socket.io random chatroom one to one - node.js

Question

so there is my code i am trying to create chatroom with Socket.io with rooms (one-to-one random chatroom) but i think there is bug because when i connect first two sockets it works perfectly but when i connect third socket it does not work anymore i think it is because of "numb++" but i don't know how to correct it because i have not many experience in rooms. i wanna implement : chat between 2 socket and when third client joins i wanna create second room and wait for forth socket to join to chat and etc. , and u i know i wanna one to one random chatroom like Omegle.
var numb = 1;
var chnm = io.of('/STchat')
app.get('/STchat', function(req, res){
res.sendFile('C:\\Users\\tuna\\Desktop\\JUSTFOL\\views\\Tchat.html')
chnm.once('connect', function(socket){
socket.join("room" + numb)
console.log('made socket connection', socket.id);
chnm.in("room" + numb).clients(function(err, clients){
if(clients.length > 2) {
numb++
}
});
socket.on('chat', function(data) {
chnm.in("room" + numb).emit('chat',data)
})
socket.on('disconnect', function(){
console.log('socket disconnected')
});
}
});
app.get('/StvChat', function(req ,res){
res.sendFile(__dirname + '/views/VideoC.html');
});
var socket = io.connect('http://localhost:5000/STchat')
var message = document.getElementById('message');
handle = document.getElementById('handle');
btn = document.getElementById('send');
output = document.getElementById('output');
typing = document.createElement('p');
typing.className = "tycl";
input = document.getElementById("message");
$('form').submit(function(){
socket.emit('chat',{
message: message.value,
});
$('#message').val('');
return false;
});
input.addEventListener("keyup", function(event) {
event.preventDefault();
if (event.keyCode === 13) {
document.getElementById("send").click();
}
});
socket.on('chat', function(data){
output.innerHTML += '<p>' +' '+ data.message +'</p>'
});

Answer 1

This was too long to fit in the comments so I have added as an answer. To clarify, here is an issue I am seeing in the way you are emitting the chat event. Lets walk through a scenario.
var numb = 1;
Two users (User A, and User B) connect to the socket and are put into room "room1". Now, numb should be incremented by your code and now numb will be == 2.
Now, User A (who is in "room1") emits a "chat" event. Here is the issue I see:
socket.on('chat', function(data) {
chnm.in("room" + numb).emit('chat', data)
})
User A's chat event is emitted to "room2" but User A is in "room1". This happens because numb == 2 at this point in the scenario and you are using numb to emit that event, basically this is what happens chnm.in("room" + 2). User B does not get User A's emit, because it was sent to the wrong room (room2). If I misunderstood what you are trying to do please let me know.
EDIT: As requested here is some modifications to your code that I have tested locally with success. Two users per each room.
var numb = 1;
var chnm = io.of('/STchat');
app.get('/STchat', function(req, res) {
res.sendFile('C:\\Users\\tuna\\Desktop\\JUSTFOL\\views\\Tchat.html');
chnm.once('connect', function(socket) {
// store the room in a var for convenience
var room = "room" + numb;
// join socket to the next open room
socket.join(room);
// store room on socket obj for use later - IMPORTANT
socket.current_room = room;
// log some stuff for testing
console.log('made socket connection', socket.id);
console.log("Joined room: ", socket.current_room);
// Check room occupancy, increment if 2 or more
chnm.in(room).clients(function(err, clients) {
if (clients.length >= 2) {
numb++;
}
});
socket.on('chat', function(data) {
// emit to that sockets room, now we use that current_room
chnm.in(socket.current_room).emit('chat', data);
});
socket.on('disconnect', function() {
console.log('socket disconnected');
});
});
});
app.get('/StvChat', function(req, res) {
res.sendFile(__dirname + '/views/VideoC.html');
});