proxy-test.js

var http = require('http');
var httpProxy = require('http-proxy');
var request = require('supertest');

var proxied = http.createServer(function (req, res) {
  console.log('proxied: request received');
  res.writeHead(200, { 'Content-Type': 'text/plain' });
  res.end('okay');
});

proxied.listen(3001);

var proxy = httpProxy.createProxyServer({
  target: 'http://localhost:3001/',
});

var mainServer = http.createServer(function(req, res) {
  console.log('main: request received');
  proxy.web(req, res);
});

mainServer.listen(1337);

request(mainServer)
  .delete('/api/get')
  .set('accept', 'text/json')
  .end(function(err) {
    console.log('request finished (err=' + err + ')');

    mainServer.close();
    proxied.close();
  });