Auto complete early when no user listeners.

This is to clear up memory on the objective-c side without needing to
signal the start/stop of user listeners.

ios/RNFirebase/notifications/RNFirebaseNotifications.m

@@ -17,7 +17,6 @@
 @end
 
 @implementation RNFirebaseNotifications {
-    BOOL isUserHandlingOnNotificationDisplayed;
     NSMutableDictionary<NSString *, void (^)(UIBackgroundFetchResult)> *completionHandlers;
 }
 
@@ -57,6 +56,7 @@ RCT_EXPORT_MODULE();
 
     // Set static instance for use from AppDelegate
     theRNFirebaseNotifications = self;
+    completionHandlers = [[NSMutableDictionary alloc] init];
 }
 
 // PRE-BRIDGE-EVENTS: Consider enabling this to allow events built up before the bridge is built to be sent to the JS side
@@ -98,31 +98,6 @@ RCT_EXPORT_MODULE();
     }
 }
 
-RCT_EXPORT_METHOD(startHandlingNotificationDisplayed) {
-    if(isUserHandlingOnNotificationDisplayed == YES) {
-        return;
-    }
-    
-    isUserHandlingOnNotificationDisplayed = YES;
-    
-    completionHandlers = [[NSMutableDictionary alloc] init];
-}
-
-RCT_EXPORT_METHOD(stopHandlingNotificationDisplayed) {
-    if(isUserHandlingOnNotificationDisplayed == NO) {
-        return;
-    }
-    
-    isUserHandlingOnNotificationDisplayed = NO;
-    
-    NSArray *allHandlers = completionHandlers.allValues;
-    for (void (^ completionHandler)(UIBackgroundFetchResult) in allHandlers) {
-        completionHandler(UIBackgroundFetchResultNoData);
-    }
-    [completionHandlers removeAllObjects];
-    completionHandlers = nil;
-}
-
 RCT_EXPORT_METHOD(complete:(NSString*)handlerKey fetchResult:(UIBackgroundFetchResult)fetchResult) {
     void (^completionHandler)(UIBackgroundFetchResult) = completionHandlers[handlerKey];
     completionHandlers[handlerKey] = nil;
@@ -132,15 +107,6 @@ RCT_EXPORT_METHOD(complete:(NSString*)handlerKey fetchResult:(UIBackgroundFetchR
     }
 }
 
-- (void)executeOrStoreCompletionHandler:(void (^ _Nonnull)(UIBackgroundFetchResult))completionHandler notification:(NSDictionary *)notification {
-    if(isUserHandlingOnNotificationDisplayed) {
-        NSString *handlerKey = notification[@"notificationId"];
-        completionHandlers[handlerKey] = completionHandler;
-    } else {
-        completionHandler(UIBackgroundFetchResultNoData);
-    }
-}
-
 // Listen for background messages
 - (void)didReceiveRemoteNotification:(NSDictionary *)userInfo
               fetchCompletionHandler:(void (^)(UIBackgroundFetchResult))completionHandler {
@@ -153,6 +119,7 @@ RCT_EXPORT_METHOD(complete:(NSString*)handlerKey fetchResult:(UIBackgroundFetchR
     }
 
     NSDictionary *notification = [self parseUserInfo:userInfo];
+    NSString *handlerKey = notification[@"notificationId"];
 
     NSString *event;
     if (RCTSharedApplication().applicationState == UIApplicationStateBackground) {
@@ -180,7 +147,7 @@ RCT_EXPORT_METHOD(complete:(NSString*)handlerKey fetchResult:(UIBackgroundFetchR
                          };
     }
 
-    [self executeOrStoreCompletionHandler:completionHandler notification:notification];
+    completionHandlers[handlerKey] = completionHandler;
     
     [self sendJSEvent:self name:event body:notification];
 }

lib/modules/notifications/index.js

@@ -128,11 +128,14 @@ export default class Notifications extends ModuleBase {
           android: () => {},
         });
 
-        SharedEventEmitter.emit(
+        const publicEventName = 'onNotificationDisplayed';
-          'onNotificationDisplayed',
+
-          rnNotification,
+        if (!hasListeners(publicEventName)) {
-          done
+          // if user is not handling completion then we need to
-        );
+          done(this.backgroundFetchResult.noData);
+        }
+
+        SharedEventEmitter.emit(publicEventName, rnNotification, done);
       }
     );
 
@@ -271,10 +274,12 @@ export default class Notifications extends ModuleBase {
     nextOrObserver: OnNotification | OnNotificationObserver
   ): () => any {
     const isNext = isFunction(nextOrObserver);
-    const isObserver = isObject(nextOrObserver) && isFunction(nextOrObserver.next);
+    const isObserver =
+      isObject(nextOrObserver) && isFunction(nextOrObserver.next);
+    const eventName = 'onNotificationDisplayed';
     if (!isNext && !isObserver) {
       throw new Error(
-        'Notifications.onNotificationDisplayed failed: First argument must be a function or observer object with a `next` function.'
+        `Notifications.${eventName} failed: First argument must be a function or observer object with a \`next\` function.`
       );
     }
 
@@ -285,24 +290,21 @@ export default class Notifications extends ModuleBase {
       listener = nextOrObserver;
     }
 
-    const autoCompletingListener: OnNotification = async (notification, done) => {
+    const autoCompletingListener: OnNotification = async (
+      notification,
+      done
+    ) => {
       const listenerResult = await listener(notification, done);
       done(this.backgroundFetchResult.noData);
       return listenerResult;
     };
 
-    getLogger(this).info('Creating onNotificationDisplayed listener');
+    getLogger(this).info(`Creating ${eventName} listener`);
-    SharedEventEmitter.addListener('onNotificationDisplayed', autoCompletingListener);
+    SharedEventEmitter.addListener(eventName, autoCompletingListener);
-    if (hasListeners('onNotificationDisplayed')) {
-      getNativeModule(this).startHandlingNotificationDisplayed();
-    }
 
     return () => {
-      getLogger(this).info('Removing onNotificationDisplayed listener');
+      getLogger(this).info(`Removing ${eventName} listener`);
-      SharedEventEmitter.removeListener('onNotificationDisplayed', autoCompletingListener);
+      SharedEventEmitter.removeListener(eventName, autoCompletingListener);
-      if (!hasListeners('onNotificationDisplayed')) {
-        getNativeModule(this).stopHandlingNotificationDisplayed();
-      }
     };
   }