Support redirects in NewtorkManager

This patch adds support to redirects so that they will be reported
as a separate requests.

References #26.

lib/NetworkManager.js

@@ -92,6 +92,13 @@ class NetworkManager extends EventEmitter {
    * @param {!Object} event
    */
   _onRequestWillBeSent(event) {
+    if (event.redirectResponse) {
+      let request = this._idToRequest.get(event.requestId);
+      let response = new Response(request, event.redirectResponse);
+      request._response = response;
+      this.emit(NetworkManager.Events.Response, response);
+      this.emit(NetworkManager.Events.RequestFinished, request);
+    }
     let request = new Request(event.request);
     this._idToRequest.set(event.requestId, request);
     this.emit(NetworkManager.Events.Request, request);

test/StaticServer.js

@@ -54,6 +54,17 @@ class StaticServer {
     this._routes.set(path, handler);
   }
 
+  /**
+   * @param {string} fromPath
+   * @param {string} toPath
+   */
+  setRedirect(from, to) {
+    this.setRoute(from, (req, res) => {
+      res.writeHead(302, { location: to });
+      res.end();
+    });
+  }
+
   /**
    * @param {string} path
    * @return {!Promise<!IncomingMessage>}

test/test.js

@@ -547,6 +547,24 @@ describe('Puppeteer', function() {
       await page.navigate(EMPTY_PAGE);
       expect(events).toEqual(['request', 'response', 'requestfinished']);
     }));
+    it('should support redirects', SX(async function() {
+      let events = [];
+      page.on('request', request => events.push(`${request.method} ${request.url}`));
+      page.on('response', response => events.push(`${response.status} ${response.url}`));
+      page.on('requestfinished', request => events.push(`DONE ${request.url}`));
+      page.on('requestfailed', request => events.push(`FAIL ${request.url}`));
+      staticServer.setRedirect('/foo.html', '/empty.html');
+      const FOO_URL = STATIC_PREFIX + '/foo.html';
+      await page.navigate(FOO_URL);
+      expect(events).toEqual([
+        `GET ${FOO_URL}`,
+        `302 ${FOO_URL}`,
+        `DONE ${FOO_URL}`,
+        `GET ${EMPTY_PAGE}`,
+        `200 ${EMPTY_PAGE}`,
+        `DONE ${EMPTY_PAGE}`
+      ]);
+    }));
   });
 });