return the original or redirected URL (if there was a redirect)

https://developer.mozilla.org/en-US/docs/Web/API/XMLHttpRequest/responseURL

Author: maxgalbu

lib/XMLHttpRequest.js

@@ -109,6 +109,7 @@ exports.XMLHttpRequest = function() {
   // Result & response
   this.responseText = "";
   this.responseXML = "";
+  this.responseURL = "";
   this.status = null;
   this.statusText = null;
 
@@ -169,6 +170,8 @@ exports.XMLHttpRequest = function() {
       "user": user || null,
       "password": password || null
     };
+    
+    this.responseUrl = url;
 
     setState(this.OPENED);
   };
@@ -408,7 +411,7 @@ exports.XMLHttpRequest = function() {
         // @TODO Prevent looped redirects
         if (response.statusCode === 301 || response.statusCode === 302 || response.statusCode === 303 || response.statusCode === 307) {
           // Change URL to the redirect location
-          settings.url = response.headers.location;
+          self.responseUrl = settings.url = response.headers.location;
           var url = Url.parse(settings.url);
           // Set host var in case it's used later
           host = url.hostname;