socket.io emit question : How does an io emit itself?

Question

I want to use the emit event in the express router, so I am trying to pass a global.io.

But the problem is, even if I add this code

io.emit('join','Tudis')

in the server.js, I can't see any response output,

(I think there should be 'someone joined:Tudis' right after compiling?) please enlighten me, thank you so much.

-----the code of server.js---------

const express = require('express')
const socketio=require('socket.io')
const http=require('http')

const serverPORT=5000

const app = express();
const server = http.createServer(app)
const io=socketio(server)

io.on('connection',(socket)=>{   
  socket.on('join',(name)=>{
    console.log('someone joined :' + name)
  }) 
})

global.io=io
const router=require('./router')
app.use(router)

io.emit('join','Tudis')

server.listen(serverPORT,
  ()=> console.log('server is up at : '+serverPORT)
  )

Answer 1

I found my answer.... thank you all !! I am really so happy !!

Node.js client for a socket.io server

//client.js
var io = require('socket.io-client');
var socket = io.connect('http://localhost:3000', {reconnect: true});
socket.emit('CH01', 'me', 'test msg');

after such a long way of studying...feeling pretty exhausted but I think I can finally start to build something XD

Thank you!!!!!

(by the way before I choose this way, I was actually using the puppeteer to visit the website to send the emit..

lol it 'worked' though)