Mongodb is not connecting to Node.js and no error messages

I'm new to Node.js and MongoDB. I installed all packages as specified in a YouTube tutorial. I tried a lot to connect MongoDB with Node.js, but there is no error messages and it is not connected. I have downloaded Mongo Shell as well. Everything works perfectly, the connection message is not displayed. It works on my command prompt, but not in vs code. I'm creating a sample project with Express generator. What's wrong with my code?

Here is my code:

var express = require('express');
var router = express.Router();
var MongoClient = require('mongodb').MongoClient


/* GET home page. */
router.get('/', function(req, res, next) {
  res.render('index', { title: 'Express' });
});

router.post('/signup', function(req, res) {
  console.log(req.body);


  MongoClient.connect('mongodb://localhost:27017', function(err, client){
    if(err)
      console.log('error')
    else
      console.log('mongodb connected...')
  })

  
  res.send('Got it.')
})

Solution

Try my simple code below, if it works, it says "Connected successfully to server" in the console log. It is only the first step.

//const { MongoClient } = require('mongodb');
// or as an es module:
import { MongoClient } from 'mongodb'

// Connection URL
const url = 'mongodb://localhost:27017';
const client = new MongoClient(url);

// Database Name
const dbName = 'myProject';

async function main() {
    // Use connect method to connect to the server
    await client.connect();
    console.log('Connected successfully to server');
    const db = client.db(dbName);
    const collection = db.collection('documents');

   
    return 'done.';
}

main()
    .then(console.log)
    .catch(console.error)
    .finally(() => client.close());

Try to install the mongodb driver again using this file package.json content:

 {
  "name": "mongodb",
  "version": "1.0.0",
  "description": "",
  "main": "mongodbsort.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "keywords": [],
  "author": "",
  "license": "ISC",
  "type": "module",
  "dependencies": {
    "mongodb": "^4.17.2"    
  }
}

the row "type": "module", is important