SocketIO ERR_CONNECTION_REFUSED

I faced exactly the same issue. I did not see the ERR_CONNECTION_REFUSED in socket.io@~0.9. The error surfaced after I upgraded socket.io to 1.3.

I solved it by simply removing the URL from the client side constructor:

Change

var socket = io('http://localhost');

To

var socket = io();  

As the socket.io tutorial showed: http://socket.io/get-started/chat/