HTTP Sniffer – listening to the HTTP conversation

The events emitted by the HTTPServer object can be used for additional purposes beyond the immediate task of delivering a web application. The following code demonstrates a useful module that listens to all of the HTTPServer events. It could be a useful debugging tool, which also demonstrates how HTTPServer objects operate.

Node.js's HTTPServer object is an EventEmitter object, and HTTP Sniffer simply listens to every server event, printing out information pertinent to each event.

Create a file named httpsniffer.mjs, containing the following code:

import * as util from 'util';
import * as url from 'url';

const timestamp = () => { return new Date().toISOString(); }

export function sniffOn(server) {
    server.on('request', (req, res) => {
        console.log(`${timestamp()} request`);
        console.log(`${timestamp()} ${reqToString(req)}`);
    });

    server.on('close', errno => {...