Basic HTTP proxy that introduces random delays to responses, to help test network race conditions

proxy.js

#!/usr/bin/env node

/**
 * INSTRUCTIONS
 *
 *  npm install http-proxy
 *  node proxy.js
 */

var config = {
    // Port to access this proxy
    proxyPort: 2991,
    // Port of the real server
    targetPort: 2990,
    // Min/max values for request delays, in milliseconds
    timeRange: [0, 3000]
};

var http = require('http'),
    httpProxy = require('http-proxy');

function randomTime() {
    var min = config.timeRange[0],
        max = config.timeRange[1];
    return (Math.random() * (max - min) + min) | 0;
}

httpProxy.createServer(function (req, res, proxy) {
    var buffer = httpProxy.buffer(req),
        time = randomTime();
    console.log(req.method + ' ' + req.url);

    setTimeout((function (time) {
        return function () {
            console.log('SERVE ' + req.url + ' (' + time + 'ms delay)');
            proxy.proxyRequest(req, res, {
                host: 'localhost',
                port: config.targetPort,
                buffer: buffer
            });
        };
    })(time), time);
}).listen(config.proxyPort);