a really dumb quick node.js proxy to introduce artificial latency to a local port

latent.js

// node latent.js fromport toport delay
// where fromport is the port of the service and toport is the port to serve the proxy on

const { createServer, request } = require('http');

const [ , , fromport, toport, delaystr = 1000 ] = process.argv;
const delay = parseInt(delaystr);

createServer((req, res) => {
  setTimeout(() => {
    const prox = request({
      hostname: 'localhost',
      port: fromport,
      path: req.url,
      method: req.method,
      headers: req.headers
    }, (pres) => {
      res.writeHead(pres.statusCode, pres.headers);
      pres.pipe(res, { end: true });
    });
    req.pipe(prox, { end: true });
  }, delay);
}).listen(toport);