fix(http): return Response headers

Properly parse and add response Headers to Response.

Closes #5237

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

@@ -2,6 +2,7 @@ import {ConnectionBackend, Connection} from '../interfaces';
 import {ReadyStates, RequestMethods, ResponseTypes} from '../enums';
 import {Request} from '../static_request';
 import {Response} from '../static_response';
+import {Headers} from '../headers';
 import {ResponseOptions, BaseResponseOptions} from '../base_response_options';
 import {Injectable} from 'angular2/angular2';
 import {BrowserXhr} from './browser_xhr';
@@ -34,8 +35,9 @@ export class XHRConnection implements Connection {
         // responseText is the old-school way of retrieving response (supported by IE8 & 9)
         // response/responseType properties were introduced in XHR Level2 spec (supported by
         // IE10)
-        let xhrResponse = isPresent(_xhr.response) ? _xhr.response : _xhr.responseText;
+        let body = isPresent(_xhr.response) ? _xhr.response : _xhr.responseText;
 
+        let headers = Headers.fromResponseHeaderString(_xhr.getAllResponseHeaders());
 
         // normalize IE9 bug (http://bugs.jquery.com/ticket/1450)
         let status: number = _xhr.status === 1223 ? 204 : _xhr.status;
@@ -44,9 +46,9 @@ export class XHRConnection implements Connection {
         // Occurs when accessing file resources or on Android 4.1 stock browser
         // while retrieving files from application cache.
         if (status === 0) {
-          status = xhrResponse ? 200 : 0;
+          status = body ? 200 : 0;
         }
-        var responseOptions = new ResponseOptions({body: xhrResponse, status: status});
+        var responseOptions = new ResponseOptions({body, status, headers});
         if (isPresent(baseResponseOptions)) {
           responseOptions = baseResponseOptions.merge(responseOptions);
         }

modules/angular2/src/http/headers.ts

@@ -54,6 +54,17 @@ export class Headers {
         headers, (v, k) => { this._headersMap.set(k, isListLikeIterable(v) ? v : [v]); });
   }
 
+  /**
+   * Returns a new Headers instance from the given DOMString of Response Headers
+   */
+  static fromResponseHeaderString(headersString: string): Headers {
+    return headersString.trim()
+        .split('\n')
+        .map(val => val.split(':'))
+        .map(([key, ...parts]) => ([key.trim(), parts.join(':').trim()]))
+        .reduce((headers, [key, value]) => !headers.set(key, value) && headers, new Headers());
+  }
+
   /**
    * Appends a header to existing list of header values for a given header name.
    */

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

@@ -40,6 +40,7 @@ class MockBrowserXHR extends BrowserXhr {
   setRequestHeader: any;
   callbacks = new Map<string, Function>();
   status: number;
+  responseHeaders: string;
   constructor() {
     super();
     var spy = new SpyObject();
@@ -55,6 +56,10 @@ class MockBrowserXHR extends BrowserXhr {
 
   setResponseText(value) { this.responseText = value; }
 
+  setResponseHeaders(value) { this.responseHeaders = value; }
+
+  getAllResponseHeaders() { return this.responseHeaders || ''; }
+
   addEventListener(type: string, cb: Function) { this.callbacks.set(type, cb); }
 
   removeEventListener(type: string, cb: Function) { this.callbacks.delete(type); }
@@ -256,6 +261,30 @@ export function main() {
            existingXHRs[0].dispatchEvent('load');
          }));
 
+      it('should parse response headers and add them to the response',
+         inject([AsyncTestCompleter], async => {
+           var statusCode = 200;
+           var connection = new XHRConnection(sampleRequest, new MockBrowserXHR(),
+                                              new ResponseOptions({status: statusCode}));
+
+           let responseHeaderString =
+               `Date: Fri, 20 Nov 2015 01:45:26 GMT
+               Content-Type: application/json; charset=utf-8
+               Transfer-Encoding: chunked
+               Connection: keep-alive`
+
+               connection.response.subscribe(res => {
+                 expect(res.headers.get('Date')).toEqual('Fri, 20 Nov 2015 01:45:26 GMT');
+                 expect(res.headers.get('Content-Type')).toEqual('application/json; charset=utf-8');
+                 expect(res.headers.get('Transfer-Encoding')).toEqual('chunked');
+                 expect(res.headers.get('Connection')).toEqual('keep-alive');
+                 async.done();
+               });
+
+           existingXHRs[0].setResponseHeaders(responseHeaderString);
+           existingXHRs[0].setStatusCode(statusCode);
+           existingXHRs[0].dispatchEvent('load');
+         }));
     });
   });
 }

modules/angular2/test/http/headers_spec.ts

@@ -63,4 +63,23 @@ export function main() {
       });
     });
   });
+
+  describe('.fromResponseHeaderString()', () => {
+
+    it('should parse a response header string', () => {
+
+      let responseHeaderString = `Date: Fri, 20 Nov 2015 01:45:26 GMT
+        Content-Type: application/json; charset=utf-8
+        Transfer-Encoding: chunked
+        Connection: keep-alive`;
+
+      let responseHeaders = Headers.fromResponseHeaderString(responseHeaderString);
+
+      expect(responseHeaders.get('Date')).toEqual('Fri, 20 Nov 2015 01:45:26 GMT');
+      expect(responseHeaders.get('Content-Type')).toEqual('application/json; charset=utf-8');
+      expect(responseHeaders.get('Transfer-Encoding')).toEqual('chunked');
+      expect(responseHeaders.get('Connection')).toEqual('keep-alive');
+
+    });
+  });
 }