fix: emit peer discovery for dht discovery

Author: vasco-santos

package.json

@@ -72,7 +72,7 @@
     "libp2p-circuit": "~0.3.0",
     "libp2p-delegated-content-routing": "~0.2.2",
     "libp2p-delegated-peer-routing": "~0.2.2",
-    "libp2p-kad-dht": "~0.14.2",
+    "libp2p-kad-dht": "~0.14.5",
     "libp2p-mdns": "~0.12.0",
     "libp2p-mplex": "~0.8.4",
     "libp2p-secio": "~0.11.0",

src/index.js

@@ -404,7 +404,10 @@ class Node extends EventEmitter {
         // have to set started here because DHT requires libp2p is already started
         this._isStarted = true
         if (this._dht) {
-          this._dht.start(cb)
+          this._dht.start(() => {
+            this._dht.on('peer', (peerInfo) => this.emit('peer:discovery', peerInfo))
+            cb()
+          })
         } else {
           cb()
         }

test/peer-discovery.node.js

@@ -7,8 +7,13 @@ const expect = chai.expect
 const sinon = require('sinon')
 const signalling = require('libp2p-webrtc-star/src/sig-server')
 const parallel = require('async/parallel')
+const retry = require('async/retry')
+const series = require('async/series')
 const crypto = require('crypto')
 
+const PeerId = require('peer-id')
+const PeerInfo = require('peer-info')
+
 const createNode = require('./utils/create-node')
 const echo = require('./utils/echo')
 
@@ -284,6 +289,68 @@ describe('peer discovery', () => {
     })
   })
 
+  describe('dht', () => {
+    setup({
+      config: {
+        peerDiscovery: {
+          mdns: {
+            enabled: false
+          },
+          webRTCStar: {
+            enabled: false
+          }
+        }
+      }
+    })
+
+    // connect two dhts
+    function connectNoSync (a, b, callback) {
+      const publicPeerId = new PeerId(b.peerInfo.id.id, null, b.peerInfo.id.pubKey)
+      const target = new PeerInfo(publicPeerId)
+      target.multiaddrs = b.peerInfo.multiaddrs
+      a.switch.dial(target, callback)
+    }
+
+    function find (a, b, cb) {
+      retry({ times: 50, interval: 100 }, (cb) => {
+        a.routingTable.find(b.peerInfo.id, (err, match) => {
+          if (err) {
+            return cb(err)
+          }
+          if (!match) {
+            return cb(new Error('not found'))
+          }
+
+          try {
+            expect(a.peerBook.get(b.peerInfo).multiaddrs.toArray()[0].toString())
+              .to.eql(b.peerInfo.multiaddrs.toArray()[0].toString())
+          } catch (err) {
+            return cb(err)
+          }
+
+          cb()
+        })
+      }, cb)
+    }
+
+    it('find a peer', function (done) {
+      this.timeout(15 * 1000)
+
+      nodeA.once('peer:discovery', (peerInfo) => {
+        expect(nodeB.peerInfo.id.toB58String())
+          .to.eql(peerInfo.id.toB58String())
+        done()
+      })
+
+      // connect to dhts
+      series([
+        (cb) => connectNoSync(nodeA._dht, nodeB._dht, cb),
+        (cb) => find(nodeA._dht, nodeB._dht, cb),
+        (cb) => find(nodeB._dht, nodeA._dht, cb)
+      ])
+    })
+  })
+
   describe('MulticastDNS + WebRTCStar', () => {
     setup({
       config: {