) => {
-  if (err) { throw err }
-
-  const node1 = nodes[0]
-  const node2 = nodes[1]
-
-  node1.once('peer:connect', (peer) => {
-    console.log('connected to %s', peer.id.toB58String())
-
-    series([
-      // node1 subscribes to "news"
-      (cb) => node1.pubsub.subscribe(
-        'news',
-        (msg) => console.log(`node1 received: ${msg.data.toString()}`),
-        cb
-      ),
-      (cb) => setTimeout(cb, 500),
-      // node2 subscribes to "news"
-      (cb) => node2.pubsub.subscribe(
-        'news',
-        (msg) => console.log(`node2 received: ${msg.data.toString()}`),
-        cb
-      ),
-      (cb) => setTimeout(cb, 500),
-      // node2 publishes "news" every second
-      (cb) => {
-        setInterval(() => {
-          node2.pubsub.publish(
-            'news',
-            Buffer.from('Bird bird bird, bird is the word!'),
-            (err) => {
-              if (err) { throw err }
-            }
-          )
-        }, 1000)
-        cb()
-      },
-    ], (err) => {
-      if (err) { throw err }
-    })
   })
-})
+
+  await node.start()
+  return node
+}
+
+;(async () => {
+  const topic = 'news'
+
+  const [node1, node2] = await Promise.all([
+    createNode(),
+    createNode(),
+  ])
+
+  await node1.dial(node2.peerInfo)
+
+  await node1.pubsub.subscribe(topic, (msg) => {
+    console.log(`node1 received: ${msg.data.toString()}`)
+  })
+
+  await node2.pubsub.subscribe(topic, (msg) => {
+    console.log(`node2 received: ${msg.data.toString()}`)
+  })
+
+  // node2 publishes "news" every second
+  setInterval(() => {
+    node2.pubsub.publish(topic, Buffer.from('Bird bird bird, bird is the word!'))
+  }, 1000)
+})();

examples/pubsub/README.md

@@ -14,44 +14,47 @@ For this example, we will use MulticastDNS for automatic Peer Discovery. This ex
 
 Using PubSub is super simple, you only need to provide the implementation of your choice and you are ready to go. No need for extra configuration.
 
-```JavaScript
+First, let's update our libp2p configuration with a pubsub implementation.
-node1.once('peer:connect', (peer) => {
-  console.log('connected to %s', peer.id.toB58String())
 
-  series([
+```JavaScript
-    // node1 subscribes to "news"
+const Libp2p = require('libp2p')
-    (cb) => node1.pubsub.subscribe(
+const Gossipsub = require('libp2p-gossipsub')
-      'news',
+
-      (msg) => console.log(`node1 received: ${msg.data.toString()}`),
+const node = await Libp2p.create({
-      cb
+  modules: {
-    ),
+    transport: [ TCP ],
-    (cb) => setTimeout(cb, 500),
+    streamMuxer: [ Mplex ],
-    // node2 subscribes to "news"
+    connEncryption: [ SECIO ],
-    (cb) => node2.pubsub.subscribe(
+    // we add the Pubsub module we want
-      'news',
+    pubsub: Gossipsub
-      (msg) => console.log(`node2 received: ${msg.data.toString()}`),
+  }
-      cb
-    ),
-    (cb) => setTimeout(cb, 500),
-    // node2 publishes "news" every second
-    (cb) => {
-      setInterval(() => {
-        node2.pubsub.publish(
-          'news',
-          Buffer.from('Bird bird bird, bird is the word!'),
-          (err) => {
-            if (err) { throw err }
-          }
-        )
-      }, 1000)
-      cb()
-    },
-  ], (err) => {
-    if (err) { throw err }
-  })
 })
 ```
 
+Once that is done, we only need to create a few libp2p nodes, connect them and everything is ready to start using pubsub.
+
+```JavaScript
+const topic = 'news'
+
+const node1 = nodes[0]
+const node2 = nodes[1]
+
+await node1.dial(node2.peerInfo)
+
+await node1.pubsub.subscribe(topic, (msg) => {
+  console.log(`node1 received: ${msg.data.toString()}`)
+})
+
+await node2.pubsub.subscribe(topic, (msg) => {
+  console.log(`node2 received: ${msg.data.toString()}`)
+})
+
+// node2 publishes "news" every second
+setInterval(() => {
+  node2.pubsub.publish(topic, Buffer.from('Bird bird bird, bird is the word!'))
+}, 1000)
+```
+
 The output of the program should look like:
 
 ```
@@ -68,12 +71,6 @@ You can change the pubsub `emitSelf` option if you don't want the publishing nod
 ```JavaScript
 const defaults = {
   config: {
-    peerDiscovery: {
-      mdns: {
-        interval: 2000,
-        enabled: true
-      }
-    },
     pubsub: {
       enabled: true,
       emitSelf: false