Handling errors from chrome APIs

chrome/browser/resources/google_now/background.js

 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 'use strict';
 
 /**
  * @fileoverview The event page for Google Now for Chrome implementation.
  * The Google Now event page gets Google Now cards from the server and shows
  * them as Chrome notifications.
  * The service performs periodic updating of Google Now cards.
  * Each updating of the cards includes 4 steps:
  * 1. Obtaining the location of the machine;
  * 2. Processing requests for cards dismissals that are not yet sent to the
  *    server;
  * 3. Making a server request based on that location;
  * 4. Showing the received cards as notifications.
  */
 
 // TODO(vadimt): Use background permission to show notifications even when all
 // browser windows are closed.
 // TODO(vadimt): Decide what to do in incognito mode.
 // TODO(vadimt): Honor the flag the enables Google Now integration.
 // TODO(vadimt): Figure out the final values of the constants.
 // TODO(vadimt): Remove 'console' calls.
-// TODO(vadimt): Consider sending JS stacks for chrome.* API errors and
-// malformed server responses.
+// TODO(vadimt): Consider sending JS stacks for malformed server responses.
 
 /**
  * Standard response code for successful HTTP requests. This is the only success
  * code the server will send.
  */
 var HTTP_OK = 200;
 
 var HTTP_BAD_REQUEST = 400;
 var HTTP_UNAUTHORIZED = 401;
 var HTTP_FORBIDDEN = 403;
@@ skipping 301 matching lines @@
  * For example, this occurs when the geolocation preference is unchecked in the
  * content settings.
  */
 function removeAllCards() {
   console.log('removeAllCards');
 
   // TODO(robliao): Once Google Now clears its own checkbox in the
   // notifications center and bug 260376 is fixed, the below clearing
   // code is no longer necessary.
   instrumented.notifications.getAll(function(notifications) {
+    notifications = notifications || {};
     for (var notificationId in notifications) {
       chrome.notifications.clear(notificationId, function() {});
     }
     chrome.storage.local.set({notificationsData: {}});
   });
 }
 
 /**
  * Requests notification cards from the server.
  * @param {Location} position Location of this computer.
@@ skipping 39 matching lines @@
   });
 }
 
 /**
  * Starts getting location for a cards update.
  */
 function requestLocation() {
   console.log('requestLocation');
   recordEvent(GoogleNowEvent.LOCATION_REQUEST);
   // TODO(vadimt): Figure out location request options.
-  chrome.metricsPrivate.getVariationParams('GoogleNow', function(params) {
+  instrumented.metricsPrivate.getVariationParams('GoogleNow', function(params) {
     var minDistanceInMeters =
         parseInt(params && params.minDistanceInMeters, 10) ||
         100;
     var minTimeInMilliseconds =
         parseInt(params && params.minTimeInMilliseconds, 10) ||
         180000;  // 3 minutes.
 
     chrome.location.watchLocation(LOCATION_WATCH_NAME, {
       minDistanceInMeters: minDistanceInMeters,
       minTimeInMilliseconds: minTimeInMilliseconds
@@ skipping 156 matching lines @@
 }
 
 /**
  * Opens URL corresponding to the clicked part of the notification.
  * @param {string} notificationId Unique identifier of the notification.
  * @param {function(Object): string} selector Function that extracts the url for
  *     the clicked area from the button action URLs info.
  */
 function onNotificationClicked(notificationId, selector) {
   instrumented.storage.local.get('notificationsData', function(items) {
-    items.notificationsData = items.notificationsData || {};
+    var notificationData = items &&
+        items.notificationsData &&
+        items.notificationsData[notificationId];
 
-    var notificationData = items.notificationsData[notificationId];
-
-    if (!notificationData) {
-      // 'notificationsData' in storage may not match the actual list of
-      // notifications.
+    if (!notificationData)
       return;
-    }
 
     var actionUrls = notificationData.actionUrls;
     if (typeof actionUrls != 'object') {
       return;
     }
 
     var url = selector(actionUrls);
-
-    if (typeof url != 'string')
+    if (!url)
       return;
 
     instrumented.tabs.create({url: url}, function(tab) {
       if (tab)
         chrome.windows.update(tab.windowId, {focused: true});
       else
         chrome.windows.create({url: url, focused: true});
     });
   });
 }
@@ skipping 266 matching lines @@
             instrumented.
                 preferencesPrivate.
                 googleGeolocationAccessEnabled.
                 get({}, function(prefValue) {
                   var geolocationEnabled = !!prefValue.value;
                   tasks.debugSetStepName(
                     'onStateChange-get-userRespondedToToast');
                   instrumented.storage.local.get(
                       'userRespondedToToast',
                       function(items) {
-                        var userRespondedToToast = !!items.userRespondedToToast;
+                        var userRespondedToToast =
+                            !items || !!items.userRespondedToToast;
                         updateRunningState(
                             signedIn,
                             geolocationEnabled,
                             userRespondedToToast,
                             enableBackground,
                             callback);
                       });
                 });
           });
     });
@@ skipping 67 matching lines @@
     });
 
 instrumented.notifications.onButtonClicked.addListener(
     function(notificationId, buttonIndex) {
       if (notificationId == WELCOME_TOAST_NOTIFICATION_ID) {
         onToastNotificationClicked(buttonIndex);
       } else {
         chrome.metricsPrivate.recordUserAction(
             'GoogleNow.ButtonClicked' + buttonIndex);
         onNotificationClicked(notificationId, function(actionUrls) {
-          if (!Array.isArray(actionUrls.buttonUrls))
-            return undefined;
-
-          return actionUrls.buttonUrls[buttonIndex];
+          var url = actionUrls.buttonUrls[buttonIndex];
+          verify(url, 'onButtonClicked: no url for a button');
+          return url;
         });
       }
     });
 
 instrumented.notifications.onClosed.addListener(onNotificationClosed);
 
 instrumented.location.onLocationUpdate.addListener(function(position) {
   recordEvent(GoogleNowEvent.LOCATION_UPDATE);
   updateNotificationsCards(position);
 });
 
 instrumented.omnibox.onInputEntered.addListener(function(text) {
   localStorage['server_url'] = NOTIFICATION_CARDS_URL = text;
   initialize();
 });