ios notif: Consume "background queue" so notifs navigate from backgro…

…und.

This is a short-term fix that relies on a deprecated API. We should
upgrade to a newer version of react-native-notifications or use
`@react-native-community/push-notification-ios` instead.

For docs on this as of the library version we're using (1.5.0 on NPM,
which has no Git tag but corresponds to commit 882775fb5), see:
  https://github.com/wix/react-native-notifications/blob/882775fb5/docs/notificationsEvents.md

The API was removed in release 2.0.6-shapshot-8 with commit:
  wix/react-native-notifications@800669120
presumably in response to:
  wix/react-native-notifications#339

Process an opened notification from the "background queue" so our
handleNotificationOpen will run, and the app will navigate, for a
notification opened while the app was in the background.

Fixes: zulip#3647

src/boot/AppEventHandlers.js

@@ -10,7 +10,11 @@ import type { Node as React$Node } from 'react';
 import type { Dispatch, Orientation as OrientationT } from '../types';
 import { connect } from '../react-redux';
 import { getUnreadByHuddlesMentionsAndPMs } from '../selectors';
-import { handleInitialNotification, NotificationListener } from '../notification';
+import {
+  handleInitialNotification,
+  NotificationListener,
+  notificationOnAppActive,
+} from '../notification';
 import { appOnline, appOrientation, appState, initSafeAreaInsets } from '../actions';
 import PresenceHeartbeat from '../presence/PresenceHeartbeat';
 
@@ -89,6 +93,9 @@ class AppEventHandlers extends PureComponent<Props> {
     if (state === 'background' && Platform.OS === 'android') {
       NativeModules.BadgeCountUpdaterModule.setBadgeCount(unreadCount);
     }
+    if (state === 'active') {
+      notificationOnAppActive();
+    }
   };
 
   notificationListener = new NotificationListener(this.props.dispatch);

src/notification/index.js

@@ -132,6 +132,29 @@ export const handleInitialNotification = async (dispatch: Dispatch) => {
   dispatch(narrowToNotification(data));
 };
 
+export const notificationOnAppActive = () => {
+  if (Platform.OS === 'ios') {
+    try {
+      // Allow 'notificationOpened' events to be emitted when pressing
+      // a notification when the app is in the background.
+      //
+      // TODO: This API is deprecated in react-native-notifications release
+      // 2.0.6-snapshot.8; see #3647.
+      //
+      // We don't know the behavior if this is called before
+      // NotificationsIOS.requestPermissions(), so, catch any errors
+      // silently. Ray's investigation shows that it *shouldn't*
+      // throw, but may (https://github.com/zulip/zulip-mobile/pull/3947#discussion_r389192513).
+      NotificationsIOS.consumeBackgroundQueue();
+    } catch (e) {
+      logging.warn(e, {
+        message:
+          'Call to NotificationsIOS.consumeBackgroundQueue failed; pressed notification failed to navigate',
+      });
+    }
+  }
+};
+
 /**
  * From rn-notifications@1.5.0's RNNotifications.m.
  */