Possibility to disable JSONP. Emitting an error if JSONP is the only available transport.

test/connection.js

@@ -1,6 +1,12 @@
 var expect = require('expect.js');
 var eio = require('../');
 
+var wsSupport = require('has-cors');
+var uagent = navigator.userAgent;
+var isOldSimulator = ~uagent.indexOf('iPhone OS 4') || ~uagent.indexOf('iPhone OS 5');
+var isIE11 = !!navigator.userAgent.match(/Trident.*rv[ :]*11\./); // ws doesn't work at all in sauce labs
+var isAndroid = navigator.userAgent.match(/Android/i);
+
 describe('connection', function() {
   this.timeout(20000);
 
@@ -55,7 +61,7 @@ describe('connection', function() {
       }, 1200);
     });
   });
-    
+
   // no `Worker` on old IE
   if (global.Worker) {
     it('should work in a worker', function(done){
@@ -66,4 +72,23 @@ describe('connection', function() {
       };
     });
   }
+
+  it('should not connect at all when JSONP forced and disabled', function(done) {
+    var socket = eio.Socket({ transports: ['polling'], forceJSONP: true, noJSONP: true });
+    socket.on('error', function(msg) {
+      expect(msg).to.be('No transports available');
+      done();
+    });
+  });
+
+  if (wsSupport && !isOldSimulator && !isAndroid && !isIE11) {
+    it('should connect with ws when JSONP forced and disabled', function(done) {
+      var socket = eio.Socket({ transports: ['polling', 'websocket'], forceJSONP: true, noJSONP: true });
+
+      socket.on('open', function() {
+        expect(socket.transport.name).to.be('websocket');
+        done();
+      });
+    });
+  }
 });