[chore] Revert to ws as default wsEngine (#550)

Related:
- socketio/socket.io#2956
- socketio/socket.io#3100

Fixes #536
Fixes #516
Fixes #474

README.md

@@ -226,7 +226,7 @@ to a single process.
         option. If false, no path will be sent, which means browsers will only send the cookie on the engine.io attached path (`/engine.io`).
         Set false to not save io cookie on all requests. (`/`)
       - `cookieHttpOnly` (`Boolean`): If `true` HttpOnly io cookie cannot be accessed by client-side APIs, such as JavaScript. (`true`) _This option has no effect if `cookie` or `cookiePath` is set to `false`._
-      - `wsEngine` (`String`): what WebSocket server implementation to use. Specified module must conform to the `ws` interface (see [ws module api docs](https://github.com/websockets/ws/blob/master/doc/ws.md)). Default value is `uws` (see [µWebSockets](https://github.com/uWebSockets/uWebSockets)).
+      - `wsEngine` (`String`): what WebSocket server implementation to use. Specified module must conform to the `ws` interface (see [ws module api docs](https://github.com/websockets/ws/blob/master/doc/ws.md)). Default value is `ws`. An alternative c++ addon is also available by installing `uws` module.
       - `initialPacket` (`Object`): an optional packet which will be concatenated to the handshake packet emitted by Engine.IO.
 - `close`
     - Closes all clients

lib/server.js

@@ -36,7 +36,7 @@ function Server (opts) {
 
   opts = opts || {};
 
-  this.wsEngine = opts.wsEngine || process.env.EIO_WS_ENGINE || 'uws';
+  this.wsEngine = opts.wsEngine || process.env.EIO_WS_ENGINE || 'ws';
   this.pingTimeout = opts.pingTimeout || 60000;
   this.pingInterval = opts.pingInterval || 25000;
   this.upgradeTimeout = opts.upgradeTimeout || 10000;
@@ -103,16 +103,10 @@ Server.prototype.init = function () {
   if (this.ws) this.ws.close();
 
   var wsModule;
-  try {
-    switch (this.wsEngine) {
-      case 'uws': wsModule = require('uws'); break;
-      case 'ws': wsModule = require('ws'); break;
-      default: throw new Error('unknown wsEngine');
-    }
-  } catch (ex) {
-    this.wsEngine = 'ws';
-    // keep require('ws') as separate expression for packers (browserify, etc)
-    wsModule = require('ws');
+  switch (this.wsEngine) {
+    case 'uws': wsModule = require('uws'); break;
+    case 'ws': wsModule = require('ws'); break;
+    default: throw new Error('unknown wsEngine');
   }
   this.ws = new wsModule.Server({
     noServer: true,

package.json

@@ -45,14 +45,12 @@
     "expect.js": "^0.3.1",
     "mocha": "^4.0.1",
     "s": "0.1.1",
-    "superagent": "^3.8.1"
-  },
-  "optionalDependencies": {
+    "superagent": "^3.8.1",
     "uws": "~9.14.0"
   },
   "scripts": {
     "lint": "eslint lib/ test/ *.js",
-    "test": "npm run lint && mocha && EIO_WS_ENGINE=ws mocha"
+    "test": "npm run lint && mocha && EIO_WS_ENGINE=uws mocha"
   },
   "repository": {
     "type": "git",