socket.io emit to default room does not work - socket.io

Question

When I call emit without the io.emit() all the connected clients receive the message as you would expect. However when trying to send a message to the default room using io.to(socket.id).emit(), the client does not receive the message.
Refering to default room documentation at
http://socket.io/docs/rooms-and-namespaces/#default-room
Using nodejs v4.2.6
Client:
var socket = io();
socket.on('connect', function() {
$.ajax({
url: '/some-path',
type: 'POST',
data: {socket_id: socket.id},
success: function(data) {
console.log(data);
}
});
});
Server:
app.post('/some-path', function(req, res) {
var socketID = req.body.socket_id;
io.to(socketID).emit('message', {'message': socketID});
res.end(socketID);
});

Answer 1

This is the correct solution. It was discovered that the default room socket.id being used by the server to set the default room is not the same as the client socket.id. Please advise.
On the client if you evaluate socket.id you get something like, v4eEdSX5RnDSXjzuAAAA
On the server in, io.on('connection', function(socket){}) if you evaluate socket.id you will get something like, /#v4eEdSX5RnDSXjzuAAAA.
Notice the /# prepended to the client socket.id.
So you have two ways of solving this issue
When calling emit prepend /# to the socket ID
Override the io "connection" listener to set the room to the socket ID without the /# prepended
Selected option two is as follows:
io.on('connection', function(socket) {
socketID = socket.client.id;
socket.join(socketID);
console.log('a user connected ' + socketID);
});