httpuppercaser.js

var http = require('http');

var server = http.createServer(function (req, res) { 
    var body = "";
    res.writeHead(200, { 'content-type': 'text/plain' });
    if(req.method != 'POST') {
        return res.end('Please send a POST\n')
    }

    req.on('data', (data) => {
        body += data.toString();
       
    });
    req.on('end', () => {
       res.end(body.toUpperCase());
    })

});
server.listen(process.argv[2]);