discover rooms for a given socket.io connection

rooms.js

function findRooms() {
    var availableRooms = [];
    var rooms = io.sockets.adapter.rooms;
    if (rooms) {
        for (var room in rooms) {
            if (!rooms[room].hasOwnProperty(room)) {
                availableRooms.push(room);
            }
        }
    }
    return availableRooms;
}