[FCM] Add completion handler to subscribe/unsubscribe topic actions

Added functionality not exposed in public header yet. I would leave to next FCM SDK owner to expose this functionality (and follow any required review process).

Bugs:
72701086

4 files changed, 31 insertions, 9 deletions

diff --git a/Firebase/Messaging/FIRMessaging.m b/Firebase/Messaging/FIRMessaging.m
index 11cacb3..d0edadf 100644
--- a/Firebase/Messaging/FIRMessaging.m
+++ b/Firebase/Messaging/FIRMessaging.m
@@ -683,10 +683,15 @@ static NSString *const kFIRMessagingPlistAutoInitEnabled =
 }
 
 - (void)subscribeToTopic:(NSString *)topic {
+  [self subscribeToTopic:topic completion:nil];
+}
+
+- (void)subscribeToTopic:(NSString *)topic
+              completion:(nullable FIRMessagingTopicOperationCompletion)completion {
   if (self.defaultFcmToken.length && topic.length) {
     NSString *normalizeTopic = [[self class ] normalizeTopic:topic];
     if (normalizeTopic.length) {
-      [self.pubsub subscribeToTopic:normalizeTopic];
+      [self.pubsub subscribeToTopic:normalizeTopic handler:completion];
     } else {
       FIRMessagingLoggerError(kFIRMessagingMessageCodeMessaging009,
                               @"Cannot parse topic name %@. Will not subscribe.", topic);
@@ -699,10 +704,15 @@ static NSString *const kFIRMessagingPlistAutoInitEnabled =
 }
 
 - (void)unsubscribeFromTopic:(NSString *)topic {
+  [self unsubscribeFromTopic:topic completion:nil];
+}
+
+- (void)unsubscribeFromTopic:(NSString *)topic
+                  completion:(nullable FIRMessagingTopicOperationCompletion)completion {
   if (self.defaultFcmToken.length && topic.length) {
     NSString *normalizeTopic = [[self class] normalizeTopic:topic];
     if (normalizeTopic.length) {
-      [self.pubsub unsubscribeFromTopic:normalizeTopic];
+      [self.pubsub unsubscribeFromTopic:normalizeTopic handler:completion];
     } else {
       FIRMessagingLoggerError(kFIRMessagingMessageCodeMessaging011,
                               @"Cannot parse topic name %@. Will not unsubscribe.", topic);
diff --git a/Firebase/Messaging/FIRMessagingPubSub.h b/Firebase/Messaging/FIRMessagingPubSub.h
index 3a03494..2ce8ed4 100644
--- a/Firebase/Messaging/FIRMessagingPubSub.h
+++ b/Firebase/Messaging/FIRMessagingPubSub.h
@@ -59,6 +59,7 @@
  *                   library for a given `authorizedEntity` and "gcm" scope.
  *  @param topic    The topic to subscribe to. Should be of the form
  *                  `"/topics/<topic-name>"`.
+ *  @param options  Unused parameter, please pass nil or empty dictionary.
  *  @param handler  The callback handler invoked when the subscribe call
  *                  ends. In case of success, a nil error is returned. Otherwise,
  *                  an appropriate error object is returned.
@@ -70,7 +71,6 @@
                    options:(NSDictionary *)options
                    handler:(FIRMessagingTopicOperationCompletion)handler;
 
-
 /**
  *  Unsubscribes an app instance from a topic, stopping it from receiving
  *  any further messages sent to that topic.
@@ -81,6 +81,7 @@
  *  @param token   The token used to subscribe to this topic.
  *  @param topic   The topic to unsubscribe from. Should be of the form
  *                 `"/topics/<topic-name>"`.
+ *  @param options Unused parameter, please pass nil or empty dictionary.
  *  @param handler The handler that is invoked once the unsubscribe call ends.
  *                 In case of success, nil error is returned. Otherwise, an
  *                  appropriate error object is returned.
@@ -98,8 +99,12 @@
  *  as compared to the `subscribe` method above which tries once.
  *
  *  @param topic The topic name to subscribe to. Should be of the form `"/topics/<topic-name>"`.
+ *  @param handler The handler that is invoked once the unsubscribe call ends.
+ *                 In case of success, nil error is returned. Otherwise, an
+ *                  appropriate error object is returned.
  */
-- (void)subscribeToTopic:(NSString *)topic;
+- (void)subscribeToTopic:(NSString *)topic
+                 handler:(nullable FIRMessagingTopicOperationCompletion)handler;
 
 /**
  *  Asynchronously unsubscribe from the topic. Adds to the pending list of topic operations.
@@ -107,8 +112,12 @@
  *  as compared to the `unsubscribe` method above which tries once.
  *
  *  @param topic The topic name to unsubscribe from. Should be of the form `"/topics/<topic-name>"`.
+ *  @param handler The handler that is invoked once the unsubscribe call ends.
+ *                 In case of success, nil error is returned. Otherwise, an
+ *                  appropriate error object is returned.
  */
-- (void)unsubscribeFromTopic:(NSString *)topic;
+- (void)unsubscribeFromTopic:(NSString *)topic
+                     handler:(nullable FIRMessagingTopicOperationCompletion)handler;
 
 /**
  *  Schedule subscriptions sync.
diff --git a/Firebase/Messaging/FIRMessagingPubSub.m b/Firebase/Messaging/FIRMessagingPubSub.m
index c8293e0..74a5292 100644
--- a/Firebase/Messaging/FIRMessagingPubSub.m
+++ b/Firebase/Messaging/FIRMessagingPubSub.m
@@ -146,16 +146,18 @@ static NSString *const kPendingSubscriptionsListKey =
   }];
 }
 
-- (void)subscribeToTopic:(NSString *)topic {
+- (void)subscribeToTopic:(NSString *)topic
+                 handler:(nullable FIRMessagingTopicOperationCompletion)handler {
   [self.pendingTopicUpdates addOperationForTopic:topic
                                       withAction:FIRMessagingTopicActionSubscribe
-                                      completion:nil];
+                                      completion:handler];
 }
 
-- (void)unsubscribeFromTopic:(NSString *)topic {
+- (void)unsubscribeFromTopic:(NSString *)topic
+                     handler:(nullable FIRMessagingTopicOperationCompletion)handler {
   [self.pendingTopicUpdates addOperationForTopic:topic
                                       withAction:FIRMessagingTopicActionUnsubscribe
-                                      completion:nil];
+                                      completion:handler];
 }
 
 - (void)scheduleSync:(BOOL)immediately {
diff --git a/Firebase/Messaging/FIRMessagingTopicOperation.m b/Firebase/Messaging/FIRMessagingTopicOperation.m
index 90760eb..3120240 100644
--- a/Firebase/Messaging/FIRMessagingTopicOperation.m
+++ b/Firebase/Messaging/FIRMessagingTopicOperation.m
@@ -82,6 +82,7 @@ NSString *FIRMessagingSubscriptionsServer() {
     _topic = topic;
     _action = action;
     _token = token;
+    _options = options;
     _checkinService = checkinService;
     _completion = completion;