Do not crash when wrtc dep is missing

client.js

@@ -61,7 +61,8 @@ function Client (peerId, port, torrent, opts) {
         return new HTTPTracker(self, announceUrl, trackerOpts)
       } else if (protocol === 'udp:' && typeof UDPTracker === 'function') {
         return new UDPTracker(self, announceUrl, trackerOpts)
-      } else if (protocol === 'ws:' || protocol === 'wss:') {
+      } else if ((protocol === 'ws:' || protocol === 'wss:') &&
+          WebSocketTracker.supported) {
         return new WebSocketTracker(self, announceUrl, trackerOpts)
       }
       return null

lib/websocket-tracker.js

@@ -9,6 +9,15 @@ var inherits = require('inherits')
 var Peer = require('simple-peer')
 var Socket = require('simple-websocket')
 
+var wrtc
+try {
+  wrtc = require('wrtc') // webrtc in node - will be empty object in browser
+} catch (err) {
+  wrtc = null // optional dependency failed to install
+}
+
+var WEBRTC_SUPPORT = typeof window !== 'undefined' || !!wrtc
+
 var common = require('./common')
 
 // It turns out that you can't open multiple websockets to the same server within one
@@ -38,6 +47,8 @@ function WebSocketTracker (client, announceUrl, opts) {
   self._socket.on('data', self._onSocketData.bind(self))
 }
 
+WebSocketTracker.supported = WEBRTC_SUPPORT
+
 WebSocketTracker.prototype.announce = function (opts) {
   var self = this
   if (!self._socket.connected) {
@@ -122,7 +133,7 @@ WebSocketTracker.prototype._onSocketData = function (data) {
 
   var peer
   if (data.offer) {
-    peer = new Peer({ trickle: false, config: self._opts.rtcConfig })
+    peer = new Peer({ trickle: false, config: self._opts.rtcConfig, wrtc: wrtc })
     peer.id = common.binaryToHex(data.peer_id)
     peer.once('signal', function (answer) {
       var params = {
@@ -172,7 +183,8 @@ WebSocketTracker.prototype._generateOffers = function (numWant, cb) {
     var peer = self._peers[offerId] = new Peer({
       initiator: true,
       trickle: false,
-      config: self._opts.rtcConfig
+      config: self._opts.rtcConfig,
+      wrtc: wrtc
     })
     peer.once('signal', function (offer) {
       offers.push({

package.json

@@ -14,7 +14,8 @@
     "./lib/common-node": false,
     "./lib/http-tracker": false,
     "./lib/udp-tracker": false,
-    "./server": false
+    "./server": false,
+    "wrtc": false
   },
   "bugs": {
     "url": "https://github.com/feross/bittorrent-tracker/issues"
@@ -32,7 +33,7 @@
     "once": "^1.3.0",
     "run-series": "^1.0.2",
     "simple-get": "^1.3.0",
-    "simple-peer": "^4.0.4",
+    "simple-peer": "^5.0.0",
     "simple-websocket": "^2.0.0",
     "string2compact": "^1.1.1",
     "ws": "^0.7.1",
@@ -63,5 +64,8 @@
   },
   "scripts": {
     "test": "standard && tape test/*.js"
+  },
+  "optionalDependencies": {
+    "wrtc": "0.0.55"
   }
 }