I am writing a server for my realtime collab IDE and this is my backend, Here is the full backend index.js code

const express = require("express");
const app = express();
const http = require('http');
const {Server} = require('socket.io');

const server = http.createServer(app);
const io = new Server(server);

const userSocketMap = {};

const getAllConnectedClients = (roomId) => {
    return Array.from(io.sockets.adapter.rooms.get(rommId) || []).map(
        (socketId) =>{
            return{
                socketId,
                username: userSocketMap[socketId],
            };
        }
    ) //map
};

io.on("connection", (socket) => {
    //console.log(`User connected: ${socket.id}`);
    socket.on("join", ({ roomId, username }) => {
        userSocketMap[socket.id] = username;
        socket.join(roomId);
        const clients = getAllConnectedClients(roomId);
        console.log(clients);
    });
});

const PORT = process.nextTick.PORT || 5000;
server.listen(PORT, () => console.log('server is running'));

Here this area is constantly crashing node.js

    socket.on("join", ({ roomId, username }) => {
        userSocketMap[socket.id] = username;
        socket.join(roomId);
        const clients = getAllConnectedClients(roomId);
        console.log(clients);

I tried re-importing almost everything but it didnt help