diff --git a/.eslintrc.json b/.eslintrc.json
new file mode 100644
index 0000000000..6d3c020b60
--- /dev/null
+++ b/.eslintrc.json
@@ -0,0 +1,10 @@
+{
+  "extends": "standard",
+  "parser": "babel-eslint",
+  "rules": {
+    "yoda": 0,
+    "semi": [2, "always"],
+    "no-extra-semi": 2,
+    "semi-spacing": [2, { "before": false, "after": true }]
+  }
+}
diff --git a/examples/latency/index.js b/examples/latency/index.js
index bcaae71469..2622a1a13f 100644
--- a/examples/latency/index.js
+++ b/examples/latency/index.js
@@ -3,28 +3,28 @@
  * Module dependencies.
  */
 
-var express = require('express')
-  , app = express()
-  , server = require('http').createServer(app)
-  , enchilada = require('enchilada')
-  , io = require('engine.io').attach(server);
+var express = require('express');
+var app = express();
+var server = require('http').createServer(app);
+var enchilada = require('enchilada');
+var io = require('engine.io').attach(server);
 
 app.use(enchilada({
   src: __dirname + '/public',
   debug: true
 }));
 app.use(express.static(__dirname + '/public'));
-app.get('/', function(req, res, next){
+app.get('/', function (req, res, next) {
   res.sendfile('index.html');
 });
 
-io.on('connection', function(socket){
-  socket.on('message', function(v){
+io.on('connection', function (socket) {
+  socket.on('message', function (v) {
     socket.send('pong');
   });
 });
 
 var port = process.env.PORT || 3000;
-server.listen(port, function(){
-  console.log('\033[96mlistening on localhost:' + port + ' \033[39m');
+server.listen(port, function () {
+  console.log('\x1B[96mlistening on localhost:' + port + ' \x1B[39m');
 });
diff --git a/examples/latency/public/index.js b/examples/latency/public/index.js
index 5251218940..d64f8efd2f 100644
--- a/examples/latency/public/index.js
+++ b/examples/latency/public/index.js
@@ -3,21 +3,20 @@
  * Module dependencies.
  */
 
-var SmoothieChart = require("smoothie").SmoothieChart
-  , TimeSeries = require("smoothie").TimeSeries
-  , eio = require("engine.io-client");
-
+var SmoothieChart = require('smoothie').SmoothieChart;
+var TimeSeries = require('smoothie').TimeSeries;
+var eio = require('engine.io-client');
 
 // helper
 
-function $(id){ return document.getElementById(id); }
+function $ (id) { return document.getElementById(id); }
 
 // chart
 
 var smoothie;
 var time;
 
-function render(){
+function render () {
   if (smoothie) smoothie.stop();
   $('chart').width = document.body.clientWidth;
   smoothie = new SmoothieChart();
@@ -33,25 +32,25 @@ function render(){
 // socket
 var socket = new eio.Socket();
 var last;
-function send(){
-  last = new Date;
+function send () {
+  last = new Date();
   socket.send('ping');
   $('transport').innerHTML = socket.transport.name;
 }
-socket.on('open', function(){
+socket.on('open', function () {
   if ($('chart').getContext) {
     render();
     window.onresize = render;
   }
   send();
 });
-socket.on('close', function(){
+socket.on('close', function () {
   if (smoothie) smoothie.stop();
   $('transport').innerHTML = '(disconnected)';
 });
-socket.on('message', function(){
-  var latency = new Date - last;
+socket.on('message', function () {
+  var latency = new Date() - last;
   $('latency').innerHTML = latency + 'ms';
-  if (time) time.append(+new Date, latency);
+  if (time) time.append(+new Date(), latency);
   setTimeout(send, 100);
 });
diff --git a/gulpfile.js b/gulpfile.js
index 9fb1494383..a81586b034 100644
--- a/gulpfile.js
+++ b/gulpfile.js
@@ -1,39 +1,52 @@
-var gulp = require('gulp');
-var mocha = require('gulp-mocha');
-var babel = require("gulp-babel");
-var nsp = require('gulp-nsp');
+const gulp = require('gulp');
+const mocha = require('gulp-mocha');
+const babel = require('gulp-babel');
+const nsp = require('gulp-nsp');
+const eslint = require('gulp-eslint');
 
-var TESTS = 'test/*.js';
-var REPORTER = 'dot';
+const TESTS = 'test/*.js';
+const REPORTER = 'dot';
 
-gulp.task("default", ["transpile"]);
+gulp.task('default', ['transpile']);
 
-gulp.task('test', ['nsp'], function(){
-    if (parseInt(process.versions.node) < 4 && process.env.EIO_WS_ENGINE == 'uws') {
-      console.info("Node version < 4, skipping tests with uws engine");
-      process.exit();
-    }
-    return gulp.src(TESTS, {read: false})
+gulp.task('test', ['nsp', 'lint'], function () {
+  if (parseInt(process.versions.node, 10) < 4 && process.env.EIO_WS_ENGINE === 'uws') {
+    console.info('Node version < 4, skipping tests with uws engine');
+    process.exit();
+  }
+  return gulp.src(TESTS, {read: false})
     .pipe(mocha({
       slow: 500,
       reporter: REPORTER,
       bail: true
     }))
-    .once('error', function(){
+    .once('error', function (err) {
+      console.error(err.stack);
       process.exit(1);
     })
-    .once('end', function(){
+    .once('end', function () {
       process.exit();
     });
 });
 
+gulp.task('lint', function () {
+  return gulp.src([
+    '*.js',
+    'lib/**/*.js',
+    'test/**/*.js'
+  ])
+    .pipe(eslint())
+    .pipe(eslint.format())
+    .pipe(eslint.failAfterError());
+});
+
 // By default, individual js files are transformed by babel and exported to /dist
-gulp.task("transpile", function(){
-    return gulp.src(["lib/*.js","lib/transports/*.js"], { base: 'lib' })
-        .pipe(babel({ "presets": ["es2015"] }))
-        .pipe(gulp.dest("dist"));
+gulp.task('transpile', function () {
+  return gulp.src(['lib/**/*.js'], { base: 'lib' })
+        .pipe(babel({ 'presets': ['es2015'] }))
+        .pipe(gulp.dest('dist'));
 });
 
 gulp.task('nsp', function (cb) {
-  nsp({package: __dirname + '/package.json'}, cb)
-})
+  nsp({package: __dirname + '/package.json'}, cb);
+});
diff --git a/lib/engine.io.js b/lib/engine.io.js
index dbec1de06e..c97edd615f 100644
--- a/lib/engine.io.js
+++ b/lib/engine.io.js
@@ -17,7 +17,7 @@ var http = require('http');
  * @api public
  */
 
-exports = module.exports = function() {
+exports = module.exports = function () {
   // backwards compatible use as `.attach`
   // if first argument is an http server
   if (arguments.length && arguments[0] instanceof http.Server) {
@@ -88,8 +88,8 @@ exports.parser = require('engine.io-parser');
 
 exports.listen = listen;
 
-function listen(port, options, fn) {
-  if ('function' == typeof options) {
+function listen (port, options, fn) {
+  if ('function' === typeof options) {
     fn = options;
     options = {};
   }
@@ -106,7 +106,7 @@ function listen(port, options, fn) {
   engine.httpServer = server;
 
   return engine;
-};
+}
 
 /**
  * Captures upgrade requests for a http.Server.
@@ -119,8 +119,8 @@ function listen(port, options, fn) {
 
 exports.attach = attach;
 
-function attach(server, options) {
+function attach (server, options) {
   var engine = new exports.Server(options);
   engine.attach(server, options);
   return engine;
-};
+}
diff --git a/lib/server.js b/lib/server.js
index 6af518ec64..45a1370338 100644
--- a/lib/server.js
+++ b/lib/server.js
@@ -3,15 +3,14 @@
  * Module dependencies.
  */
 
-var qs = require('querystring')
-  , parse = require('url').parse
-  , readFileSync = require('fs').readFileSync
-  , crypto = require('crypto')
-  , base64id = require('base64id')
-  , transports = require('./transports')
-  , EventEmitter = require('events').EventEmitter
-  , Socket = require('./socket')
-  , debug = require('debug')('engine');
+var qs = require('querystring');
+var parse = require('url').parse;
+var base64id = require('base64id');
+var transports = require('./transports');
+var EventEmitter = require('events').EventEmitter;
+var Socket = require('./socket');
+var util = require('util');
+var debug = require('debug')('engine');
 
 /**
  * Module exports.
@@ -26,7 +25,7 @@ module.exports = Server;
  * @api public
  */
 
-function Server(opts){
+function Server (opts) {
   if (!(this instanceof Server)) {
     return new Server(opts);
   }
@@ -60,7 +59,7 @@ function Server(opts){
   }
 
   // initialize compression options
-  ['perMessageDeflate', 'httpCompression'].forEach(function(type) {
+  ['perMessageDeflate', 'httpCompression'].forEach(function (type) {
     var compression = self[type];
     if (true === compression) self[type] = compression = {};
     if (compression && null == compression.threshold) {
@@ -103,7 +102,7 @@ Server.errorMessages = {
  * Inherits from EventEmitter.
  */
 
-Server.prototype.__proto__ = EventEmitter.prototype;
+util.inherits(Server, EventEmitter);
 
 /**
  * Hash of open clients.
@@ -120,7 +119,7 @@ Server.prototype.clients;
  * @api public
  */
 
-Server.prototype.upgrades = function(transport){
+Server.prototype.upgrades = function (transport) {
   if (!this.allowUpgrades) return [];
   return transports[transport].upgradesTo || [];
 };
@@ -133,7 +132,7 @@ Server.prototype.upgrades = function(transport){
  * @api private
  */
 
-Server.prototype.verify = function(req, upgrade, fn){
+Server.prototype.verify = function (req, upgrade, fn) {
   // transport check
   var transport = req._query.transport;
   if (!~this.transports.indexOf(transport)) {
@@ -144,15 +143,16 @@ Server.prototype.verify = function(req, upgrade, fn){
   // sid check
   var sid = req._query.sid;
   if (sid) {
-    if (!this.clients.hasOwnProperty(sid))
+    if (!this.clients.hasOwnProperty(sid)) {
       return fn(Server.errors.UNKNOWN_SID, false);
+    }
     if (!upgrade && this.clients[sid].transport.name !== transport) {
       debug('bad request: unexpected transport without upgrade');
       return fn(Server.errors.BAD_REQUEST, false);
     }
   } else {
     // handshake is GET only
-    if ('GET' != req.method) return fn(Server.errors.BAD_HANDSHAKE_METHOD, false);
+    if ('GET' !== req.method) return fn(Server.errors.BAD_HANDSHAKE_METHOD, false);
     if (!this.allowRequest) return fn(null, true);
     return this.allowRequest(req, fn);
   }
@@ -166,7 +166,7 @@ Server.prototype.verify = function(req, upgrade, fn){
  * @api private
  */
 
-Server.prototype.prepare = function(req){
+Server.prototype.prepare = function (req) {
   // try to leverage pre-existing `req._query` (e.g: from connect)
   if (!req._query) {
     req._query = ~req.url.indexOf('?') ? qs.parse(parse(req.url).query) : {};
@@ -179,7 +179,7 @@ Server.prototype.prepare = function(req){
  * @api public
  */
 
-Server.prototype.close = function(){
+Server.prototype.close = function () {
   debug('closing all open clients');
   for (var i in this.clients) {
     if (this.clients.hasOwnProperty(i)) {
@@ -202,13 +202,13 @@ Server.prototype.close = function(){
  * @api public
  */
 
-Server.prototype.handleRequest = function(req, res){
+Server.prototype.handleRequest = function (req, res) {
   debug('handling "%s" http request "%s"', req.method, req.url);
   this.prepare(req);
   req.res = res;
 
   var self = this;
-  this.verify(req, false, function(err, success) {
+  this.verify(req, false, function (err, success) {
     if (!success) {
       sendErrorMessage(req, res, err);
       return;
@@ -231,21 +231,21 @@ Server.prototype.handleRequest = function(req, res){
  * @api private
  */
 
- function sendErrorMessage(req, res, code) {
-    var headers = { 'Content-Type': 'application/json' };
+function sendErrorMessage (req, res, code) {
+  var headers = { 'Content-Type': 'application/json' };
 
-    if (req.headers.origin) {
-      headers['Access-Control-Allow-Credentials'] = 'true';
-      headers['Access-Control-Allow-Origin'] = req.headers.origin;
-    } else {
-      headers['Access-Control-Allow-Origin'] = '*';
-    }
-    res.writeHead(400, headers);
-    res.end(JSON.stringify({
-      code: code,
-      message: Server.errorMessages[code]
-    }));
- }
+  if (req.headers.origin) {
+    headers['Access-Control-Allow-Credentials'] = 'true';
+    headers['Access-Control-Allow-Origin'] = req.headers.origin;
+  } else {
+    headers['Access-Control-Allow-Origin'] = '*';
+  }
+  res.writeHead(400, headers);
+  res.end(JSON.stringify({
+    code: code,
+    message: Server.errorMessages[code]
+  }));
+}
 
 /**
  * generate a socket id.
@@ -255,7 +255,7 @@ Server.prototype.handleRequest = function(req, res){
  * @api public
  */
 
-Server.prototype.generateId = function(req){
+Server.prototype.generateId = function (req) {
   return base64id.generateId();
 };
 
@@ -267,17 +267,17 @@ Server.prototype.generateId = function(req){
  * @api private
  */
 
-Server.prototype.handshake = function(transportName, req){
+Server.prototype.handshake = function (transportName, req) {
   var id = this.generateId(req);
 
   debug('handshaking client "%s"', id);
 
   try {
     var transport = new transports[transportName](req);
-    if ('polling' == transportName) {
+    if ('polling' === transportName) {
       transport.maxHttpBufferSize = this.maxHttpBufferSize;
       transport.httpCompression = this.httpCompression;
-    } else if ('websocket' == transportName) {
+    } else if ('websocket' === transportName) {
       transport.perMessageDeflate = this.perMessageDeflate;
     }
 
@@ -286,8 +286,7 @@ Server.prototype.handshake = function(transportName, req){
     } else {
       transport.supportsBinary = true;
     }
-  }
-  catch (e) {
+  } catch (e) {
     sendErrorMessage(req, req.res, Server.errors.BAD_REQUEST);
     return;
   }
@@ -295,9 +294,9 @@ Server.prototype.handshake = function(transportName, req){
   var self = this;
 
   if (false !== this.cookie) {
-    transport.on('headers', function(headers){
+    transport.on('headers', function (headers) {
       var cookie = self.cookie + '=' + id;
-      if(false !== self.cookiePath) {
+      if (false !== self.cookiePath) {
         cookie += '; path=' + self.cookiePath;
       }
       headers['Set-Cookie'] = cookie;
@@ -309,7 +308,7 @@ Server.prototype.handshake = function(transportName, req){
   this.clients[id] = socket;
   this.clientsCount++;
 
-  socket.once('close', function(){
+  socket.once('close', function () {
     delete self.clients[id];
     self.clientsCount--;
   });
@@ -323,12 +322,12 @@ Server.prototype.handshake = function(transportName, req){
  * @api public
  */
 
-Server.prototype.handleUpgrade = function(req, socket, upgradeHead){
+Server.prototype.handleUpgrade = function (req, socket, upgradeHead) {
   this.prepare(req);
 
   var self = this;
-  this.verify(req, true, function(err, success) {
-    if (!success) {
+  this.verify(req, true, function (err, success) {
+    if (err) {
       socket.end();
       return;
     }
@@ -338,7 +337,7 @@ Server.prototype.handleUpgrade = function(req, socket, upgradeHead){
     upgradeHead = null;
 
     // delegate to ws
-    self.ws.handleUpgrade(req, socket, head, function(conn){
+    self.ws.handleUpgrade(req, socket, head, function (conn) {
       self.onWebSocket(req, conn);
     });
   });
@@ -351,7 +350,7 @@ Server.prototype.handleUpgrade = function(req, socket, upgradeHead){
  * @api private
  */
 
-Server.prototype.onWebSocket = function(req, socket){
+Server.prototype.onWebSocket = function (req, socket) {
   socket.on('error', onUpgradeError);
 
   if (!transports[req._query.transport].prototype.handlesUpgrades) {
@@ -399,7 +398,7 @@ Server.prototype.onWebSocket = function(req, socket){
     this.handshake(req._query.transport, req);
   }
 
-  function onUpgradeError(){
+  function onUpgradeError () {
     debug('websocket error before upgrade');
     // socket.close() not needed
   }
@@ -413,19 +412,18 @@ Server.prototype.onWebSocket = function(req, socket){
  * @api public
  */
 
-Server.prototype.attach = function(server, options){
+Server.prototype.attach = function (server, options) {
   var self = this;
-  var options = options || {};
+  options = options || {};
   var path = (options.path || '/engine.io').replace(/\/$/, '');
 
-  var destroyUpgrade = (options.destroyUpgrade !== undefined) ? options.destroyUpgrade : true;
   var destroyUpgradeTimeout = options.destroyUpgradeTimeout || 1000;
 
   // normalize path
   path += '/';
 
   function check (req) {
-    return path == req.url.substr(0, path.length);
+    return path === req.url.substr(0, path.length);
   }
 
   // cache and clean up listeners
@@ -434,7 +432,7 @@ Server.prototype.attach = function(server, options){
   server.on('close', self.close.bind(self));
 
   // add request handler
-  server.on('request', function(req, res){
+  server.on('request', function (req, res) {
     if (check(req)) {
       debug('intercepting request for path "%s"', path);
       self.handleRequest(req, res);
@@ -445,7 +443,7 @@ Server.prototype.attach = function(server, options){
     }
   });
 
-  if(~self.transports.indexOf('websocket')) {
+  if (~self.transports.indexOf('websocket')) {
     server.on('upgrade', function (req, socket, head) {
       if (check(req)) {
         self.handleUpgrade(req, socket, head);
@@ -454,11 +452,11 @@ Server.prototype.attach = function(server, options){
         // but by adding a handler, we prevent that
         // and if no eio thing handles the upgrade
         // then the socket needs to die!
-        setTimeout(function() {
-           if (socket.writable && socket.bytesWritten <= 0) {
-             return socket.end();
-           }
-        }, options.destroyUpgradeTimeout);
+        setTimeout(function () {
+          if (socket.writable && socket.bytesWritten <= 0) {
+            return socket.end();
+          }
+        }, destroyUpgradeTimeout);
       }
     });
   }
diff --git a/lib/socket.js b/lib/socket.js
index 57838f6159..be97d3d352 100644
--- a/lib/socket.js
+++ b/lib/socket.js
@@ -3,6 +3,7 @@
  */
 
 var EventEmitter = require('events').EventEmitter;
+var util = require('util');
 var debug = require('debug')('engine:socket');
 
 /**
@@ -44,7 +45,7 @@ function Socket (id, server, transport, req) {
  * Inherits from EventEmitter.
  */
 
-Socket.prototype.__proto__ = EventEmitter.prototype;
+util.inherits(Socket, EventEmitter);
 
 /**
  * Called upon transport considered open.
@@ -58,10 +59,10 @@ Socket.prototype.onOpen = function () {
   // sends an `open` packet
   this.transport.sid = this.id;
   this.sendPacket('open', JSON.stringify({
-      sid: this.id
-    , upgrades: this.getAvailableUpgrades()
-    , pingInterval: this.server.pingInterval
-    , pingTimeout: this.server.pingTimeout
+    sid: this.id,
+    upgrades: this.getAvailableUpgrades(),
+    pingInterval: this.server.pingInterval,
+    pingTimeout: this.server.pingTimeout
   }));
 
   this.emit('open');
@@ -76,7 +77,7 @@ Socket.prototype.onOpen = function () {
  */
 
 Socket.prototype.onPacket = function (packet) {
-  if ('open' == this.readyState) {
+  if ('open' === this.readyState) {
     // export packet event
     debug('packet');
     this.emit('packet', packet);
@@ -151,10 +152,10 @@ Socket.prototype.setTransport = function (transport) {
   this.transport.on('packet', onPacket);
   this.transport.on('drain', flush);
   this.transport.once('close', onClose);
-  //this function will manage packet events (also message callbacks)
+  // this function will manage packet events (also message callbacks)
   this.setupSendCallback();
 
-  this.cleanupFn.push(function() {
+  this.cleanupFn.push(function () {
     transport.removeListener('error', onError);
     transport.removeListener('packet', onPacket);
     transport.removeListener('drain', flush);
@@ -181,18 +182,18 @@ Socket.prototype.maybeUpgrade = function (transport) {
   self.upgradeTimeoutTimer = setTimeout(function () {
     debug('client did not complete upgrade - closing transport');
     cleanup();
-    if ('open' == transport.readyState) {
+    if ('open' === transport.readyState) {
       transport.close();
     }
   }, this.server.upgradeTimeout);
 
-  function onPacket(packet){
-    if ('ping' == packet.type && 'probe' == packet.data) {
+  function onPacket (packet) {
+    if ('ping' === packet.type && 'probe' === packet.data) {
       transport.send([{ type: 'pong', data: 'probe' }]);
       self.emit('upgrading', transport);
       clearInterval(self.checkIntervalTimer);
       self.checkIntervalTimer = setInterval(check, 100);
-    } else if ('upgrade' == packet.type && self.readyState != 'closed') {
+    } else if ('upgrade' === packet.type && self.readyState !== 'closed') {
       debug('got upgrade packet - upgrading');
       cleanup();
       self.transport.discard();
@@ -202,7 +203,7 @@ Socket.prototype.maybeUpgrade = function (transport) {
       self.emit('upgrade', transport);
       self.setPingTimeout();
       self.flush();
-      if (self.readyState == 'closing') {
+      if (self.readyState === 'closing') {
         transport.close(function () {
           self.onClose('forced close');
         });
@@ -214,14 +215,14 @@ Socket.prototype.maybeUpgrade = function (transport) {
   }
 
   // we force a polling cycle to ensure a fast upgrade
-  function check(){
-    if ('polling' == self.transport.name && self.transport.writable) {
+  function check () {
+    if ('polling' === self.transport.name && self.transport.writable) {
       debug('writing a noop packet to polling for fast upgrade');
       self.transport.send([{ type: 'noop' }]);
     }
   }
 
-  function cleanup() {
+  function cleanup () {
     self.upgrading = false;
 
     clearInterval(self.checkIntervalTimer);
@@ -236,19 +237,19 @@ Socket.prototype.maybeUpgrade = function (transport) {
     self.removeListener('close', onClose);
   }
 
-  function onError(err) {
+  function onError (err) {
     debug('client did not complete upgrade - %s', err);
     cleanup();
     transport.close();
     transport = null;
   }
 
-  function onTransportClose(){
-    onError("transport closed");
+  function onTransportClose () {
+    onError('transport closed');
   }
 
-  function onClose() {
-    onError("socket closed");
+  function onClose () {
+    onError('socket closed');
   }
 
   transport.on('packet', onPacket);
@@ -266,10 +267,16 @@ Socket.prototype.maybeUpgrade = function (transport) {
 
 Socket.prototype.clearTransport = function () {
   var cleanup;
-  while (cleanup = this.cleanupFn.shift()) cleanup();
+
+  var toCleanUp = this.cleanupFn.length;
+
+  for (var i = 0; i < toCleanUp; i++) {
+    cleanup = this.cleanupFn.shift();
+    cleanup();
+  }
 
   // silence further transport errors and prevent uncaught exceptions
-  this.transport.on('error', function(){
+  this.transport.on('error', function () {
     debug('error triggered by discarded transport');
   });
 
@@ -286,7 +293,7 @@ Socket.prototype.clearTransport = function () {
  */
 
 Socket.prototype.onClose = function (reason, description) {
-  if ('closed' != this.readyState) {
+  if ('closed' !== this.readyState) {
     this.readyState = 'closed';
     clearTimeout(this.pingTimeoutTimer);
     clearInterval(this.checkIntervalTimer);
@@ -295,7 +302,7 @@ Socket.prototype.onClose = function (reason, description) {
     var self = this;
     // clean writeBuffer in next tick, so developers can still
     // grab the writeBuffer on 'close' event
-    process.nextTick(function() {
+    process.nextTick(function () {
       self.writeBuffer = [];
     });
     this.packetsFn = [];
@@ -315,21 +322,21 @@ Socket.prototype.setupSendCallback = function () {
   var self = this;
   this.transport.on('drain', onDrain);
 
-  this.cleanupFn.push(function() {
+  this.cleanupFn.push(function () {
     self.transport.removeListener('drain', onDrain);
   });
 
-  //the message was sent successfully, execute the callback
-  function onDrain() {
+  // the message was sent successfully, execute the callback
+  function onDrain () {
     if (self.sentCallbackFn.length > 0) {
-      var seqFn = self.sentCallbackFn.splice(0,1)[0];
-      if ('function' == typeof seqFn) {
+      var seqFn = self.sentCallbackFn.splice(0, 1)[0];
+      if ('function' === typeof seqFn) {
         debug('executing send callback');
         seqFn(self.transport);
       } else if (Array.isArray(seqFn)) {
         debug('executing batch send callback');
         for (var l = seqFn.length, i = 0; i < l; i++) {
-          if ('function' == typeof seqFn[i]) {
+          if ('function' === typeof seqFn[i]) {
             seqFn[i](self.transport);
           }
         }
@@ -349,7 +356,7 @@ Socket.prototype.setupSendCallback = function () {
  */
 
 Socket.prototype.send =
-Socket.prototype.write = function(data, options, callback){
+Socket.prototype.write = function (data, options, callback) {
   this.sendPacket('message', data, options, callback);
   return this;
 };
@@ -364,7 +371,7 @@ Socket.prototype.write = function(data, options, callback){
  */
 
 Socket.prototype.sendPacket = function (type, data, options, callback) {
-  if ('function' == typeof options) {
+  if ('function' === typeof options) {
     callback = options;
     options = null;
   }
@@ -372,7 +379,7 @@ Socket.prototype.sendPacket = function (type, data, options, callback) {
   options = options || {};
   options.compress = false !== options.compress;
 
-  if ('closing' != this.readyState) {
+  if ('closing' !== this.readyState) {
     debug('sending packet "%s" (%s)', type, data);
 
     var packet = {
@@ -386,7 +393,7 @@ Socket.prototype.sendPacket = function (type, data, options, callback) {
 
     this.writeBuffer.push(packet);
 
-    //add send callback to object
+    // add send callback to object
     this.packetsFn.push(callback);
 
     this.flush();
@@ -400,8 +407,9 @@ Socket.prototype.sendPacket = function (type, data, options, callback) {
  */
 
 Socket.prototype.flush = function () {
-  if ('closed' != this.readyState && this.transport.writable
-    && this.writeBuffer.length) {
+  if ('closed' !== this.readyState &&
+                this.transport.writable &&
+                this.writeBuffer.length) {
     debug('flushing buffer to transport');
     this.emit('flush', this.writeBuffer);
     this.server.emit('flush', this, this.writeBuffer);
@@ -430,7 +438,7 @@ Socket.prototype.getAvailableUpgrades = function () {
   var allUpgrades = this.server.upgrades(this.transport.name);
   for (var i = 0, l = allUpgrades.length; i < l; ++i) {
     var upg = allUpgrades[i];
-    if (this.server.transports.indexOf(upg) != -1) {
+    if (this.server.transports.indexOf(upg) !== -1) {
       availableUpgrades.push(upg);
     }
   }
@@ -446,7 +454,7 @@ Socket.prototype.getAvailableUpgrades = function () {
  */
 
 Socket.prototype.close = function (discard) {
-  if ('open' != this.readyState) return;
+  if ('open' !== this.readyState) return;
 
   this.readyState = 'closing';
 
diff --git a/lib/transport.js b/lib/transport.js
index fdd65db708..0da2716ded 100644
--- a/lib/transport.js
+++ b/lib/transport.js
@@ -3,9 +3,10 @@
  * Module dependencies.
  */
 
-var EventEmitter = require('events').EventEmitter
-  , parser = require('engine.io-parser')
-  , debug = require('debug')('engine:transport');
+var EventEmitter = require('events').EventEmitter;
+var parser = require('engine.io-parser');
+var util = require('util');
+var debug = require('debug')('engine:transport');
 
 /**
  * Expose the constructor.
@@ -37,7 +38,7 @@ function Transport (req) {
  * Inherits from EventEmitter.
  */
 
-Transport.prototype.__proto__ = EventEmitter.prototype;
+util.inherits(Transport, EventEmitter);
 
 /**
  * Flags the transport as discarded.
@@ -68,7 +69,7 @@ Transport.prototype.onRequest = function (req) {
  */
 
 Transport.prototype.close = function (fn) {
-  if ('closed' == this.readyState || 'closing' == this.readyState) return;
+  if ('closed' === this.readyState || 'closing' === this.readyState) return;
 
   this.readyState = 'closing';
   this.doClose(fn || noop);
diff --git a/lib/transports/index.js b/lib/transports/index.js
index e15cb78387..fcff3223a8 100644
--- a/lib/transports/index.js
+++ b/lib/transports/index.js
@@ -28,7 +28,7 @@ exports.polling.upgradesTo = ['websocket'];
  */
 
 function polling (req) {
-  if ('string' == typeof req._query.j) {
+  if ('string' === typeof req._query.j) {
     return new JSONP(req);
   } else {
     return new XHR(req);
diff --git a/lib/transports/polling-jsonp.js b/lib/transports/polling-jsonp.js
index fe9fae61fb..62e66e779c 100644
--- a/lib/transports/polling-jsonp.js
+++ b/lib/transports/polling-jsonp.js
@@ -7,6 +7,7 @@ var Polling = require('./polling');
 var qs = require('querystring');
 var rDoubleSlashes = /\\\\n/g;
 var rSlashes = /(\\)?\\n/g;
+var util = require('util');
 
 /**
  * Module exports.
@@ -25,13 +26,13 @@ function JSONP (req) {
 
   this.head = '___eio[' + (req._query.j || '').replace(/[^0-9]/g, '') + '](';
   this.foot = ');';
-};
+}
 
 /**
  * Inherits from Polling.
  */
 
-JSONP.prototype.__proto__ = Polling.prototype;
+util.inherits(JSONP, Polling);
 
 /**
  * Handles incoming data.
@@ -44,10 +45,10 @@ JSONP.prototype.onData = function (data) {
   // we leverage the qs module so that we get built-in DoS protection
   // and the fast alternative to decodeURIComponent
   data = qs.parse(data).d;
-  if ('string' == typeof data) {
-    //client will send already escaped newlines as \\\\n and newlines as \\n
+  if ('string' === typeof data) {
+    // client will send already escaped newlines as \\\\n and newlines as \\n
     // \\n must be replaced with \n and \\\\n with \\n
-    data = data.replace(rSlashes, function(match, slashes) {
+    data = data.replace(rSlashes, function (match, slashes) {
       return slashes ? match : '\n';
     });
     Polling.prototype.onData.call(this, data.replace(rDoubleSlashes, '\\n'));
diff --git a/lib/transports/polling-xhr.js b/lib/transports/polling-xhr.js
index d2f2136031..d745846928 100644
--- a/lib/transports/polling-xhr.js
+++ b/lib/transports/polling-xhr.js
@@ -4,8 +4,7 @@
  */
 
 var Polling = require('./polling');
-var Transport = require('../transport');
-var debug = require('debug')('engine:polling-xhr');
+var util = require('util');
 
 /**
  * Module exports.
@@ -19,7 +18,7 @@ module.exports = XHR;
  * @api public
  */
 
-function XHR(req){
+function XHR (req) {
   Polling.call(this, req);
 }
 
@@ -27,7 +26,7 @@ function XHR(req){
  * Inherits from Polling.
  */
 
-XHR.prototype.__proto__ = Polling.prototype;
+util.inherits(XHR, Polling);
 
 /**
  * Overrides `onRequest` to handle `OPTIONS`..
@@ -37,7 +36,7 @@ XHR.prototype.__proto__ = Polling.prototype;
  */
 
 XHR.prototype.onRequest = function (req) {
-  if ('OPTIONS' == req.method) {
+  if ('OPTIONS' === req.method) {
     var res = req.res;
     var headers = this.headers(req);
     headers['Access-Control-Allow-Headers'] = 'Content-Type';
@@ -56,7 +55,7 @@ XHR.prototype.onRequest = function (req) {
  * @api private
  */
 
-XHR.prototype.headers = function(req, headers){
+XHR.prototype.headers = function (req, headers) {
   headers = headers || {};
 
   if (req.headers.origin) {
diff --git a/lib/transports/polling.js b/lib/transports/polling.js
index 36b9222e6b..17e84a54fa 100644
--- a/lib/transports/polling.js
+++ b/lib/transports/polling.js
@@ -3,11 +3,12 @@
  * Module requirements.
  */
 
-var Transport = require('../transport')
-  , parser = require('engine.io-parser')
-  , zlib = require('zlib')
-  , accepts = require('accepts')
-  , debug = require('debug')('engine:polling');
+var Transport = require('../transport');
+var parser = require('engine.io-parser');
+var zlib = require('zlib');
+var accepts = require('accepts');
+var util = require('util');
+var debug = require('debug')('engine:polling');
 
 var compressionMethods = {
   gzip: zlib.createGzip,
@@ -40,7 +41,7 @@ function Polling (req) {
  * @api public.
  */
 
-Polling.prototype.__proto__ = Transport.prototype;
+util.inherits(Polling, Transport);
 
 /**
  * Transport name
@@ -60,9 +61,9 @@ Polling.prototype.name = 'polling';
 Polling.prototype.onRequest = function (req) {
   var res = req.res;
 
-  if ('GET' == req.method) {
+  if ('GET' === req.method) {
     this.onPollRequest(req, res);
-  } else if ('POST' == req.method) {
+  } else if ('POST' === req.method) {
     this.onDataRequest(req, res);
   } else {
     res.writeHead(500);
@@ -130,7 +131,7 @@ Polling.prototype.onDataRequest = function (req, res) {
     return;
   }
 
-  var isBinary = 'application/octet-stream' == req.headers['content-type'];
+  var isBinary = 'application/octet-stream' === req.headers['content-type'];
 
   this.dataReq = req;
   this.dataRes = res;
@@ -153,7 +154,7 @@ Polling.prototype.onDataRequest = function (req, res) {
 
   function onData (data) {
     var contentLength;
-    if (typeof data == 'string') {
+    if (typeof data === 'string') {
       chunks += data;
       contentLength = Buffer.byteLength(chunks);
     } else {
@@ -198,8 +199,8 @@ Polling.prototype.onDataRequest = function (req, res) {
 Polling.prototype.onData = function (data) {
   debug('received "%s"', data);
   var self = this;
-  var callback = function(packet) {
-    if ('close' == packet.type) {
+  var callback = function (packet) {
+    if ('close' === packet.type) {
       debug('got xhr close packet');
       self.onClose();
       return false;
@@ -243,8 +244,8 @@ Polling.prototype.send = function (packets) {
   }
 
   var self = this;
-  parser.encodePayload(packets, this.supportsBinary, function(data) {
-    var compress = packets.some(function(packet) {
+  parser.encodePayload(packets, this.supportsBinary, function (data) {
+    var compress = packets.some(function (packet) {
       return packet.options && packet.options.compress;
     });
     self.write(data, { compress: compress });
@@ -262,7 +263,7 @@ Polling.prototype.send = function (packets) {
 Polling.prototype.write = function (data, options) {
   debug('writing "%s"', data);
   var self = this;
-  this.doWrite(data, options, function() {
+  this.doWrite(data, options, function () {
     self.req.cleanup();
   });
 };
@@ -277,7 +278,7 @@ Polling.prototype.doWrite = function (data, options, callback) {
   var self = this;
 
   // explicit UTF-8 is required for pages not served under utf
-  var isString = typeof data == 'string';
+  var isString = typeof data === 'string';
   var contentType = isString
     ? 'text/plain; charset=UTF-8'
     : 'application/octet-stream';
@@ -303,7 +304,7 @@ Polling.prototype.doWrite = function (data, options, callback) {
     return;
   }
 
-  this.compress(data, encoding, function(err, data) {
+  this.compress(data, encoding, function (err, data) {
     if (err) {
       self.res.writeHead(500);
       self.res.end();
@@ -315,8 +316,8 @@ Polling.prototype.doWrite = function (data, options, callback) {
     respond(data);
   });
 
-  function respond(data) {
-    headers['Content-Length'] = 'string' == typeof data ? Buffer.byteLength(data) : data.length;
+  function respond (data) {
+    headers['Content-Length'] = 'string' === typeof data ? Buffer.byteLength(data) : data.length;
     self.res.writeHead(200, self.headers(self.req, headers));
     self.res.end(data);
     callback();
@@ -337,11 +338,11 @@ Polling.prototype.compress = function (data, encoding, callback) {
 
   compressionMethods[encoding](this.httpCompression)
     .on('error', callback)
-    .on('data', function(chunk) {
+    .on('data', function (chunk) {
       buffers.push(chunk);
       nread += chunk.length;
     })
-    .on('end', function() {
+    .on('end', function () {
       callback(null, Buffer.concat(buffers, nread));
     })
     .end(data);
@@ -377,7 +378,7 @@ Polling.prototype.doClose = function (fn) {
     closeTimeoutTimer = setTimeout(onClose, this.closeTimeout);
   }
 
-  function onClose() {
+  function onClose () {
     clearTimeout(closeTimeoutTimer);
     fn();
     self.onClose();
diff --git a/lib/transports/websocket.js b/lib/transports/websocket.js
index 5a16f210c0..330fd4e384 100644
--- a/lib/transports/websocket.js
+++ b/lib/transports/websocket.js
@@ -3,9 +3,10 @@
  * Module dependencies.
  */
 
-var Transport = require('../transport')
-  , parser = require('engine.io-parser')
-  , debug = require('debug')('engine:ws')
+var Transport = require('../transport');
+var parser = require('engine.io-parser');
+var util = require('util');
+var debug = require('debug')('engine:ws');
 
 /**
  * Export the constructor.
@@ -14,7 +15,7 @@ var Transport = require('../transport')
 module.exports = WebSocket;
 
 /**
- * WebSocket transport 
+ * WebSocket transport
  *
  * @param {http.ServerRequest}
  * @api public
@@ -32,13 +33,13 @@ function WebSocket (req) {
   });
   this.writable = true;
   this.perMessageDeflate = null;
-};
+}
 
 /**
  * Inherits from Transport.
  */
 
-WebSocket.prototype.__proto__ = Transport.prototype;
+util.inherits(WebSocket, Transport);
 
 /**
  * Transport name
@@ -85,8 +86,8 @@ WebSocket.prototype.onData = function (data) {
 
 WebSocket.prototype.send = function (packets) {
   var self = this;
-  packets.forEach(function(packet) {
-    parser.encodePacket(packet, self.supportsBinary, function(data) {
+  packets.forEach(function (packet) {
+    parser.encodePacket(packet, self.supportsBinary, function (data) {
       debug('writing "%s"', data);
 
       // always creates a new object since ws modifies it
@@ -96,14 +97,14 @@ WebSocket.prototype.send = function (packets) {
       }
 
       if (self.perMessageDeflate) {
-        var len = 'string' == typeof data ? Buffer.byteLength(data) : data.length;
+        var len = 'string' === typeof data ? Buffer.byteLength(data) : data.length;
         if (len < self.perMessageDeflate.threshold) {
           opts.compress = false;
         }
       }
 
       self.writable = false;
-      self.socket.send(data, opts, function (err){
+      self.socket.send(data, opts, function (err) {
         if (err) return self.onError('write error', err.stack);
         self.writable = true;
         self.emit('drain');
diff --git a/package.json b/package.json
index 307bc4adfc..a3ed3ca662 100644
--- a/package.json
+++ b/package.json
@@ -32,11 +32,15 @@
     "ws": "1.1.1"
   },
   "devDependencies": {
+    "babel-eslint": "5.0.0",
     "babel-preset-es2015": "6.3.13",
     "engine.io-client": "1.7.2",
+    "eslint-config-standard": "4.4.0",
+    "eslint-plugin-standard": "1.3.2",
     "expect.js": "0.2.0",
     "gulp": "3.9.0",
     "gulp-babel": "6.1.1",
+    "gulp-eslint": "1.1.1",
     "gulp-mocha": "2.2.0",
     "gulp-nsp": "^2.4.1",
     "mocha": "2.3.4",
diff --git a/test/.eslintrc.json b/test/.eslintrc.json
new file mode 100644
index 0000000000..7eeefc33b6
--- /dev/null
+++ b/test/.eslintrc.json
@@ -0,0 +1,5 @@
+{
+  "env": {
+    "mocha": true
+  }
+}
diff --git a/test/common.js b/test/common.js
index 1359f67d51..f5bdc0321f 100644
--- a/test/common.js
+++ b/test/common.js
@@ -10,7 +10,7 @@ var eio = require('..');
  */
 
 exports.listen = function (opts, fn) {
-  if ('function' == typeof opts) {
+  if ('function' === typeof opts) {
     fn = opts;
     opts = {};
   }
diff --git a/test/engine.io.js b/test/engine.io.js
index c171adf34f..4850c5204e 100644
--- a/test/engine.io.js
+++ b/test/engine.io.js
@@ -15,12 +15,11 @@ var http = require('http');
  */
 
 describe('engine', function () {
-
   it('should expose protocol number', function () {
     expect(eio.protocol).to.be.a('number');
   });
 
-  it('should be the same version as client', function(){
+  it('should be the same version as client', function () {
     expect(eio.protocol).to.be.a('number');
     var version = require('../package').version;
     expect(version).to.be(require('engine.io-client/package').version);
@@ -35,7 +34,7 @@ describe('engine', function () {
 
   describe('listen', function () {
     it('should open a http server that returns 501', function (done) {
-      var server = listen(function (port) {
+      listen(function (port) {
         request.get('http://localhost:%d/'.s(port), function (res) {
           expect(res.status).to.be(501);
           done();
@@ -53,15 +52,15 @@ describe('engine', function () {
     });
 
     it('should return an engine.Server', function () {
-      var server = http.createServer()
-        , engine = eio.attach(server);
+      var server = http.createServer();
+      var engine = eio.attach(server);
 
       expect(engine).to.be.an(eio.Server);
     });
 
     it('should attach engine to an http server', function (done) {
-      var server = http.createServer()
-        , engine = eio.attach(server);
+      var server = http.createServer();
+      eio.attach(server);
 
       server.listen(function () {
         var uri = 'http://localhost:%d/engine.io/default/'.s(server.address().port);
@@ -76,22 +75,22 @@ describe('engine', function () {
     });
 
     it('should destroy upgrades not handled by engine', function (done) {
-      var server = http.createServer()
-        , engine = eio.attach(server);
+      var server = http.createServer();
+      eio.attach(server, { destroyUpgradeTimeout: 50 });
 
       server.listen(function () {
         var client = net.createConnection(server.address().port);
         client.setEncoding('ascii');
         client.write([
-            'GET / HTTP/1.1'
-          , 'Connection: Upgrade'
-          , 'Upgrade: IRC/6.9'
-          , '', ''
+          'GET / HTTP/1.1',
+          'Connection: Upgrade',
+          'Upgrade: IRC/6.9',
+          '', ''
         ].join('\r\n'));
 
         var check = setTimeout(function () {
           done(new Error('Client should have ended'));
-        }, 20);
+        }, 100);
 
         client.on('end', function () {
           clearTimeout(check);
@@ -101,21 +100,21 @@ describe('engine', function () {
     });
 
     it('should not destroy unhandled upgrades with destroyUpgrade:false', function (done) {
-      var server = http.createServer()
-        , engine = eio.attach(server, { destroyUpgrade: false, destroyUpgradeTimeout: 50 });
+      var server = http.createServer();
+      eio.attach(server, { destroyUpgrade: false, destroyUpgradeTimeout: 50 });
 
       server.listen(function () {
         var client = net.createConnection(server.address().port);
         client.on('connect', function () {
           client.setEncoding('ascii');
           client.write([
-              'GET / HTTP/1.1'
-            , 'Connection: Upgrade'
-            , 'Upgrade: IRC/6.9'
-            , '', ''
+            'GET / HTTP/1.1',
+            'Connection: Upgrade',
+            'Upgrade: IRC/6.9',
+            '', ''
           ].join('\r\n'));
 
-          var check = setTimeout(function () {
+          setTimeout(function () {
             client.removeListener('end', onEnd);
             done();
           }, 100);
@@ -130,24 +129,24 @@ describe('engine', function () {
     });
 
     it('should destroy unhandled upgrades with after a timeout', function (done) {
-      var server = http.createServer()
-        , engine = eio.attach(server, { destroyUpgradeTimeout: 200 });
+      var server = http.createServer();
+      eio.attach(server, { destroyUpgradeTimeout: 200 });
 
       server.listen(function () {
         var client = net.createConnection(server.address().port);
         client.on('connect', function () {
           client.setEncoding('ascii');
           client.write([
-              'GET / HTTP/1.1'
-            , 'Connection: Upgrade'
-            , 'Upgrade: IRC/6.9'
-            , '', ''
+            'GET / HTTP/1.1',
+            'Connection: Upgrade',
+            'Upgrade: IRC/6.9',
+            '', ''
           ].join('\r\n'));
 
           // send from client to server
           // tests that socket is still alive
           // this will not keep the socket open as the server does not handle it
-          setTimeout(function() {
+          setTimeout(function () {
             client.write('foo');
           }, 100);
 
@@ -161,13 +160,13 @@ describe('engine', function () {
     });
 
     it('should not destroy handled upgrades with after a timeout', function (done) {
-      var server = http.createServer()
-        , engine = eio.attach(server, { destroyUpgradeTimeout: 100 });
+      var server = http.createServer();
+      eio.attach(server, { destroyUpgradeTimeout: 100 });
 
       // write to the socket to keep engine.io from closing it by writing before the timeout
-      server.on('upgrade', function(req, socket) {
+      server.on('upgrade', function (req, socket) {
         socket.write('foo');
-        socket.on('data', function(chunk) {
+        socket.on('data', function (chunk) {
           expect(chunk.toString()).to.be('foo');
           socket.end();
         });
@@ -179,14 +178,14 @@ describe('engine', function () {
         client.on('connect', function () {
           client.setEncoding('ascii');
           client.write([
-              'GET / HTTP/1.1'
-            , 'Connection: Upgrade'
-            , 'Upgrade: IRC/6.9'
-            , '', ''
+            'GET / HTTP/1.1',
+            'Connection: Upgrade',
+            'Upgrade: IRC/6.9',
+            '', ''
           ].join('\r\n'));
 
           // test that socket is still open by writing after the timeout period
-          setTimeout(function() {
+          setTimeout(function () {
             client.write('foo');
           }, 200);
 
@@ -199,11 +198,11 @@ describe('engine', function () {
     });
 
     it('should preserve original request listeners', function (done) {
-      var listeners = 0
-        , server = http.createServer(function (req, res) {
-            expect(req && res).to.be.ok();
-            listeners++;
-          });
+      var listeners = 0;
+      var server = http.createServer(function (req, res) {
+        expect(req && res).to.be.ok();
+        listeners++;
+      });
 
       server.on('request', function (req, res) {
         expect(req && res).to.be.ok();
@@ -230,5 +229,4 @@ describe('engine', function () {
       });
     });
   });
-
 });
diff --git a/test/fixtures/server-close-upgraded.js b/test/fixtures/server-close-upgraded.js
index 69ff0ee2a7..dc608d30bf 100644
--- a/test/fixtures/server-close-upgraded.js
+++ b/test/fixtures/server-close-upgraded.js
@@ -3,7 +3,7 @@ var listen = require('../common').listen;
 
 var engine = listen(function (port) {
   var socket = new eioc.Socket('ws://localhost:' + port);
-  socket.on('upgrade', function() {
+  socket.on('upgrade', function () {
     engine.httpServer.close();
     engine.close();
   });
diff --git a/test/fixtures/server-close-upgrading.js b/test/fixtures/server-close-upgrading.js
index 581a1ea6e2..4ebfcc52be 100644
--- a/test/fixtures/server-close-upgrading.js
+++ b/test/fixtures/server-close-upgrading.js
@@ -3,7 +3,7 @@ var listen = require('../common').listen;
 
 var engine = listen(function (port) {
   var socket = new eioc.Socket('ws://localhost:' + port);
-  socket.on('upgrading', function() {
+  socket.on('upgrading', function () {
     engine.httpServer.close();
     engine.close();
   });
diff --git a/test/fixtures/server-close.js b/test/fixtures/server-close.js
index 259a3f45db..07c3120943 100644
--- a/test/fixtures/server-close.js
+++ b/test/fixtures/server-close.js
@@ -3,7 +3,7 @@ var listen = require('../common').listen;
 
 var engine = listen(function (port) {
   var socket = new eioc.Socket('ws://localhost:' + port);
-  socket.on('open', function() {
+  socket.on('open', function () {
     engine.httpServer.close();
     engine.close();
   });
diff --git a/test/jsonp.js b/test/jsonp.js
index 934d1ff427..b0ca0d973d 100644
--- a/test/jsonp.js
+++ b/test/jsonp.js
@@ -3,27 +3,25 @@
  * Module dependencies.
  */
 
-var http = require('http');
 var eioc = require('engine.io-client');
 var listen = require('./common').listen;
 var expect = require('expect.js');
 var request = require('superagent');
-var WebSocket = require('ws');
 
 describe('JSONP', function () {
   before(function () {
     // we have to override the browser's functionality for JSONP
-    document = {
+    document = { // eslint-disable-line no-native-reassign, no-undef
       body: {
-        appendChild: function(){},
-        removeChild: function(){}
+        appendChild: function () {},
+        removeChild: function () {}
       }
     };
 
     document.createElement = function (name) {
       var self = this;
 
-      if('script' == name) {
+      if ('script' === name) {
         var script = {};
 
         script.__defineGetter__('parentNode', function () {
@@ -31,39 +29,39 @@ describe('JSONP', function () {
         });
 
         script.__defineSetter__('src', function (uri) {
-          request.get(uri).end(function(res) {
-            eval(res.text);
+          request.get(uri).end(function (res) {
+            eval(res.text); // eslint-disable-line no-eval
           });
         });
         return script;
-      } else if ('form' == name) {
+      } else if ('form' === name) {
         var form = {
           style: {},
           action: '',
-          parentNode: { removeChild: function(){} },
-          removeChild: function(){},
-          setAttribute: function(){},
-          appendChild: function(){},
-          submit: function(){
+          parentNode: { removeChild: function () {} },
+          removeChild: function () {},
+          setAttribute: function () {},
+          appendChild: function () {},
+          submit: function () {
             request
             .post(this.action)
             .type('form')
             .send({ d: self.areaValue })
-            .end(function(){});
+            .end(function () {});
           }
         };
         return form;
-      } else if ('textarea' == name) {
+      } else if ('textarea' === name) {
         var textarea = {};
 
-        //a hack to be able to access the area data when form is sent
+        // a hack to be able to access the area data when form is sent
         textarea.__defineSetter__('value', function (data) {
           self.areaValue = data;
         });
         return textarea;
       } else if (~name.indexOf('iframe')) {
         var iframe = {};
-        setTimeout(function() {
+        setTimeout(function () {
           if (iframe.onload) iframe.onload();
         }, 0);
 
@@ -71,28 +69,28 @@ describe('JSONP', function () {
       } else {
         return {};
       }
-    }
+    };
 
     document.getElementsByTagName = function (name) {
       return [{
         parentNode: {
           insertBefore: function () {}
         }
-      }]
-    }
+      }];
+    };
   });
 
   after(function () {
-    delete document.getElementsByTagName
-      , document.createElement;
+    delete document.getElementsByTagName;
+    delete document.createElement;
     delete global.document;
   });
 
   describe('handshake', function () {
     it('should open with polling JSONP when requested', function (done) {
-      var engine = listen( { allowUpgrades: false, transports: ['polling'] }, function (port) {
-        var socket = new eioc.Socket('ws://localhost:' + port
-          , { transports: ['polling'], forceJSONP: true, upgrade: false });
+      var engine = listen({ allowUpgrades: false, transports: ['polling'] }, function (port) {
+        eioc('ws://localhost:' + port,
+          { transports: ['polling'], forceJSONP: true, upgrade: false });
         engine.on('connection', function (socket) {
           expect(socket.transport.name).to.be('polling');
           expect(socket.transport.head).to.be('___eio[0](');
@@ -105,8 +103,8 @@ describe('JSONP', function () {
   describe('messages', function () {
     var engine, port, socket;
 
-    beforeEach(function(done) {
-      engine = listen( { allowUpgrades: false, transports: ['polling'] }, function (p) {
+    beforeEach(function (done) {
+      engine = listen({ allowUpgrades: false, transports: ['polling'] }, function (p) {
         port = p;
 
         socket = new eioc.Socket('ws://localhost:' + port
@@ -134,20 +132,20 @@ describe('JSONP', function () {
     });
 
     it('should not fail JSON.parse for stringified messages', function (done) {
-      engine.on('connection', function(conn) {
-        conn.on('message', function(message) {
-          expect(JSON.parse(message)).to.be.eql({test : 'a\r\nb\n\n\n\nc'});
+      engine.on('connection', function (conn) {
+        conn.on('message', function (message) {
+          expect(JSON.parse(message)).to.be.eql({test: 'a\r\nb\n\n\n\nc'});
           done();
         });
       });
       socket.on('open', function () {
-        socket.send(JSON.stringify({test : 'a\r\nb\n\n\n\nc'}));
+        socket.send(JSON.stringify({test: 'a\r\nb\n\n\n\nc'}));
       });
     });
 
     it('should parse newlines in message correctly', function (done) {
-      engine.on('connection', function(conn) {
-        conn.on('message', function(message) {
+      engine.on('connection', function (conn) {
+        conn.on('message', function (message) {
           expect(message).to.be.equal('a\r\nb\n\n\n\nc');
           done();
         });
@@ -157,7 +155,7 @@ describe('JSONP', function () {
       });
     });
 
-    it('should arrive from server to client and back with binary data (pollingJSONP)', function(done) {
+    it('should arrive from server to client and back with binary data (pollingJSONP)', function (done) {
       var binaryData = new Buffer(5);
       for (var i = 0; i < 5; i++) binaryData[i] = i;
       engine.on('connection', function (conn) {
@@ -166,7 +164,7 @@ describe('JSONP', function () {
         });
       });
 
-      socket.on('open', function() {
+      socket.on('open', function () {
         socket.send(binaryData);
         socket.on('message', function (msg) {
           for (var i = 0; i < msg.length; i++) expect(msg[i]).to.be(i);
@@ -178,10 +176,10 @@ describe('JSONP', function () {
 
   describe('close', function () {
     it('should trigger when server closes a client', function (done) {
-      var engine = listen( { allowUpgrades: false, transports: ['polling'] }, function (port) {
-          var socket = new eioc.Socket('ws://localhost:' + port
-            , { transports: ['polling'], forceJSONP: true, upgrade: false })
-            , total = 2;
+      var engine = listen({ allowUpgrades: false, transports: ['polling'] }, function (port) {
+        var socket = new eioc.Socket('ws://localhost:' + port,
+            { transports: ['polling'], forceJSONP: true, upgrade: false });
+        var total = 2;
 
         engine.on('connection', function (conn) {
           conn.on('close', function (reason) {
@@ -203,10 +201,10 @@ describe('JSONP', function () {
     });
 
     it('should trigger when client closes', function (done) {
-      var engine = listen( { allowUpgrades: false, transports: ['polling'] }, function (port) {
+      var engine = listen({ allowUpgrades: false, transports: ['polling'] }, function (port) {
         var socket = new eioc.Socket('ws://localhost:' + port
-          , { transports: ['polling'], forceJSONP: true, upgrade: false })
-          , total = 2;
+          , { transports: ['polling'], forceJSONP: true, upgrade: false });
+        var total = 2;
 
         engine.on('connection', function (conn) {
           conn.on('close', function (reason) {
diff --git a/test/server.js b/test/server.js
index ebd5afdd0d..136025b07a 100644
--- a/test/server.js
+++ b/test/server.js
@@ -14,27 +14,25 @@ var eioc = require('engine.io-client');
 var listen = require('./common').listen;
 var expect = require('expect.js');
 var request = require('superagent');
-var WebSocket = require('ws');
 
 // are we running on node 0.8?
 var NODE_0_8 = /^v0\.8\./.test(process.version);
 // are we running on node < 4.4.3 ?
-var NODE_LT_443 = (function(){
+var NODE_LT_443 = (function () {
   var parts = process.versions.node.split('.');
   return (parts[0] < 4 || parts[1] < 4 || parts[2] < 3);
 })();
 // are we running uws wsEngine ?
-var UWS_ENGINE = process.env.EIO_WS_ENGINE == "uws";
+var UWS_ENGINE = process.env.EIO_WS_ENGINE === 'uws';
 
 /**
  * Tests.
  */
 
 describe('server', function () {
-
   describe('verification', function () {
     it('should disallow non-existent transports', function (done) {
-      var engine = listen(function (port) {
+      listen(function (port) {
         request.get('http://localhost:%d/engine.io/default/'.s(port))
           .query({ transport: 'tobi' }) // no tobi transport - outrageous
           .end(function (res) {
@@ -49,7 +47,7 @@ describe('server', function () {
 
     it('should disallow `constructor` as transports', function (done) {
       // make sure we check for actual properties - not those present on every {}
-      var engine = listen(function (port) {
+      listen(function (port) {
         request.get('http://localhost:%d/engine.io/default/'.s(port))
           .set('Origin', 'http://engine.io')
           .query({ transport: 'constructor' })
@@ -65,7 +63,7 @@ describe('server', function () {
     });
 
     it('should disallow non-existent sids', function (done) {
-      var engine = listen(function (port) {
+      listen(function (port) {
         request.get('http://localhost:%d/engine.io/default/'.s(port))
           .set('Origin', 'http://engine.io')
           .query({ transport: 'polling', sid: 'test' })
@@ -83,7 +81,7 @@ describe('server', function () {
 
   describe('handshake', function () {
     it('should send the io cookie', function (done) {
-      var engine = listen(function (port) {
+      listen(function (port) {
         request.get('http://localhost:%d/engine.io/default/'.s(port))
           .query({ transport: 'polling', b64: 1 })
           .end(function (res) {
@@ -96,7 +94,7 @@ describe('server', function () {
     });
 
     it('should send the io cookie custom name', function (done) {
-      var engine = listen({ cookie: 'woot' }, function (port) {
+      listen({ cookie: 'woot' }, function (port) {
         request.get('http://localhost:%d/engine.io/default/'.s(port))
           .query({ transport: 'polling', b64: 1 })
           .end(function (res) {
@@ -108,7 +106,7 @@ describe('server', function () {
     });
 
     it('should send the cookie with custom path', function (done) {
-      var engine = listen({ cookiePath: '/' }, function (port) {
+      listen({ cookiePath: '/' }, function (port) {
         request.get('http://localhost:%d/engine.io/default/'.s(port))
           .query({ transport: 'polling', b64: 1 })
           .end(function (res) {
@@ -120,7 +118,7 @@ describe('server', function () {
     });
 
     it('should not send the io cookie', function (done) {
-      var engine = listen({ cookie: false }, function (port) {
+      listen({ cookie: false }, function (port) {
         request.get('http://localhost:%d/engine.io/default/'.s(port))
           .query({ transport: 'polling' })
           .end(function (res) {
@@ -151,7 +149,7 @@ describe('server', function () {
 
         var customId = 'CustomId' + Date.now();
 
-        engine.generateId = function(req) {
+        engine.generateId = function (req) {
           return customId;
         };
 
@@ -167,7 +165,7 @@ describe('server', function () {
     });
 
     it('should exchange handshake data', function (done) {
-      var engine = listen({ allowUpgrades: false }, function (port) {
+      listen({ allowUpgrades: false }, function (port) {
         var socket = new eioc.Socket('ws://localhost:%d'.s(port));
         socket.on('handshake', function (obj) {
           expect(obj.sid).to.be.a('string');
@@ -179,7 +177,7 @@ describe('server', function () {
     });
 
     it('should allow custom ping timeouts', function (done) {
-      var engine = listen({ allowUpgrades: false, pingTimeout: 123 }, function (port) {
+      listen({ allowUpgrades: false, pingTimeout: 123 }, function (port) {
         var socket = new eioc.Socket('http://localhost:%d'.s(port));
         socket.on('handshake', function (obj) {
           expect(obj.pingTimeout).to.be(123);
@@ -190,7 +188,7 @@ describe('server', function () {
 
     it('should trigger a connection event with a Socket', function (done) {
       var engine = listen({ allowUpgrades: false }, function (port) {
-        var socket = new eioc.Socket('ws://localhost:%d'.s(port));
+        eioc('ws://localhost:%d'.s(port));
         engine.on('connection', function (socket) {
           expect(socket).to.be.an(eio.Socket);
           done();
@@ -200,7 +198,7 @@ describe('server', function () {
 
     it('should open with polling by default', function (done) {
       var engine = listen({ allowUpgrades: false }, function (port) {
-        var socket = new eioc.Socket('ws://localhost:%d'.s(port));
+        eioc('ws://localhost:%d'.s(port));
         engine.on('connection', function (socket) {
           expect(socket.transport.name).to.be('polling');
           done();
@@ -210,7 +208,7 @@ describe('server', function () {
 
     it('should be able to open with ws directly', function (done) {
       var engine = listen({ transports: ['websocket'] }, function (port) {
-        var socket = new eioc.Socket('ws://localhost:%d'.s(port), { transports: ['websocket'] });
+        eioc('ws://localhost:%d'.s(port), { transports: ['websocket'] });
         engine.on('connection', function (socket) {
           expect(socket.transport.name).to.be('websocket');
           done();
@@ -219,7 +217,7 @@ describe('server', function () {
     });
 
     it('should not suggest any upgrades for websocket', function (done) {
-      var engine = listen({ transports: ['websocket'] }, function (port) {
+      listen({ transports: ['websocket'] }, function (port) {
         var socket = new eioc.Socket('ws://localhost:%d'.s(port), { transports: ['websocket'] });
         socket.on('handshake', function (obj) {
           expect(obj.upgrades).to.have.length(0);
@@ -229,7 +227,7 @@ describe('server', function () {
     });
 
     it('should not suggest upgrades when none are availble', function (done) {
-      var engine = listen({ transports: ['polling'] }, function (port) {
+      listen({ transports: ['polling'] }, function (port) {
         var socket = new eioc.Socket('ws://localhost:%d'.s(port), { });
         socket.on('handshake', function (obj) {
           expect(obj.upgrades).to.have.length(0);
@@ -239,7 +237,7 @@ describe('server', function () {
     });
 
     it('should only suggest available upgrades', function (done) {
-      var engine = listen({ transports: ['polling'] }, function (port) {
+      listen({ transports: ['polling'] }, function (port) {
         var socket = new eioc.Socket('ws://localhost:%d'.s(port), { });
         socket.on('handshake', function (obj) {
           expect(obj.upgrades).to.have.length(0);
@@ -249,7 +247,7 @@ describe('server', function () {
     });
 
     it('should suggest all upgrades when no transports are disabled', function (done) {
-      var engine = listen({}, function (port) {
+      listen({}, function (port) {
         var socket = new eioc.Socket('ws://localhost:%d'.s(port), { });
         socket.on('handshake', function (obj) {
           expect(obj.upgrades).to.have.length(1);
@@ -261,10 +259,9 @@ describe('server', function () {
 
     it('default to polling when proxy doesn\'t support websocket', function (done) {
       var engine = listen({ allowUpgrades: false }, function (port) {
-
         engine.on('connection', function (socket) {
           socket.on('message', function (msg) {
-            if ('echo' == msg) socket.send(msg);
+            if ('echo' === msg) socket.send(msg);
           });
         });
 
@@ -289,7 +286,7 @@ describe('server', function () {
 
     it('should allow arbitrary data through query string', function (done) {
       var engine = listen({ allowUpgrades: false }, function (port) {
-        var socket = new eioc.Socket('ws://localhost:%d'.s(port), { query: { a: 'b' } });
+        eioc('ws://localhost:%d'.s(port), { query: { a: 'b' } });
         engine.on('connection', function (conn) {
           expect(conn.request._query).to.have.keys('transport', 'a');
           expect(conn.request._query.a).to.be('b');
@@ -300,7 +297,7 @@ describe('server', function () {
 
     it('should allow data through query string in uri', function (done) {
       var engine = listen({ allowUpgrades: false }, function (port) {
-        var socket = new eioc.Socket('ws://localhost:%d?a=b&c=d'.s(port));
+        eioc('ws://localhost:%d?a=b&c=d'.s(port));
         engine.on('connection', function (conn) {
           expect(conn.request._query.EIO).to.be.a('string');
           expect(conn.request._query.a).to.be('b');
@@ -310,10 +307,8 @@ describe('server', function () {
       });
     });
 
-
-
     it('should disallow bad requests', function (done) {
-      var engine = listen(function (port) {
+      listen(function (port) {
         request.get('http://localhost:%d/engine.io/default/'.s(port))
           .set('Origin', 'http://engine.io')
           .query({ transport: 'websocket' })
@@ -330,10 +325,10 @@ describe('server', function () {
   });
 
   describe('close', function () {
-    it('should be able to access non-empty writeBuffer at closing (server)', function(done) {
+    it('should be able to access non-empty writeBuffer at closing (server)', function (done) {
       var opts = {allowUpgrades: false};
       var engine = listen(opts, function (port) {
-        var socket = new eioc.Socket('http://localhost:%d'.s(port));
+        eioc('http://localhost:%d'.s(port));
         engine.on('connection', function (conn) {
           conn.on('close', function (reason) {
             expect(conn.writeBuffer.length).to.be(1);
@@ -342,25 +337,25 @@ describe('server', function () {
             }, 10);
             done();
           });
-          conn.writeBuffer.push({ type: 'message', data: 'foo'});
+          conn.writeBuffer.push({ type: 'message', data: 'foo' });
           conn.onError('');
         });
       });
     });
 
-    it('should be able to access non-empty writeBuffer at closing (client)', function(done) {
+    it('should be able to access non-empty writeBuffer at closing (client)', function (done) {
       var opts = {allowUpgrades: false};
-      var engine = listen(opts, function (port) {
+      listen(opts, function (port) {
         var socket = new eioc.Socket('http://localhost:%d'.s(port));
-        socket.on('open', function() {
+        socket.on('open', function () {
           socket.on('close', function (reason) {
             expect(socket.writeBuffer.length).to.be(1);
-            setTimeout(function() {
+            setTimeout(function () {
               expect(socket.writeBuffer.length).to.be(0);
             }, 10);
             done();
           });
-          socket.writeBuffer.push({ type: 'message', data: 'foo'});
+          socket.writeBuffer.push({ type: 'message', data: 'foo' });
           socket.onError('');
         });
       });
@@ -370,7 +365,7 @@ describe('server', function () {
       var opts = { allowUpgrades: false, pingInterval: 5, pingTimeout: 5 };
       var engine = listen(opts, function (port) {
         var socket = new eioc.Socket('http://localhost:%d'.s(port));
-        socket.sendPacket = function (){};
+        socket.sendPacket = function () {};
         engine.on('connection', function (conn) {
           conn.on('close', function (reason) {
             expect(reason).to.be('ping timeout');
@@ -390,7 +385,7 @@ describe('server', function () {
             done();
           });
           // client abruptly disconnects, no polling request on this tick since we've just connected
-          socket.sendPacket = socket.onPacket = function (){};
+          socket.sendPacket = socket.onPacket = function () {};
           socket.close();
           // then server app tries to close the socket, since client disappeared
           conn.close();
@@ -400,12 +395,12 @@ describe('server', function () {
 
     it('should trigger on client if server does not meet ping timeout', function (done) {
       var opts = { allowUpgrades: false, pingInterval: 50, pingTimeout: 30 };
-      var engine = listen(opts, function (port) {
+      listen(opts, function (port) {
         var socket = new eioc.Socket('ws://localhost:%d'.s(port));
         socket.on('open', function () {
           // override onPacket and Transport#onClose to simulate an inactive server after handshake
-          socket.onPacket = function(){};
-          socket.transport.onClose = function(){};
+          socket.onPacket = function () {};
+          socket.transport.onClose = function () {};
           socket.on('close', function (reason, err) {
             expect(reason).to.be('ping timeout');
             done();
@@ -417,8 +412,8 @@ describe('server', function () {
     it('should trigger on both ends upon ping timeout', function (done) {
       var opts = { allowUpgrades: false, pingTimeout: 10, pingInterval: 10 };
       var engine = listen(opts, function (port) {
-        var socket = new eioc.Socket('ws://localhost:%d'.s(port))
-          , total = 2;
+        var socket = new eioc.Socket('ws://localhost:%d'.s(port));
+        var total = 2;
 
         function onClose (reason, err) {
           expect(reason).to.be('ping timeout');
@@ -431,8 +426,8 @@ describe('server', function () {
 
         socket.on('open', function () {
           // override onPacket and Transport#onClose to simulate an inactive server after handshake
-          socket.onPacket = socket.sendPacket = function(){};
-          socket.transport.onClose = function(){};
+          socket.onPacket = socket.sendPacket = function () {};
+          socket.transport.onClose = function () {};
           socket.on('close', onClose);
         });
       });
@@ -440,8 +435,8 @@ describe('server', function () {
 
     it('should trigger when server closes a client', function (done) {
       var engine = listen({ allowUpgrades: false }, function (port) {
-        var socket = new eioc.Socket('ws://localhost:%d'.s(port))
-          , total = 2;
+        var socket = new eioc.Socket('ws://localhost:%d'.s(port));
+        var total = 2;
 
         engine.on('connection', function (conn) {
           conn.on('close', function (reason) {
@@ -465,8 +460,8 @@ describe('server', function () {
     it('should trigger when server closes a client (ws)', function (done) {
       var opts = { allowUpgrades: false, transports: ['websocket'] };
       var engine = listen(opts, function (port) {
-        var socket = new eioc.Socket('ws://localhost:%d'.s(port), { transports: ['websocket'] })
-          , total = 2;
+        var socket = new eioc.Socket('ws://localhost:%d'.s(port), { transports: ['websocket'] });
+        var total = 2;
 
         engine.on('connection', function (conn) {
           conn.on('close', function (reason) {
@@ -489,8 +484,8 @@ describe('server', function () {
 
     it('should trigger when client closes', function (done) {
       var engine = listen({ allowUpgrades: false }, function (port) {
-        var socket = new eioc.Socket('ws://localhost:%d'.s(port))
-          , total = 2;
+        var socket = new eioc.Socket('ws://localhost:%d'.s(port));
+        var total = 2;
 
         engine.on('connection', function (conn) {
           conn.on('close', function (reason) {
@@ -515,8 +510,8 @@ describe('server', function () {
     it('should trigger when client closes (ws)', function (done) {
       var opts = { allowUpgrades: false, transports: ['websocket'] };
       var engine = listen(opts, function (port) {
-        var socket = new eioc.Socket('ws://localhost:%d'.s(port), { transports: ['websocket'] })
-          , total = 2;
+        var socket = new eioc.Socket('ws://localhost:%d'.s(port), { transports: ['websocket'] });
+        var total = 2;
 
         engine.on('connection', function (conn) {
           conn.on('close', function (reason) {
@@ -543,7 +538,7 @@ describe('server', function () {
         var socket = new eioc.Socket('ws://localhost:%d'.s(port));
 
         engine.on('connection', function (conn) {
-          conn.send(null, function () {socket.close();});
+          conn.send(null, function () { socket.close(); });
           conn.send('this should not be handled');
 
           conn.on('close', function (reason) {
@@ -565,12 +560,12 @@ describe('server', function () {
     });
 
     it('should abort upgrade if socket is closed (GH-35)', function (done) {
-      var engine = listen({ allowUpgrades: true }, function (port) {
+      listen({ allowUpgrades: true }, function (port) {
         var socket = new eioc.Socket('ws://localhost:%d'.s(port));
         socket.on('open', function () {
           socket.close();
           // we wait until complete to see if we get an uncaught EPIPE
-          setTimeout(function(){
+          setTimeout(function () {
             done();
           }, 100);
         });
@@ -584,29 +579,29 @@ describe('server', function () {
         // see: https://github.com/driverdan/node-XMLHttpRequest/issues/44
         var request = require('http').request;
         var sockets = [];
-        http.request = function(opts){
+        http.request = function (opts) {
           var req = request.apply(null, arguments);
-          req.on('socket', function(socket){
+          req.on('socket', function (socket) {
             sockets.push(socket);
           });
           return req;
         };
 
-        function done(){
+        function done () {
           http.request = request;
           $done();
         }
 
-        var socket = new eioc.Socket('ws://localhost:%d'.s(port))
-          , serverSocket;
+        var socket = new eioc.Socket('ws://localhost:%d'.s(port));
+        var serverSocket;
 
-        engine.on('connection', function(s){
+        engine.on('connection', function (s) {
           serverSocket = s;
         });
 
-        socket.transport.on('poll', function(){
+        socket.transport.on('poll', function () {
           // we set a timer to wait for the request to actually reach
-          setTimeout(function(){
+          setTimeout(function () {
             // at this time server's `connection` should have been fired
             expect(serverSocket).to.be.an('object');
 
@@ -622,7 +617,7 @@ describe('server', function () {
 
             // kill the underlying connection
             sockets[1].end();
-            serverSocket.on('close', function(reason, err){
+            serverSocket.on('close', function (reason, err) {
               expect(reason).to.be('transport error');
               expect(err.message).to.be('poll connection closed prematurely');
               done();
@@ -632,34 +627,34 @@ describe('server', function () {
       });
     });
 
-    it('should not trigger with connection: close header', function($done){
-      var engine = listen({ allowUpgrades: false }, function(port){
+    it('should not trigger with connection: close header', function ($done) {
+      var engine = listen({ allowUpgrades: false }, function (port) {
         // intercept requests to add connection: close
         var request = http.request;
-        http.request = function(){
+        http.request = function () {
           var opts = arguments[0];
           opts.headers = opts.headers || {};
           opts.headers.Connection = 'close';
           return request.apply(this, arguments);
         };
 
-        function done(){
+        function done () {
           http.request = request;
           $done();
         }
 
-        engine.on('connection', function(socket){
-          socket.on('message', function(msg){
+        engine.on('connection', function (socket) {
+          socket.on('message', function (msg) {
             expect(msg).to.equal('test');
             socket.send('woot');
           });
         });
 
         var socket = new eioc.Socket('ws://localhost:%d'.s(port));
-        socket.on('open', function(){
+        socket.on('open', function () {
           socket.send('test');
         });
-        socket.on('message', function(msg){
+        socket.on('message', function (msg) {
           expect(msg).to.be('woot');
           done();
         });
@@ -671,12 +666,12 @@ describe('server', function () {
       // first timeout should trigger after `pingInterval + pingTimeout`,
       // not just `pingTimeout`.
       var opts = { allowUpgrades: false, pingInterval: 300, pingTimeout: 100 };
-      var engine = listen(opts, function (port) {
+      listen(opts, function (port) {
         var socket = new eioc.Socket('ws://localhost:%d'.s(port));
         var clientCloseReason = null;
 
-        socket.on('handshake', function() {
-          socket.onPacket = function(){};
+        socket.on('handshake', function () {
+          socket.onPacket = function () {};
         });
         socket.on('open', function () {
           socket.on('close', function (reason) {
@@ -684,7 +679,7 @@ describe('server', function () {
           });
         });
 
-        setTimeout(function() {
+        setTimeout(function () {
           expect(clientCloseReason).to.be(null);
           done();
         }, 200);
@@ -700,9 +695,9 @@ describe('server', function () {
         var socket = new eioc.Socket('ws://localhost:%d'.s(port));
         var clientCloseReason = null;
 
-        engine.on('connection', function(conn){
-          conn.on('heartbeat', function() {
-            conn.onPacket = function(){};
+        engine.on('connection', function (conn) {
+          conn.on('heartbeat', function () {
+            conn.onPacket = function () {};
           });
         });
 
@@ -712,7 +707,7 @@ describe('server', function () {
           });
         });
 
-        setTimeout(function() {
+        setTimeout(function () {
           expect(clientCloseReason).to.be(null);
           done();
         }, 100);
@@ -734,12 +729,12 @@ describe('server', function () {
           });
         });
 
-        engine.on('connection', function(conn){
-          conn.on('heartbeat', function() {
-            setTimeout(function() {
+        engine.on('connection', function (conn) {
+          conn.on('heartbeat', function () {
+            setTimeout(function () {
               conn.close();
             }, 20);
-            setTimeout(function() {
+            setTimeout(function () {
               expect(clientCloseReason).to.be('transport close');
               done();
             }, 100);
@@ -761,16 +756,16 @@ describe('server', function () {
           });
         });
 
-        engine.on('connection', function(conn){
-          conn.once('heartbeat', function() {
-            setTimeout(function() {
-              socket.onPacket = function(){};
+        engine.on('connection', function (conn) {
+          conn.once('heartbeat', function () {
+            setTimeout(function () {
+              socket.onPacket = function () {};
               expect(clientCloseReason).to.be(null);
             }, 150);
-            setTimeout(function() {
+            setTimeout(function () {
               expect(clientCloseReason).to.be(null);
             }, 350);
-            setTimeout(function() {
+            setTimeout(function () {
               expect(clientCloseReason).to.be('ping timeout');
               done();
             }, 500);
@@ -802,15 +797,15 @@ describe('server', function () {
 
     // tests https://github.com/LearnBoost/engine.io-client/issues/207
     // websocket test, transport error
-    it('should trigger transport close before open for ws', function(done){
+    it('should trigger transport close before open for ws', function (done) {
       var opts = { transports: ['websocket'] };
-      var engine = listen(opts, function (port) {
+      listen(opts, function (port) {
         var url = 'ws://%s:%d'.s('0.0.0.50', port);
         var socket = new eioc.Socket(url);
-        socket.on('open', function(){
+        socket.on('open', function () {
           done(new Error('Test invalidation'));
         });
-        socket.on('close', function(reason){
+        socket.on('close', function (reason) {
           expect(reason).to.be('transport error');
           done();
         });
@@ -819,14 +814,14 @@ describe('server', function () {
 
     // tests https://github.com/LearnBoost/engine.io-client/issues/207
     // polling test, transport error
-    it('should trigger transport close before open for xhr', function(done){
+    it('should trigger transport close before open for xhr', function (done) {
       var opts = { transports: ['polling'] };
-      var engine = listen(opts, function (port) {
+      listen(opts, function (port) {
         var socket = new eioc.Socket('http://invalidserver:%d'.s(port));
-        socket.on('open', function(){
+        socket.on('open', function () {
           done(new Error('Test invalidation'));
         });
-        socket.on('close', function(reason){
+        socket.on('close', function (reason) {
           expect(reason).to.be('transport error');
           done();
         });
@@ -835,14 +830,14 @@ describe('server', function () {
 
     // tests https://github.com/LearnBoost/engine.io-client/issues/207
     // websocket test, force close
-    it('should trigger force close before open for ws', function(done){
+    it('should trigger force close before open for ws', function (done) {
       var opts = { transports: ['websocket'] };
-      var engine = listen(opts, function (port) {
+      listen(opts, function (port) {
         var socket = new eioc.Socket('ws://localhost:%d'.s(port));
-        socket.on('open', function(){
+        socket.on('open', function () {
           done(new Error('Test invalidation'));
         });
-        socket.on('close', function(reason){
+        socket.on('close', function (reason) {
           expect(reason).to.be('forced close');
           done();
         });
@@ -852,14 +847,14 @@ describe('server', function () {
 
     // tests https://github.com/LearnBoost/engine.io-client/issues/207
     // polling test, force close
-    it('should trigger force close before open for xhr', function(done){
+    it('should trigger force close before open for xhr', function (done) {
       var opts = { transports: ['polling'] };
-      var engine = listen(opts, function (port) {
+      listen(opts, function (port) {
         var socket = new eioc.Socket('http://localhost:%d'.s(port));
-        socket.on('open', function(){
+        socket.on('open', function () {
           done(new Error('Test invalidation'));
         });
-        socket.on('close', function(reason){
+        socket.on('close', function (reason) {
           expect(reason).to.be('forced close');
           done();
         });
@@ -875,7 +870,7 @@ describe('server', function () {
         });
         var socket = new eioc.Socket('ws://localhost:%d'.s(port), { transports: ['websocket'] });
         // override to simulate an inactive client
-        socket.sendPacket = socket.onHeartbeat = function (){};
+        socket.sendPacket = socket.onHeartbeat = function () {};
       });
     });
 
@@ -887,7 +882,7 @@ describe('server', function () {
         });
         var socket = new eioc.Socket('ws://localhost:%d'.s(port), { transports: ['polling'] });
         // override to simulate an inactive client
-        socket.sendPacket = socket.onHeartbeat = function (){};
+        socket.sendPacket = socket.onHeartbeat = function () {};
       });
     });
 
@@ -913,7 +908,7 @@ describe('server', function () {
         });
         var socket = new eioc.Socket('ws://localhost:%d'.s(port), { transports: ['polling'] });
         socket.on('open', function () {
-          socket.transport.doWrite('invalid', function (){});
+          socket.transport.doWrite('invalid', function () {});
         });
       });
     });
@@ -926,7 +921,7 @@ describe('server', function () {
             conn.close();
           });
         });
-        new eioc.Socket('ws://localhost:%d'.s(port));
+        eioc('ws://localhost:%d'.s(port));
       });
     });
 
@@ -941,18 +936,18 @@ describe('server', function () {
         var socket = new eioc.Socket('ws://localhost:%d'.s(port));
         socket.on('upgrading', function (transport) {
           // override not to complete upgrading
-          transport.send = function (){};
+          transport.send = function () {};
         });
       });
     });
 
-    it('should not crash when messing with Object prototype', function(done){
-      Object.prototype.foo = 'bar';
+    it('should not crash when messing with Object prototype', function (done) {
+      Object.prototype.foo = 'bar'; // eslint-disable-line no-extend-native
       var engine = listen({ allowUpgrades: true }, function (port) {
         var socket = new eioc.Socket('ws://localhost:%d'.s(port));
         socket.on('open', function () {
           engine.close();
-          setTimeout(function(){
+          setTimeout(function () {
             done();
           }, 100);
         });
@@ -960,20 +955,20 @@ describe('server', function () {
     });
 
     describe('graceful close', function () {
-      function fixture(filename) {
+      function fixture (filename) {
         return process.execPath + ' ' +
           path.join(__dirname, 'fixtures', filename);
       }
 
-      it('should stop socket and timers', function(done){
+      it('should stop socket and timers', function (done) {
         exec(fixture('server-close.js'), done);
       });
 
-      it('should stop upgraded socket and timers', function(done){
+      it('should stop upgraded socket and timers', function (done) {
         exec(fixture('server-close-upgraded.js'), done);
       });
 
-      it('should stop upgrading socket and timers', function(done){
+      it('should stop upgrading socket and timers', function (done) {
         exec(fixture('server-close-upgrading.js'), done);
       });
     });
@@ -999,9 +994,9 @@ describe('server', function () {
 
     it('should arrive from server to client (multiple)', function (done) {
       var engine = listen({ allowUpgrades: false }, function (port) {
-        var socket = new eioc.Socket('ws://localhost:%d'.s(port))
-          , expected = ['a', 'b', 'c']
-          , i = 0;
+        var socket = new eioc.Socket('ws://localhost:%d'.s(port));
+        var expected = ['a', 'b', 'c'];
+        var i = 0;
 
         engine.on('connection', function (conn) {
           conn.send('a');
@@ -1034,12 +1029,12 @@ describe('server', function () {
       });
     });
 
-    it('should not be receiving data when getting a message longer than maxHttpBufferSize when polling', function(done) {
+    it('should not be receiving data when getting a message longer than maxHttpBufferSize when polling', function (done) {
       var opts = { allowUpgrades: false, transports: ['polling'], maxHttpBufferSize: 5 };
       var engine = listen(opts, function (port) {
         var socket = new eioc.Socket('ws://localhost:%d'.s(port));
         engine.on('connection', function (conn) {
-          conn.on('message', function(msg) {
+          conn.on('message', function (msg) {
             console.log(msg);
           });
         });
@@ -1050,12 +1045,12 @@ describe('server', function () {
       setTimeout(done, 1000);
     });
 
-    it('should receive data when getting a message shorter than maxHttpBufferSize when polling', function(done) {
+    it('should receive data when getting a message shorter than maxHttpBufferSize when polling', function (done) {
       var opts = { allowUpgrades: false, transports: ['polling'], maxHttpBufferSize: 5 };
       var engine = listen(opts, function (port) {
         var socket = new eioc.Socket('ws://localhost:%d'.s(port));
         engine.on('connection', function (conn) {
-          conn.on('message', function(msg) {
+          conn.on('message', function (msg) {
             expect(msg).to.be('a');
             done();
           });
@@ -1066,7 +1061,6 @@ describe('server', function () {
       });
     });
 
-
     it('should arrive from server to client (ws)', function (done) {
       var opts = { allowUpgrades: false, transports: ['websocket'] };
       var engine = listen(opts, function (port) {
@@ -1086,9 +1080,9 @@ describe('server', function () {
     it('should arrive from server to client (multiple, ws)', function (done) {
       var opts = { allowUpgrades: false, transports: ['websocket'] };
       var engine = listen(opts, function (port) {
-        var socket = new eioc.Socket('ws://localhost:%d'.s(port), { transports: ['websocket'] })
-          , expected = ['a', 'b', 'c']
-          , i = 0;
+        var socket = new eioc.Socket('ws://localhost:%d'.s(port), { transports: ['websocket'] });
+        var expected = ['a', 'b', 'c'];
+        var i = 0;
 
         engine.on('connection', function (conn) {
           conn.send('a');
@@ -1118,9 +1112,9 @@ describe('server', function () {
     it('should arrive from server to client (multiple, no delay, ws)', function (done) {
       var opts = { allowUpgrades: false, transports: ['websocket'] };
       var engine = listen(opts, function (port) {
-        var socket = new eioc.Socket('ws://localhost:%d'.s(port), { transports: ['websocket'] })
-          , expected = ['a', 'b', 'c']
-          , i = 0;
+        var socket = new eioc.Socket('ws://localhost:%d'.s(port), { transports: ['websocket'] });
+        var expected = ['a', 'b', 'c'];
+        var i = 0;
 
         engine.on('connection', function (conn) {
           conn.on('close', function () {
@@ -1150,7 +1144,7 @@ describe('server', function () {
       }
 
       var opts = { allowUpgrades: false, transports: ['websocket'] };
-      var engine = listen(opts, function(port) {
+      var engine = listen(opts, function (port) {
         var socket = new eioc.Socket('ws://localhost:%d'.s(port), { transports: ['websocket'] });
 
         engine.on('connection', function (conn) {
@@ -1158,7 +1152,7 @@ describe('server', function () {
         });
 
         socket.on('open', function () {
-          socket.on('message', function(msg) {
+          socket.on('message', function (msg) {
             for (var i = 0; i < binaryData.length; i++) {
               var num = msg.readInt8(i);
               expect(num).to.be(i);
@@ -1176,7 +1170,7 @@ describe('server', function () {
       }
 
       var opts = { allowUpgrades: false, transports: ['websocket'] };
-      var engine = listen(opts, function(port) {
+      var engine = listen(opts, function (port) {
         var socket = new eioc.Socket('ws://localhost:%d'.s(port), { transports: ['websocket'] });
 
         engine.on('connection', function (conn) {
@@ -1184,7 +1178,7 @@ describe('server', function () {
         });
 
         socket.on('open', function () {
-          socket.on('message', function(msg) {
+          socket.on('message', function (msg) {
             for (var i = 0, ii = 0; ii < binaryData.length; i += 4, ii++) {
               var num = msg.readInt32LE(i);
               expect(num).to.be((ii + 100) * 9823);
@@ -1202,7 +1196,7 @@ describe('server', function () {
       }
 
       var opts = { allowUpgrades: false, transports: ['websocket'] };
-      var engine = listen(opts, function(port) {
+      var engine = listen(opts, function (port) {
         var socket = new eioc.Socket('ws://localhost:%d'.s(port), { transports: ['websocket'] });
 
         engine.on('connection', function (conn) {
@@ -1210,7 +1204,7 @@ describe('server', function () {
         });
 
         socket.on('open', function () {
-          socket.on('message', function(msg) {
+          socket.on('message', function (msg) {
             for (var i = 0, ii = 0; ii < binaryData.length; i += 4, ii++) {
               var num = msg.readInt32LE(i);
               expect(num).to.be((ii + 100) * 9823);
@@ -1228,7 +1222,7 @@ describe('server', function () {
       }
 
       var opts = { allowUpgrades: false, transports: ['websocket'] };
-      var engine = listen(opts, function(port) {
+      var engine = listen(opts, function (port) {
         var socket = new eioc.Socket('ws://localhost:%d'.s(port), { transports: ['websocket'] });
 
         engine.on('connection', function (conn) {
@@ -1236,7 +1230,7 @@ describe('server', function () {
         });
 
         socket.on('open', function () {
-          socket.on('message', function(msg) {
+          socket.on('message', function (msg) {
             for (var i = 0; i < binaryData.length; i++) {
               var num = msg.readInt8(i);
               expect(num).to.be(i);
@@ -1254,15 +1248,15 @@ describe('server', function () {
       }
 
       var opts = { allowUpgrades: false, transports: ['polling'] };
-      var engine = listen(opts, function(port) {
+      var engine = listen(opts, function (port) {
         var socket = new eioc.Socket('ws://localhost:%d'.s(port), { transports: ['polling'] });
 
         engine.on('connection', function (conn) {
           conn.send(binaryData);
         });
 
-        socket.on('open', function() {
-          socket.on('message', function(msg) {
+        socket.on('open', function () {
+          socket.on('message', function (msg) {
             for (var i = 0; i < binaryData.length; i++) {
               var num = msg.readInt8(i);
               expect(num).to.be(i);
@@ -1281,7 +1275,7 @@ describe('server', function () {
       }
 
       var opts = { allowUpgrades: false, transports: ['websocket'] };
-      var engine = listen(opts, function(port) {
+      var engine = listen(opts, function (port) {
         var socket = new eioc.Socket('ws://localhost:%d'.s(port), { transports: ['websocket'] });
         socket.binaryType = 'arraybuffer';
 
@@ -1289,8 +1283,8 @@ describe('server', function () {
           conn.send(binaryData);
         });
 
-        socket.on('open', function() {
-          socket.on('message', function(msg) {
+        socket.on('open', function () {
+          socket.on('message', function (msg) {
             expect(msg instanceof ArrayBuffer).to.be(true);
             var intArray = new Int8Array(msg);
             for (var i = 0; i < binaryData.length; i++) {
@@ -1310,7 +1304,7 @@ describe('server', function () {
       }
 
       var opts = { allowUpgrades: false, transports: ['polling'] };
-      var engine = listen(opts, function(port) {
+      var engine = listen(opts, function (port) {
         var socket = new eioc.Socket('ws://localhost:%d'.s(port), { transports: ['polling'] });
         socket.binaryType = 'arraybuffer';
 
@@ -1318,8 +1312,8 @@ describe('server', function () {
           conn.send(binaryData);
         });
 
-        socket.on('open', function() {
-          socket.on('message', function(msg) {
+        socket.on('open', function () {
+          socket.on('message', function (msg) {
             expect(msg instanceof ArrayBuffer).to.be(true);
             var intArray = new Int8Array(msg);
             for (var i = 0; i < binaryData.length; i++) {
@@ -1332,28 +1326,27 @@ describe('server', function () {
       });
     });
 
-
-    it('should trigger a flush/drain event', function(done){
-      var engine = listen({ allowUpgrades: false }, function(port){
-        engine.on('connection', function(socket){
+    it('should trigger a flush/drain event', function (done) {
+      var engine = listen({ allowUpgrades: false }, function (port) {
+        engine.on('connection', function (socket) {
           var totalEvents = 4;
 
-          engine.on('flush', function(sock, buf){
+          engine.on('flush', function (sock, buf) {
             expect(sock).to.be(socket);
             expect(buf).to.be.an('array');
             --totalEvents || done();
           });
-          socket.on('flush', function(buf){
+          socket.on('flush', function (buf) {
             expect(buf).to.be.an('array');
             --totalEvents || done();
           });
 
-          engine.on('drain', function(sock){
+          engine.on('drain', function (sock) {
             expect(sock).to.be(socket);
             expect(socket.writeBuffer.length).to.be(0);
             --totalEvents || done();
           });
-          socket.on('drain', function(){
+          socket.on('drain', function () {
             expect(socket.writeBuffer.length).to.be(0);
             --totalEvents || done();
           });
@@ -1361,7 +1354,7 @@ describe('server', function () {
           socket.send('aaaa');
         });
 
-        new eioc.Socket('ws://localhost:%d'.s(port));
+        eioc('ws://localhost:%d'.s(port));
       });
     });
 
@@ -1385,7 +1378,7 @@ describe('server', function () {
         });
         var socket = new eioc.Socket('ws://localhost:%d'.s(port), { transports: ['websocket'] });
         socket.on('open', function () {
-          for (var i=0;i<messageCount;i++) {
+          for (var i = 0; i < messageCount; i++) {
 //            connection.send('message: ' + i);   // works
             connection.send(messagePayload + '|message: ' + i);   // does not work
           }
@@ -1400,7 +1393,7 @@ describe('server', function () {
       });
     });
 
-    it('should support chinese', function(done){
+    it('should support chinese', function (done) {
       var engine = listen({ allowUpgrades: false }, function (port) {
         var socket = new eioc.Socket('ws://localhost:%d'.s(port));
         var shi = '石室詩士施氏，嗜獅，誓食十獅。';
@@ -1409,23 +1402,23 @@ describe('server', function () {
           conn.send('.');
           conn.send(shi);
           conn.send(shi2);
-          conn.once('message', function(msg0){
+          conn.once('message', function (msg0) {
             expect(msg0).to.be('.');
-            conn.once('message', function(msg){
+            conn.once('message', function (msg) {
               expect(msg).to.be(shi);
-              conn.once('message', function(msg2){
+              conn.once('message', function (msg2) {
                 expect(msg2).to.be(shi2);
                 done();
               });
             });
           });
         });
-        socket.on('open', function(){
-          socket.once('message', function(msg0){
+        socket.on('open', function () {
+          socket.once('message', function (msg0) {
             expect(msg0).to.be('.');
-            socket.once('message', function(msg){
+            socket.once('message', function (msg) {
               expect(msg).to.be(shi);
-              socket.once('message', function(msg2){
+              socket.once('message', function (msg2) {
                 expect(msg2).to.be(shi2);
                 socket.send('.');
                 socket.send(shi);
@@ -1437,7 +1430,7 @@ describe('server', function () {
       });
     });
 
-    it('should send and receive data with key and cert (polling)', function(done){
+    it('should send and receive data with key and cert (polling)', function (done) {
       if (UWS_ENGINE && NODE_LT_443) return done();
       var srvOpts = {
         key: fs.readFileSync('test/fixtures/server.key'),
@@ -1451,34 +1444,34 @@ describe('server', function () {
         key: fs.readFileSync('test/fixtures/client.key'),
         cert: fs.readFileSync('test/fixtures/client.crt'),
         ca: fs.readFileSync('test/fixtures/ca.crt'),
-        transports: ['polling'],
+        transports: ['polling']
       };
 
-      var srv = https.createServer(srvOpts, function(req, res){
+      var srv = https.createServer(srvOpts, function (req, res) {
         res.writeHead(200);
         res.end('hello world\n');
       });
 
       var engine = eio({ transports: ['polling'], allowUpgrades: false });
       engine.attach(srv);
-      srv.listen(null, function() {
+      srv.listen(null, function () {
         var port = srv.address().port;
         var socket = new eioc.Socket('https://localhost:%d'.s(port), opts);
 
         engine.on('connection', function (conn) {
-          conn.on('message', function(msg) {
+          conn.on('message', function (msg) {
             expect(msg).to.be('hello');
             done();
           });
         });
 
-        socket.on('open', function() {
+        socket.on('open', function () {
           socket.send('hello');
         });
       });
     });
 
-    it('should send and receive data with ca when not requiring auth (polling)', function(done){
+    it('should send and receive data with ca when not requiring auth (polling)', function (done) {
       if (UWS_ENGINE && NODE_LT_443) return done();
       var srvOpts = {
         key: fs.readFileSync('test/fixtures/server.key'),
@@ -1492,31 +1485,31 @@ describe('server', function () {
         transports: ['polling']
       };
 
-      var srv = https.createServer(srvOpts, function(req, res){
+      var srv = https.createServer(srvOpts, function (req, res) {
         res.writeHead(200);
         res.end('hello world\n');
       });
 
       var engine = eio({ transports: ['polling'], allowUpgrades: false });
       engine.attach(srv);
-      srv.listen(null, function() {
+      srv.listen(null, function () {
         var port = srv.address().port;
         var socket = new eioc.Socket('https://localhost:%d'.s(port), opts);
 
         engine.on('connection', function (conn) {
-          conn.on('message', function(msg) {
+          conn.on('message', function (msg) {
             expect(msg).to.be('hello');
             done();
           });
         });
 
-        socket.on('open', function() {
+        socket.on('open', function () {
           socket.send('hello');
         });
       });
     });
 
-    it('should send and receive data with key and cert (ws)', function(done){
+    it('should send and receive data with key and cert (ws)', function (done) {
       var srvOpts = {
         key: fs.readFileSync('test/fixtures/server.key'),
         cert: fs.readFileSync('test/fixtures/server.crt'),
@@ -1532,31 +1525,31 @@ describe('server', function () {
         transports: ['websocket']
       };
 
-      var srv = https.createServer(srvOpts, function(req, res){
+      var srv = https.createServer(srvOpts, function (req, res) {
         res.writeHead(200);
         res.end('hello world\n');
       });
 
       var engine = eio({ transports: ['websocket'], allowUpgrades: false });
       engine.attach(srv);
-      srv.listen(null, function() {
+      srv.listen(null, function () {
         var port = srv.address().port;
         var socket = new eioc.Socket('https://localhost:%d'.s(port), opts);
 
         engine.on('connection', function (conn) {
-          conn.on('message', function(msg) {
+          conn.on('message', function (msg) {
             expect(msg).to.be('hello');
             done();
           });
         });
 
-        socket.on('open', function() {
+        socket.on('open', function () {
           socket.send('hello');
         });
       });
     });
 
-    it('should send and receive data with pfx (polling)', function(done){
+    it('should send and receive data with pfx (polling)', function (done) {
       if (UWS_ENGINE && NODE_LT_443) return done();
       var srvOpts = {
         key: fs.readFileSync('test/fixtures/server.key'),
@@ -1572,31 +1565,31 @@ describe('server', function () {
         transports: ['polling']
       };
 
-      var srv = https.createServer(srvOpts, function(req, res){
+      var srv = https.createServer(srvOpts, function (req, res) {
         res.writeHead(200);
         res.end('hello world\n');
       });
 
       var engine = eio({ transports: ['polling'], allowUpgrades: false });
       engine.attach(srv);
-      srv.listen(null, function() {
+      srv.listen(null, function () {
         var port = srv.address().port;
         var socket = new eioc.Socket('https://localhost:%d'.s(port), opts);
 
         engine.on('connection', function (conn) {
-          conn.on('message', function(msg) {
+          conn.on('message', function (msg) {
             expect(msg).to.be('hello');
             done();
           });
         });
 
-        socket.on('open', function() {
+        socket.on('open', function () {
           socket.send('hello');
         });
       });
     });
 
-    it('should send and receive data with pfx (ws)', function(done){
+    it('should send and receive data with pfx (ws)', function (done) {
       if (UWS_ENGINE && NODE_LT_443) return done();
       var srvOpts = {
         key: fs.readFileSync('test/fixtures/server.key'),
@@ -1612,44 +1605,44 @@ describe('server', function () {
         transports: ['websocket']
       };
 
-      var srv = https.createServer(srvOpts, function(req, res){
+      var srv = https.createServer(srvOpts, function (req, res) {
         res.writeHead(200);
         res.end('hello world\n');
       });
 
       var engine = eio({ transports: ['websocket'], allowUpgrades: false });
       engine.attach(srv);
-      srv.listen(null, function() {
+      srv.listen(null, function () {
         var port = srv.address().port;
         var socket = new eioc.Socket('https://localhost:%d'.s(port), opts);
 
         engine.on('connection', function (conn) {
-          conn.on('message', function(msg) {
+          conn.on('message', function (msg) {
             expect(msg).to.be('hello');
             done();
           });
         });
 
-        socket.on('open', function() {
+        socket.on('open', function () {
           socket.send('hello');
         });
       });
     });
   });
 
-  describe('send', function() {
-    describe('writeBuffer', function() {
+  describe('send', function () {
+    describe('writeBuffer', function () {
       it('should not empty until `drain` event (polling)', function (done) {
-        var engine = listen({ allowUpgrades: false }, function (port) {
+        listen({ allowUpgrades: false }, function (port) {
           var socket = new eioc.Socket('ws://localhost:%d'.s(port), { transports: ['polling'] });
           var totalEvents = 2;
-          socket.on('open', function() {
+          socket.on('open', function () {
             socket.send('a');
             socket.send('b');
             // writeBuffer should be nonempty, with 'a' still in it
             expect(socket.writeBuffer.length).to.eql(2);
           });
-          socket.transport.on('drain', function() {
+          socket.transport.on('drain', function () {
             expect(socket.writeBuffer.length).to.eql(--totalEvents);
             totalEvents || done();
           });
@@ -1657,16 +1650,16 @@ describe('server', function () {
       });
 
       it('should not empty until `drain` event (websocket)', function (done) {
-        var engine = listen({ allowUpgrades: false }, function (port) {
+        listen({ allowUpgrades: false }, function (port) {
           var socket = new eioc.Socket('ws://localhost:%d'.s(port), { transports: ['websocket'] });
           var totalEvents = 2;
-          socket.on('open', function() {
+          socket.on('open', function () {
             socket.send('a');
             socket.send('b');
             // writeBuffer should be nonempty, with 'a' still in it
             expect(socket.writeBuffer.length).to.eql(2);
           });
-          socket.transport.on('drain', function() {
+          socket.transport.on('drain', function () {
             expect(socket.writeBuffer.length).to.eql(--totalEvents);
             totalEvents || done();
           });
@@ -1674,21 +1667,21 @@ describe('server', function () {
       });
     });
 
-    describe('callback', function() {
+    describe('callback', function () {
       it('should execute in order when message sent (client) (polling)', function (done) {
         var engine = listen({ allowUpgrades: false }, function (port) {
           var socket = new eioc.Socket('ws://localhost:%d'.s(port), { transports: ['polling'] });
           var i = 0;
           var j = 0;
 
-          engine.on('connection', function(conn) {
-            conn.on('message', function(msg) {
+          engine.on('connection', function (conn) {
+            conn.on('message', function (msg) {
               conn.send(msg);
             });
           });
 
           socket.on('open', function () {
-            socket.on('message', function(msg) {
+            socket.on('message', function (msg) {
               // send another packet until we've sent 3 total
               if (++i < 3) {
                 expect(i).to.eql(j);
@@ -1698,8 +1691,8 @@ describe('server', function () {
               }
             });
 
-            function sendFn() {
-              socket.send(j, (function(value) {
+            function sendFn () {
+              socket.send(j, (function (value) {
                 j++;
               })(j));
             }
@@ -1715,14 +1708,14 @@ describe('server', function () {
           var i = 0;
           var j = 0;
 
-          engine.on('connection', function(conn) {
-            conn.on('message', function(msg) {
+          engine.on('connection', function (conn) {
+            conn.on('message', function (msg) {
               conn.send(msg);
             });
           });
 
           socket.on('open', function () {
-            socket.on('message', function(msg) {
+            socket.on('message', function (msg) {
               // send another packet until we've sent 3 total
               if (++i < 3) {
                 expect(i).to.eql(j);
@@ -1732,8 +1725,8 @@ describe('server', function () {
               }
             });
 
-            function sendFn() {
-              socket.send(j, (function(value) {
+            function sendFn () {
+              socket.send(j, (function (value) {
                 j++;
               })(j));
             }
@@ -1749,33 +1742,33 @@ describe('server', function () {
           var i = 0;
           var lastCbFired = 0;
 
-          engine.on('connection', function(conn) {
-            conn.on('message', function(msg) {
+          engine.on('connection', function (conn) {
+            conn.on('message', function (msg) {
               conn.send(msg);
             });
           });
 
           socket.on('open', function () {
-            socket.on('message', function(msg) {
+            socket.on('message', function (msg) {
               expect(msg).to.eql(i + 1);
               i++;
             });
 
-            function cb(value) {
+            function cb (value) {
               expect(value).to.eql(lastCbFired + 1);
               lastCbFired = value;
-              if (value == 3) {
+              if (value === 3) {
                 done();
               }
             }
 
             // 2 and 3 will be in the same payload
-            socket.once('flush', function() {
-              socket.send(2, function() { cb(2); });
-              socket.send(3, function() { cb(3); });
+            socket.once('flush', function () {
+              socket.send(2, function () { cb(2); });
+              socket.send(3, function () { cb(3); });
             });
 
-            socket.send(1, function() { cb(1); });
+            socket.send(1, function () { cb(1); });
           });
         });
       });
@@ -1786,33 +1779,33 @@ describe('server', function () {
           var i = 0;
           var lastCbFired = 0;
 
-          engine.on('connection', function(conn) {
-            conn.on('message', function(msg) {
+          engine.on('connection', function (conn) {
+            conn.on('message', function (msg) {
               conn.send(msg);
             });
           });
 
           socket.on('open', function () {
-            socket.on('message', function(msg) {
+            socket.on('message', function (msg) {
               expect(msg).to.eql(i + 1);
               i++;
             });
 
-            function cb(value) {
+            function cb (value) {
               expect(value).to.eql(lastCbFired + 1);
               lastCbFired = value;
-              if (value == 3) {
+              if (value === 3) {
                 done();
               }
             }
 
             // 2 and 3 will be in the same payload
-            socket.once('flush', function() {
-              socket.send(2, function() { cb(2); });
-              socket.send(3, function() { cb(3); });
+            socket.once('flush', function () {
+              socket.send(2, function () { cb(2); });
+              socket.send(3, function () { cb(3); });
             });
 
-            socket.send(1, function() { cb(1); });
+            socket.send(1, function () { cb(1); });
           });
         });
       });
@@ -1834,7 +1827,7 @@ describe('server', function () {
             });
           });
 
-          setTimeout(function() {
+          setTimeout(function () {
             expect(i).to.be(j);
             done();
           }, 100);
@@ -1882,11 +1875,11 @@ describe('server', function () {
 
           socket.on('open', function () {
             socket.on('message', function (msg) {
-              if (msg === 'a') a ++;
-              if (msg === 'b') b ++;
-              if (msg === 'c') c ++;
+              if (msg === 'a') a++;
+              if (msg === 'b') b++;
+              if (msg === 'c') c++;
 
-              if(++all === 3) {
+              if (++all === 3) {
                 expect(a).to.be(1);
                 expect(b).to.be(1);
                 expect(c).to.be(1);
@@ -1911,7 +1904,6 @@ describe('server', function () {
             conn.send('a', function (transport) {
               i++;
             });
-
           });
           socket.on('open', function () {
             socket.on('message', function (msg) {
@@ -1948,7 +1940,6 @@ describe('server', function () {
             conn.send('a', function (transport) {
               i++;
             });
-
           });
           socket.on('open', function () {
             socket.on('message', function (msg) {
@@ -1994,7 +1985,7 @@ describe('server', function () {
         var engine = listen({ allowUpgrades: false }, function (port) {
           var socket = new eioc.Socket('ws://localhost:%d'.s(port), { transports: ['polling'] });
 
-          socket.transport.on('pollComplete', function(msg) {
+          socket.transport.on('pollComplete', function (msg) {
             socket.close();
           });
 
@@ -2013,7 +2004,7 @@ describe('server', function () {
     });
   });
 
-  describe('packet', function() {
+  describe('packet', function () {
     it('should emit when socket receives packet', function (done) {
       var engine = listen({ allowUpgrades: false }, function (port) {
         var socket = new eioc.Socket('ws://localhost:%d'.s(port));
@@ -2032,7 +2023,7 @@ describe('server', function () {
 
     it('should emit when receives ping', function (done) {
       var engine = listen({ allowUpgrades: false, pingInterval: 4 }, function (port) {
-        var socket = new eioc.Socket('ws://localhost:%d'.s(port));
+        eioc('ws://localhost:%d'.s(port));
         engine.on('connection', function (conn) {
           conn.on('packet', function (packet) {
             conn.close();
@@ -2044,12 +2035,12 @@ describe('server', function () {
     });
   });
 
-  describe('packetCreate', function() {
+  describe('packetCreate', function () {
     it('should emit before socket send message', function (done) {
       var engine = listen({ allowUpgrades: false }, function (port) {
-        var socket = new eioc.Socket('ws://localhost:%d'.s(port));
+        eioc('ws://localhost:%d'.s(port));
         engine.on('connection', function (conn) {
-          conn.on('packetCreate', function(packet) {
+          conn.on('packetCreate', function (packet) {
             expect(packet.type).to.be('message');
             expect(packet.data).to.be('a');
             done();
@@ -2061,7 +2052,7 @@ describe('server', function () {
 
     it('should emit before send pong', function (done) {
       var engine = listen({ allowUpgrades: false, pingInterval: 4 }, function (port) {
-        var socket = new eioc.Socket('ws://localhost:%d'.s(port));
+        eioc('ws://localhost:%d'.s(port));
         engine.on('connection', function (conn) {
           conn.on('packetCreate', function (packet) {
             conn.close();
@@ -2077,7 +2068,8 @@ describe('server', function () {
     it('should upgrade', function (done) {
       var engine = listen(function (port) {
         // it takes both to send 50 to verify
-        var ready = 2, closed = 2;
+        var ready = 2;
+        var closed = 2;
         function finish () {
           setTimeout(function () {
             socket.close();
@@ -2086,11 +2078,13 @@ describe('server', function () {
 
         // server
         engine.on('connection', function (conn) {
-          var lastSent = 0, lastReceived = 0, upgraded = false;
+          var lastSent = 0;
+          var lastReceived = 0;
+          var upgraded = false;
           var interval = setInterval(function () {
             lastSent++;
             conn.send(lastSent);
-            if (50 == lastSent) {
+            if (50 === lastSent) {
               clearInterval(interval);
               --ready || finish();
             }
@@ -2123,11 +2117,13 @@ describe('server', function () {
         // client
         var socket = new eioc.Socket('ws://localhost:%d'.s(port));
         socket.on('open', function () {
-          var lastSent = 0, lastReceived = 0, upgrades = 0;
+          var lastSent = 0;
+          var lastReceived = 0;
+          var upgrades = 0;
           var interval = setInterval(function () {
             lastSent++;
             socket.send(lastSent);
-            if (50 == lastSent) {
+            if (50 === lastSent) {
               clearInterval(interval);
               --ready || finish();
             }
@@ -2163,7 +2159,7 @@ describe('server', function () {
       });
 
       // attach another engine to make sure it doesn't break upgrades
-      var e2 = eio.attach(engine.httpServer, { path: '/foo' });
+      eio.attach(engine.httpServer, { path: '/foo' });
     });
   });
 
@@ -2179,13 +2175,13 @@ describe('server', function () {
         http.get({
           port: port,
           path: '/engine.io/default/?transport=polling'
-        }, function(res) {
+        }, function (res) {
           var sid = res.headers['set-cookie'][0].split('=')[1];
           http.get({
             port: port,
             path: '/engine.io/default/?transport=polling&sid=' + sid,
             headers: { 'Accept-Encoding': 'gzip, deflate' }
-          }, function(res) {
+          }, function (res) {
             expect(res.headers['content-encoding']).to.equal('gzip');
             res.pipe(zlib.createGunzip())
               .on('error', done)
@@ -2207,13 +2203,13 @@ describe('server', function () {
         http.get({
           port: port,
           path: '/engine.io/default/?transport=polling'
-        }, function(res) {
+        }, function (res) {
           var sid = res.headers['set-cookie'][0].split('=')[1];
           http.get({
             port: port,
             path: '/engine.io/default/?transport=polling&sid=' + sid,
             headers: { 'Accept-Encoding': 'deflate' }
-          }, function(res) {
+          }, function (res) {
             expect(res.headers['content-encoding']).to.equal('deflate');
             res.pipe(zlib.createDeflate())
               .on('error', done)
@@ -2235,13 +2231,13 @@ describe('server', function () {
         http.get({
           port: port,
           path: '/engine.io/default/?transport=polling'
-        }, function(res) {
+        }, function (res) {
           var sid = res.headers['set-cookie'][0].split('=')[1];
           http.get({
             port: port,
             path: '/engine.io/default/?transport=polling&sid=' + sid,
             headers: { 'Accept-Encoding': 'gzip, deflate' }
-          }, function(res) {
+          }, function (res) {
             expect(res.headers['content-encoding']).to.equal('gzip');
             done();
           });
@@ -2260,13 +2256,13 @@ describe('server', function () {
         http.get({
           port: port,
           path: '/engine.io/default/?transport=polling'
-        }, function(res) {
+        }, function (res) {
           var sid = res.headers['set-cookie'][0].split('=')[1];
           http.get({
             port: port,
             path: '/engine.io/default/?transport=polling&sid=' + sid,
             headers: { 'Accept-Encoding': 'gzip, deflate' }
-          }, function(res) {
+          }, function (res) {
             expect(res.headers['content-encoding']).to.be(undefined);
             done();
           });
@@ -2285,13 +2281,13 @@ describe('server', function () {
         http.get({
           port: port,
           path: '/engine.io/default/?transport=polling'
-        }, function(res) {
+        }, function (res) {
           var sid = res.headers['set-cookie'][0].split('=')[1];
           http.get({
             port: port,
             path: '/engine.io/default/?transport=polling&sid=' + sid,
             headers: { 'Accept-Encoding': 'gzip, deflate' }
-          }, function(res) {
+          }, function (res) {
             expect(res.headers['content-encoding']).to.be(undefined);
             done();
           });
@@ -2310,13 +2306,13 @@ describe('server', function () {
         http.get({
           port: port,
           path: '/engine.io/default/?transport=polling'
-        }, function(res) {
+        }, function (res) {
           var sid = res.headers['set-cookie'][0].split('=')[1];
           http.get({
             port: port,
             path: '/engine.io/default/?transport=polling&sid=' + sid,
             headers: { 'Accept-Encoding': 'gzip, deflate' }
-          }, function(res) {
+          }, function (res) {
             expect(res.headers['content-encoding']).to.be(undefined);
             done();
           });
@@ -2333,7 +2329,7 @@ describe('server', function () {
         engine.on('connection', function (conn) {
           var socket = conn.transport.socket;
           var send = socket.send;
-          socket.send = function(data, opts, callback) {
+          socket.send = function (data, opts, callback) {
             socket.send = send;
             socket.send(data, opts, callback);
 
@@ -2346,7 +2342,7 @@ describe('server', function () {
           for (var i = 0; i < buf.length; i++) buf[i] = i % 0xff;
           conn.send(buf, { compress: true });
         });
-        new eioc.Socket('http://localhost:%d'.s(port), { transports: ['websocket'] });
+        eioc('http://localhost:%d'.s(port), { transports: ['websocket'] });
       });
     });
 
@@ -2355,7 +2351,7 @@ describe('server', function () {
         engine.on('connection', function (conn) {
           var socket = conn.transport.socket;
           var send = socket.send;
-          socket.send = function(data, opts, callback) {
+          socket.send = function (data, opts, callback) {
             socket.send = send;
             socket.send(data, opts, callback);
 
@@ -2368,7 +2364,7 @@ describe('server', function () {
           for (var i = 0; i < buf.length; i++) buf[i] = i % 0xff;
           conn.send(buf, { compress: true });
         });
-        new eioc.Socket('http://localhost:%d'.s(port), { transports: ['websocket'] });
+        eioc('http://localhost:%d'.s(port), { transports: ['websocket'] });
       });
     });
   });
@@ -2381,7 +2377,7 @@ describe('server', function () {
       'cookie': 'user_session=NI2JlCKF90aE0sJZD9ZzujtdsUqNYSBYxzlTsvdSUe35ZzdtVRGqYFr0kdGxbfc5gUOkR9RGp20GVKza; path=/; expires=Tue, 07-Apr-2015 18:18:08 GMT; secure; HttpOnly'
     };
 
-    function testForTransport(transport, done) {
+    function testForTransport (transport, done) {
       var engine = listen(function (port) {
         var socket = new eioc.Socket('ws://localhost:%d'.s(port), {
           extraHeaders: headers,
@@ -2407,17 +2403,17 @@ describe('server', function () {
   });
 
   describe('response headers', function () {
-    function testForHeaders(headers, done) {
+    function testForHeaders (headers, done) {
       var engine = listen(function (port) {
         engine.on('connection', function (conn) {
-          conn.transport.once('headers', function(headers) {
+          conn.transport.once('headers', function (headers) {
             expect(headers['X-XSS-Protection']).to.be('0');
             conn.close();
             done();
           });
           conn.send('hi');
         });
-        new eioc.Socket('ws://localhost:%d'.s(port), {
+        eioc('ws://localhost:%d'.s(port), {
           extraHeaders: headers,
           transports: ['polling']
         });
@@ -2435,21 +2431,23 @@ describe('server', function () {
     });
   });
 
-  if (!UWS_ENGINE && parseInt(process.versions.node) >= 4) describe('wsEngine option', function() {
-    it('should allow loading of other websocket server implementation like uws', function(done) {
-      var engine = listen({ allowUpgrades: false, wsEngine: 'uws' }, function (port) {
-        expect(engine.ws instanceof require('uws').Server).to.be.ok();
-        var socket = new eioc.Socket('ws://localhost:%d'.s(port));
-        engine.on('connection', function (conn) {
-          conn.send('a');
-        });
-        socket.on('open', function () {
-          socket.on('message', function (msg) {
-            expect(msg).to.be('a');
-            done();
+  if (!UWS_ENGINE && parseInt(process.versions.node, 10) >= 4) {
+    describe('wsEngine option', function () {
+      it('should allow loading of other websocket server implementation like uws', function (done) {
+        var engine = listen({ allowUpgrades: false, wsEngine: 'uws' }, function (port) {
+          expect(engine.ws instanceof require('uws').Server).to.be.ok();
+          var socket = new eioc.Socket('ws://localhost:%d'.s(port));
+          engine.on('connection', function (conn) {
+            conn.send('a');
+          });
+          socket.on('open', function () {
+            socket.on('message', function (msg) {
+              expect(msg).to.be('a');
+              done();
+            });
           });
         });
       });
     });
-  });
+  }
 });