Swift didReceiveRemoteNotification() Firebase not being called - swift

Question

After reading about this extensively, I cannot find the solution. I am sending cloud messages from Firebase to my ios app, but the method didReceiveRemoteNotification() is not being called at all, not when the app is in foreground and not in background. I tried sending from the firebase console, and also from postman using topics, and both don't work. I have integrated Firebase in the app, and uploaded certificate to Firebase, and I get no errors in the console. Just the notification isn't coming? I also added the capability of cloud messages.
This is what I do (from the Firebase tutorial) in appDelegate:
func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
// Override point for customization after application launch.
FirebaseApp.configure()
if #available(iOS 10.0, *) {
// For iOS 10 display notification (sent via APNS)
UNUserNotificationCenter.current().delegate = self
let authOptions: UNAuthorizationOptions = [.alert, .badge, .sound]
UNUserNotificationCenter.current().requestAuthorization(
options: authOptions,
completionHandler: {_, _ in })
} else {
let settings: UIUserNotificationSettings =
UIUserNotificationSettings(types: [.alert, .badge, .sound], categories: nil)
application.registerUserNotificationSettings(settings)
}
application.registerForRemoteNotifications()
Messaging.messaging().delegate = self
return true
}
func application(_ application: UIApplication, didReceiveRemoteNotification userInfo: [AnyHashable: Any]) {
// If you are receiving a notification message while your app is in the background,
// this callback will not be fired till the user taps on the notification launching the application.
// TODO: Handle data of notification
// With swizzling disabled you must let Messaging know about the message, for Analytics
// Messaging.messaging().appDidReceiveMessage(userInfo)
// Print message ID.
if let messageID = userInfo[gcmMessageIDKey] {
print("Message ID: \(messageID)")
}
// Print full message.
print(userInfo)
}
func application(_ application: UIApplication, didReceiveRemoteNotification userInfo: [AnyHashable: Any],
fetchCompletionHandler completionHandler: #escaping (UIBackgroundFetchResult) -> Void) {
// If you are receiving a notification message while your app is in the background,
// this callback will not be fired till the user taps on the notification launching the application.
// TODO: Handle data of notification
// With swizzling disabled you must let Messaging know about the message, for Analytics
// Messaging.messaging().appDidReceiveMessage(userInfo)
// Print message ID.
if let messageID = userInfo[gcmMessageIDKey] {
print("Message ID: \(messageID)")
}
// Print full message.
print(userInfo)
completionHandler(UIBackgroundFetchResult.newData)
}

Answer 1

Disable Method swizzling and everything should work fine.
According to the documentation https://firebase.google.com/docs/cloud-messaging/ios/client#token-swizzle-disabled
If you have disabled method swizzling, or you are building a SwiftUI app, you'll need to explicitly map your APNs token to the FCM registration token. Implement the application(_:didRegisterForRemoteNotificationsWithDeviceToken:) method to retrieve the APNs token, and then set Messaging's apnsToken property
It also mentions here https://firebase.google.com/docs/cloud-messaging/ios/receive#handle_messages_with_method_swizzling_disabled
By default, if you assign your app's app delegate class to the UNUserNotificationCenter and Messaging delegate properties, FCM will swizzle your app delegate class to automatically associate your FCM token with the device's APNs token and pass notification-received events to Analytics. If you explicitly disable method swizzling, if you are building a SwiftUI app, or if you use a separate class for either delegate, you will need to perform both of these tasks manually.
Mapping apnToken and deviceToken is to be done at various places thus it's advised to read the documentation completely and apply the necessary changes.