Using a PAC file for all HTTP requests in hubot

hubot-http-proxy.js

/* from package.json
  "dependencies": {
    "pac-proxy-agent": "~0.2.0",
    "scoped-http-client": "~0.10.0"
  }
*/

var url = require('url');
var http = require('http');
var https = require('https');
var HttpClient = require('scoped-http-client');
var PacProxyAgent = require('pac-proxy-agent');

var agentOpts;

// URI to a PAC proxy file to use (the "pac+" prefix is stripped)
var proxy = 'pac+http://my-proxy-host/proxy.pac';

// create an instance of the `PacProxyAgent` class with the PAC file location
agentOpts = url.parse(proxy);
agentOpts.secureEndpoint = true;
var httpsAgent = new PacProxyAgent(agentOpts);

agentOpts = url.parse(proxy);
agentOpts.secureEndpoint = false;
var httpAgent = new PacProxyAgent(agentOpts);

var scopedHttpClient = function (providedUrl) {
  var httpClient;
  if (url.parse(providedUrl, true).protocol == 'https:') {
    httpClient = HttpClient.create(providedUrl, {agent: httpsAgent});
  } else {
    httpClient = HttpClient.create(providedUrl, {agent: httpAgent});
  }
  return httpClient;
};

module.exports = (robot) ->
  robot.http = (url) ->
    scopedHttpClient(url).header('User-Agent', "Hubot/#{robot.version}");