node js - handle form and get json value

// By: facebook.com/muhammad.sukron.52

/*
| result will be JSON format
| visit http://pastebin.com/uNbmC5MW to get form.html
| to test with another method use app http://www.getpostman.com/
*/

var http = require('http');

//to read file
var fs = require('fs');

//to handle form. install package required
var formidable = require('formidable');

var util = require('util');

var server = http.createServer(function(req, res) {
    if(req.url == '/') {
        switch(req.method) {
            case 'GET':
                set_form(res);
                break;

            case 'POST':
                process_form(req, res);
                break;

            default:
                res.end('method not permitted');
                break;
        }
    }
});

function set_form(res) {
    fs.readFile('form.html', function(err, data) {
        res.writeHead(200, {
            'Content-length' : data.length,
            'Content-type' : 'Text/HTML',
            'Content-header' : 'Learn Node JS'
        });
        res.write(data);
        res.end();
    });
}

function process_form(req, res) {
    var form = new formidable.IncomingForm();

    form.parse(req, function(err, fields, files) {
        //combine object fields and files
        var result = Object.assign(fields, files);

        res.end(JSON.stringify(result));
    });
}

server.listen(3400);
console.log('server is running');