Expressjs & EJS Tutorial to Choose and Upload File-Nodejs complete code

app.js

const express = require('express');
const bodyParser = require('body-parser');
const path = require('path');
const formidable = require('formidable');
const fs = require('fs');
const app = express();
const port = 3000;
// configure middleware
app.set('port', process.env.port || port); // set express to use this port
app.set('views', __dirname + '/views'); // set express to look in this folder to render our view
app.set('view engine', 'ejs'); // configure template engine
app.use(bodyParser.urlencoded({ extended: false }));
app.use(bodyParser.json()); // parse form data client
app.use(express.static(path.join(__dirname, 'public'))); // configure express to use public folder
// set the app to listen on the port

//upload file api
app.post('/uploadfile',upload_file);
app.get('/', open_index_page);//call for main index page

app.listen(port, () => {
    console.log(`Server running on port: ${port}`);
});

function upload_file(req, res, next){
   if(req.method == "POST") {
      // create an incoming form object
      var form = new formidable.IncomingForm();
      // specify that we want to allow the user to upload multiple files in a single request
      form.multiples = true;
      // store all uploads in the /uploads directory
      form.uploadDir = path.basename(path.dirname('/uploads/json_files/'))
      // every time a file has been uploaded successfully,
      // rename it to it's orignal name
      form.on('file', function(field, file) {
        fs.rename(file.path, path.join(form.uploadDir, file.name), function(err){
            if (err) throw err;
            //console.log('renamed complete: '+file.name);
            const file_path = '/uploads/'+file.name
        });
      });
      // log any errors that occur
      form.on('error', function(err) {
          console.log('An error has occured: \n' + err);
      });
      // once all the files have been uploaded, send a response to the client
      form.on('end', function() {
           //res.end('success');
           res.statusMessage = "Process cashabck initiated";
           res.statusCode = 200;
           res.redirect('/')
           res.end()
      });
      // parse the incoming request containing the form data
      form.parse(req);
    }
}

function open_index_page(req, res, next){

  if(req.method == "GET"){
       res.render('index.ejs');
   }
}