Minimal HTTP server using vanilla JavaScript

server.js

'use strict';

import { createServer } from 'node:http';

/*
 * Usage:
 * node server.js
 * 
 * This will pick a random available port on your local machine. You can steer the port and host using environment variables:
 * PORT=8080 HOST=localhost node server.js
 *
 * During development you can use `--watch` to automatically restart the server on code change. When using this I recommend
 * specifying a port, otherwise the hot reload will likely pick another port.
 */

const port = process.env.PORT ? parseInt(process.env.PORT, 10) : undefined;
const host = process.env.HOST ?? '0.0.0.0';

/**
 * @param {import('node:http').IncomingMessage} request
 * @param {import('node:http').ServerResponse} response
 * @return {Promise<void>}
 */
const handler = async (request, response) => {
    console.debug('incoming request', request.url);

    let payload = '';
    request.on('data', (chunk) => { payload += chunk; });

    request.on('end', () => {
        console.debug('received data', payload);
      
        /*
         * This is where the request is handled. Any routing should be done in here as well.
         */
      
        response.writeHead(200, {'Content-Type': 'text/plain'});
        response.write('OK');
        response.end();
    });
}

const server = createServer(handler);

server.listen(port, host, () => {
    console.log(`Listening on port http://${server.address().address}:${server.address().port}`);
});