Not calling next on io.of('/test') middleware does not timeout or error

In the following code server side:

io.of('/test').use(function(socket, next){
  console.log("Authenticating...")
  //next();
});

A socket.io connecting to the /test namespace will never connect (obviously), but it will never either get a timeout or error, it will just be in a pre-connection state for ever. Seems like an innocuous bug but its not, in my example next is not called explicitly, but if the code before next throws an exception for example you will get the same result on the client side.

Start by reproducing the server-side io.of('/test').use middleware example and observe the client when next is never called or middleware code throws. Trace the namespace middleware connection path and add coverage for the expected timeout or error behavior, then verify that the client no longer remains in a pre-connection state indefinitely.