fix(messaging): Throw exception if APNS token is not yet available (#11400)

Co-authored-by: Kevin Cheung <[email protected]>

Author: 2 people

docs/cloud-messaging/client.md

@@ -144,8 +144,20 @@ To retrieve the current registration token for an app instance, call
 ask the user for notification permissions. Otherwise, it returns a token or
 rejects the future due to an error.
 
+Warning: In iOS SDK 10.4.0 and higher, it is a requirement that the APNs token
+is available before making API requests. The APNs token is not guaranteed to have been received
+before making FCM plugin API requests.
+
 ```dart
-final fcmToken = await FirebaseMessaging.instance.getToken();
+// You may set the permission requests to "provisional" which allows the user to choose what type
+// of notifications they would like to receive once the user receives a notification.
+final notificationSettings = await FirebaseMessaging.instance.requestPermission(provisional: true);
+
+// For apple platforms, ensure the APNS token is available before making any FCM plugin API calls
+final apnsToken = await FirebaseMessaging.instance.getAPNSToken();
+if (apnsToken != null) {
+ // APNS token is available, make FCM plugin API requests...
+}
 ```
 
 On web platforms, pass your VAPID public key to `getToken()`:

packages/firebase_messaging/firebase_messaging_platform_interface/lib/src/method_channel/method_channel_messaging.dart

@@ -4,6 +4,7 @@
 // BSD-style license that can be found in the LICENSE file.
 
 import 'dart:async';
+import 'dart:io' show Platform;
 import 'dart:ui';
 
 import 'package:firebase_core/firebase_core.dart';
@@ -126,6 +127,24 @@ class MethodChannelFirebaseMessaging extends FirebaseMessagingPlatform {
   static StreamController<String> tokenStreamController =
       StreamController<String>.broadcast();
 
+  // Created this to check APNS token is available before certain Apple Firebase
+  // Messaging requests. See this issue:
+  // https://github.com/firebase/flutterfire/issues/10625
+  Future<void> _APNSTokenCheck() async {
+    if (Platform.isMacOS || Platform.isIOS) {
+      String? token = await getAPNSToken();
+
+      if (token == null) {
+        throw FirebaseException(
+          plugin: 'firebase_messaging',
+          code: 'apns-token-not-set',
+          message:
+              'APNS token has not been set yet. Please ensure the APNS token is available by calling `getAPNSToken()`.',
+        );
+      }
+    }
+  }
+
   @override
   FirebaseMessagingPlatform delegateFor({required FirebaseApp app}) {
     return MethodChannelFirebaseMessaging(app: app);
@@ -189,6 +208,8 @@ class MethodChannelFirebaseMessaging extends FirebaseMessagingPlatform {
 
   @override
   Future<void> deleteToken() async {
+    await _APNSTokenCheck();
+
     try {
       await channel
           .invokeMapMethod('Messaging#deleteToken', {'appName': app.name});
@@ -220,6 +241,8 @@ class MethodChannelFirebaseMessaging extends FirebaseMessagingPlatform {
   Future<String?> getToken({
     String? vapidKey, // not used yet; web only property
   }) async {
+    await _APNSTokenCheck();
+
     try {
       Map<String, String?>? data =
           await channel.invokeMapMethod<String, String>('Messaging#getToken', {
@@ -364,6 +387,8 @@ class MethodChannelFirebaseMessaging extends FirebaseMessagingPlatform {
 
   @override
   Future<void> subscribeToTopic(String topic) async {
+    await _APNSTokenCheck();
+
     try {
       await channel.invokeMapMethod('Messaging#subscribeToTopic', {
         'appName': app.name,
@@ -376,6 +401,8 @@ class MethodChannelFirebaseMessaging extends FirebaseMessagingPlatform {
 
   @override
   Future<void> unsubscribeFromTopic(String topic) async {
+    await _APNSTokenCheck();
+
     try {
       await channel.invokeMapMethod('Messaging#unsubscribeFromTopic', {
         'appName': app.name,