fix(http): return URL in Response

Attach reponseURL or X-Request-URL to Response.

Closes  #5165

modules/angular2/src/http/backends/jsonp_backend.ts

@@ -57,7 +57,7 @@ export class JSONPConnection_ extends JSONPConnection {
         _dom.cleanup(script);
         if (!this._finished) {
           let responseOptions =
-              new ResponseOptions({body: JSONP_ERR_NO_CALLBACK, type: ResponseTypes.Error});
+              new ResponseOptions({body: JSONP_ERR_NO_CALLBACK, type: ResponseTypes.Error, url});
           if (isPresent(baseResponseOptions)) {
             responseOptions = baseResponseOptions.merge(responseOptions);
           }
@@ -65,7 +65,7 @@ export class JSONPConnection_ extends JSONPConnection {
           return;
         }
 
-        let responseOptions = new ResponseOptions({body: this._responseData});
+        let responseOptions = new ResponseOptions({body: this._responseData, url});
         if (isPresent(this.baseResponseOptions)) {
           responseOptions = this.baseResponseOptions.merge(responseOptions);
         }

modules/angular2/src/http/backends/xhr_backend.ts

@@ -8,7 +8,7 @@ import {Injectable} from 'angular2/angular2';
 import {BrowserXhr} from './browser_xhr';
 import {isPresent} from 'angular2/src/facade/lang';
 import {Observable} from 'angular2/angular2';
-import {isSuccess} from '../http_utils';
+import {isSuccess, getResponseURL} from '../http_utils';
 /**
 * Creates connections using `XMLHttpRequest`. Given a fully-qualified
 * request, an `XHRConnection` will immediately create an `XMLHttpRequest` object and send the
@@ -39,6 +39,8 @@ export class XHRConnection implements Connection {
 
         let headers = Headers.fromResponseHeaderString(_xhr.getAllResponseHeaders());
 
+        let url = getResponseURL(_xhr);
+
         // normalize IE9 bug (http://bugs.jquery.com/ticket/1450)
         let status: number = _xhr.status === 1223 ? 204 : _xhr.status;
 
@@ -48,7 +50,7 @@ export class XHRConnection implements Connection {
         if (status === 0) {
           status = body ? 200 : 0;
         }
-        var responseOptions = new ResponseOptions({body, status, headers});
+        var responseOptions = new ResponseOptions({body, status, headers, url});
         if (isPresent(baseResponseOptions)) {
           responseOptions = baseResponseOptions.merge(responseOptions);
         }

modules/angular2/src/http/http_utils.ts

@@ -17,4 +17,14 @@ export function normalizeMethodName(method): RequestMethods {
 
 export const isSuccess = (status: number): boolean => (status >= 200 && status < 300);
 
+export function getResponseURL(xhr: any): string {
+  if ('responseURL' in xhr) {
+    return xhr.responseURL;
+  }
+  if (/^X-Request-URL:/m.test(xhr.getAllResponseHeaders())) {
+    return xhr.getResponseHeader('X-Request-URL');
+  }
+  return;
+}
+
 export {isJsObject} from 'angular2/src/facade/lang';

modules/angular2/test/http/backends/xhr_backend_spec.ts

@@ -41,6 +41,7 @@ class MockBrowserXHR extends BrowserXhr {
   callbacks = new Map<string, Function>();
   status: number;
   responseHeaders: string;
+  responseURL: string;
   constructor() {
     super();
     var spy = new SpyObject();
@@ -56,10 +57,14 @@ class MockBrowserXHR extends BrowserXhr {
 
   setResponseText(value) { this.responseText = value; }
 
+  setResponseURL(value) { this.responseURL = value; }
+
   setResponseHeaders(value) { this.responseHeaders = value; }
 
   getAllResponseHeaders() { return this.responseHeaders || ''; }
 
+  getResponseHeader(key) { return Headers.fromResponseHeaderString(this.responseHeaders).get(key); }
+
   addEventListener(type: string, cb: Function) { this.callbacks.set(type, cb); }
 
   removeEventListener(type: string, cb: Function) { this.callbacks.delete(type); }
@@ -285,6 +290,39 @@ export function main() {
            existingXHRs[0].setStatusCode(statusCode);
            existingXHRs[0].dispatchEvent('load');
          }));
+
+      it('should add the responseURL to the response', inject([AsyncTestCompleter], async => {
+           var statusCode = 200;
+           var connection = new XHRConnection(sampleRequest, new MockBrowserXHR(),
+                                              new ResponseOptions({status: statusCode}));
+
+           connection.response.subscribe(res => {
+             expect(res.url).toEqual('http://google.com');
+             async.done();
+           });
+
+           existingXHRs[0].setResponseURL('http://google.com');
+           existingXHRs[0].setStatusCode(statusCode);
+           existingXHRs[0].dispatchEvent('load');
+         }));
+
+      it('should add use the X-Request-URL in CORS situations',
+         inject([AsyncTestCompleter], async => {
+           var statusCode = 200;
+           var connection = new XHRConnection(sampleRequest, new MockBrowserXHR(),
+                                              new ResponseOptions({status: statusCode}));
+           var responseHeaders = `X-Request-URL: http://somedomain.com
+           Foo: Bar`
+
+                                 connection.response.subscribe(res => {
+                                   expect(res.url).toEqual('http://somedomain.com');
+                                   async.done();
+                                 });
+
+           existingXHRs[0].setResponseHeaders(responseHeaders);
+           existingXHRs[0].setStatusCode(statusCode);
+           existingXHRs[0].dispatchEvent('load');
+         }));
     });
   });
 }