Socket.io (emit, on) not working - Node JS - node.js

Question

I am working on a node JS application, where I am trying to use socket.io following this tutorial. Until this tutorial everything is fine, even the client is connected to the server through the socket, as it display a message on connection. But I don't know why my code isn't working on emit, and on event, and event handler.
Below is my Code on server side :
const express = require("express");
const app = express();
const scrap = require("./algorithm");
const mysql = require("mysql");
const ms_connect = mysql.createConnection({
host:'localhost',
user:'root',
password:'',
database:'scrapper_db'
});
const server = app.listen(8000, function(){ console.log('Listening on 8000'); });
const io = require("socket.io").listen(server);
app.use(express.static(__dirname + "/"));
io.on("connection",function(socket){
console.log("Sockets Connection Made ! " + socket.id);
socket.emit("testing",{data:"I am tested"});
io.on("disconnect",function(){
console.log("Client Disconnected !");
})
})
//mySQL Conection
ms_connect.connect(function(err){
if(err) console.log(err);
ms_connect.query("Select * FROM test",function(err,rows,fields){
if(err) console.log("Error Executing Query");
})
})
app.get("/scrap",function(req,res){
res.sendFile(__dirname+"/index.html");
})
Client side code :
var socket = io.connect('http://localhost:8000/scrap');
console.log(socket.connected); //returns false :(
socket.on("testing", function(d) {
console.log(d);
});
In the client side, the socket.connected object returns false, but on server side it says connected. I don't know how , and
I am using third link from this socket.io cdnjs server.

Answer 1

You are doing io.connect('http://localhost:8000/scrap') but the scrap is not mentioned anywhere on the server side. It should be io.connect('http://localhost:8000/'). Pointing to your HTML file is not needed because the socket.io server and your webserver are unrelated.
Also as pointed out by #TommyBs you should use
socket.on('connect', () => { console.log(socket.connected); });
to check if you are connected because connecting is asynchronous so it will not have connected yet by the time you do console.log(socket.connected);
The whole client code would be
var socket = io.connect('http://localhost:8000');
socket.on('connect', () => { console.log(socket.connected); });
socket.on("testing", function(d) {
console.log(d);
});

Answer 2

Change http://localhost:8000/scrap to http://localhost:8000/ in the client code. You're connecting to the wrong route.