Late setNotificationOpenedHandler call processing

iOS_SDK/OneSignalSDK/Source/OneSignalHelper.m

@@ -214,13 +214,17 @@ @implementation OneSignalHelper
 NSDictionary* lastMessageReceived;
 UIBackgroundTaskIdentifier mediaBackgroundTask;
 
+static NSMutableArray<OSNotificationOpenedResult*> *unprocessedOpenedNotifis;
+
 + (void)resetLocals {
     [OneSignalHelper lastMessageReceived:nil];
     _lastMessageIdFromAction = nil;
     lastMessageID = @"";
 
     notificationWillShowInForegroundHandler = nil;
     notificationOpenedHandler = nil;
+
+    unprocessedOpenedNotifis = nil;
 }
 
 OSNotificationWillShowInForegroundBlock notificationWillShowInForegroundHandler;
@@ -231,6 +235,27 @@ + (void)setNotificationWillShowInForegroundBlock:(OSNotificationWillShowInForegr
 OSNotificationOpenedBlock notificationOpenedHandler;
 + (void)setNotificationOpenedBlock:(OSNotificationOpenedBlock)block {
     notificationOpenedHandler = block;
+    [self fireNotificationOpenedHandlerForUnprocessedEvents];
+}
+
++ (NSMutableArray<OSNotificationOpenedResult*>*)getUnprocessedOpenedNotifis {
+    if (!unprocessedOpenedNotifis)
+        unprocessedOpenedNotifis = [NSMutableArray new];
+    return unprocessedOpenedNotifis;
+}
+
++ (void)addUnprocessedOpenedNotifi:(OSNotificationOpenedResult*)result {
+    [[self getUnprocessedOpenedNotifis] addObject:result];
+}
+
++ (void)fireNotificationOpenedHandlerForUnprocessedEvents {
+    if (!notificationOpenedHandler)
+        return;
+
+    for (OSNotificationOpenedResult* notification in [self getUnprocessedOpenedNotifis]) {
+        notificationOpenedHandler(notification);
+    }
+    unprocessedOpenedNotifis = [NSMutableArray new];
 }
 
 //Passed to the OnFocus to make sure dismissed when coming back into app
@@ -358,8 +383,10 @@ + (void)handleNotificationAction:(OSNotificationActionType)actionType actionID:(
 
     [OneSignalTrackFirebaseAnalytics trackOpenEvent:result];
 
-    if (!notificationOpenedHandler)
+    if (!notificationOpenedHandler) {
+        [self addUnprocessedOpenedNotifi:result];
         return;
+    }
     notificationOpenedHandler(result);
 }
 

iOS_SDK/OneSignalSDK/UnitTests/UnitTests.m

@@ -790,6 +790,33 @@ - (void)testNotificationOpen {
     XCTAssertEqual(OneSignalClientOverrider.networkRequestCount, 3);
 }
 
+/**
+ Ensures that if a developer calls OneSignal.setNotificationOpenedHandler late (after didFinishLaunchingWithOptionst)
+and the app was cold started from opening a notficiation open that the developer's handler will still fire.
+ This is particularly helpful for the OneSignal wrapper SDKs so special logic isn't needed in each one.
+ */
+- (void)testNotificationOpenedHandler_setAfter_didFinishLaunchingWithOptions {
+    // 1. Init OneSignal with app start
+    [UnitTestCommonMethods initOneSignal];
+    [UnitTestCommonMethods runBackgroundThreads];
+
+    // 2. Simulate a notification being opened
+    let notifResponse = [self createBasiciOSNotificationResponse];
+    let notifCenter = UNUserNotificationCenter.currentNotificationCenter;
+    let notifCenterDelegate = notifCenter.delegate;
+    [notifCenterDelegate userNotificationCenter:notifCenter didReceiveNotificationResponse:notifResponse withCompletionHandler:^() {}];
+
+    // 3. Setup OneSignal.setNotificationOpenedHandler
+    __block BOOL openedWasFire = false;
+    [OneSignal setNotificationOpenedHandler:^(OSNotificationOpenedResult * _Nonnull result) {
+        openedWasFire = true;
+    }];
+    // 4. Wait for open event to fire
+    [UnitTestCommonMethods runBackgroundThreads];
+
+    // 5. Ensure the OneSignal public callback fired
+    XCTAssertTrue(openedWasFire);
+}
 
 - (UNNotificationResponse*)createNotificationResponseForAnalyticsTests {
     id userInfo = @{@"custom":