Added overload to unsubscribe from a collection immediately

Author: Ben305

Meteor/METDDPClient.h

@@ -95,6 +95,7 @@ typedef void (^METLogOutCompletionHandler)(NSError * __nullable error);
 - (METSubscription *)addSubscriptionWithName:(NSString *)name parameters:(nullable NSArray *)parameters;
 - (METSubscription *)addSubscriptionWithName:(NSString *)name parameters:(nullable NSArray *)parameters completionHandler:(nullable METSubscriptionCompletionHandler)completionHandler;
 - (void)removeSubscription:(METSubscription *)subscription;
+- (void)removeSubscription:(METSubscription *)subscription immediately:(BOOL)immediately completionHandler:(nullable METSubscriptionCompletionHandler)completionHandler;
 
 #pragma mark - Method Invocations
 /// @name Defining Method Stubs

Meteor/METDDPClient.m

@@ -520,7 +520,11 @@ - (void)sendSubMessageForSubscription:(METSubscription *)subscription {
 }
 
 - (void)removeSubscription:(METSubscription *)subscription {
-  [_subscriptionManager removeSubscription:subscription];
+    [self removeSubscription:subscription immediately:NO completionHandler:nil];
+}
+
+- (void)removeSubscription:(METSubscription *)subscription immediately:(BOOL)immediately completionHandler:(nullable METSubscriptionCompletionHandler)completionHandler {
+  [_subscriptionManager removeSubscription:subscription immediately:immediately completionHandler:completionHandler];
 }
 
 - (void)sendUnsubMessageForSubscription:(METSubscription *)subscription {

Meteor/METSubscriptionManager.h

@@ -35,7 +35,7 @@ NS_ASSUME_NONNULL_BEGIN
 @property (assign, nonatomic) NSTimeInterval defaultNotInUseTimeout;
 
 - (METSubscription *)addSubscriptionWithName:(NSString *)name parameters:(nullable NSArray *)parameters completionHandler:(nullable METSubscriptionCompletionHandler)completionHandler;
-- (void)removeSubscription:(METSubscription *)subscription;
+- (void)removeSubscription:(METSubscription *)subscription immediately:(BOOL)immediately completionHandler:(nullable METSubscriptionCompletionHandler)completionHandler;
 
 - (void)didReceiveReadyForSubscriptionWithID:(NSString *)subscriptionID;
 - (void)didReceiveNosubForSubscriptionWithID:(NSString *)subscriptionID error:(NSError *)error;

Meteor/METSubscriptionManager.m

@@ -35,6 +35,8 @@ @interface METSubscriptionManager ()
 
 @end
 
+NSString * const METSubscriptionManagerErrorDomain = @"com.meteor.SubscriptionManager.ErrorDomain";
+
 @implementation METSubscriptionManager {
   dispatch_queue_t _queue;
   NSMutableDictionary *_subscriptionsByID;
@@ -97,7 +99,7 @@ - (METSubscription *)existingSubscriptionWithName:(NSString *)name parameters:(N
   return existingSubscription;
 }
 
-- (void)removeSubscription:(METSubscription *)subscription {
+- (void)removeSubscription:(METSubscription *)subscription immediately:(BOOL)immediately completionHandler:(nullable METSubscriptionCompletionHandler)completionHandler {
   NSParameterAssert(subscription);
 
   dispatch_async(_queue, ^{
@@ -106,25 +108,40 @@ - (void)removeSubscription:(METSubscription *)subscription {
     if (!subscription.inUse) {
       [self removeSubscriptionToBeRevivedAfterConnect:subscription];
 
-      if (subscription.reuseTimer == nil) {
-        subscription.reuseTimer = [[METTimer alloc] initWithQueue:_queue block:^{
-          // Subscription was reused before timeout
-          if (subscription.inUse) {
-            return;
-          }
-          
-          [_subscriptionsByID removeObjectForKey:subscription.identifier];
-          
-          if (_client.connected) {
-            [_client sendUnsubMessageForSubscription:subscription];
-          }
-        }];
+      if (immediately) {
+        [self removeSubscription:subscription completionHandler:completionHandler];
+      } else {
+        if (subscription.reuseTimer == nil) {
+          subscription.reuseTimer = [[METTimer alloc] initWithQueue:_queue block:^{
+            // Subscription was reused before timeout
+            if (subscription.inUse) {
+              return;
+            }
+            [self removeSubscription:subscription completionHandler:completionHandler];
+          }];
+        }
+        [subscription.reuseTimer startWithTimeInterval:subscription.notInUseTimeout];
       }
-      [subscription.reuseTimer startWithTimeInterval:subscription.notInUseTimeout];
     }
   });
 }
 
+- (void)removeSubscription:(METSubscription *)subscription completionHandler:(METSubscriptionCompletionHandler)completionHandler {
+    [_subscriptionsByID removeObjectForKey:subscription.identifier];
+    
+    NSError *error = nil;
+    
+    if (_client.connected) {
+        [_client sendUnsubMessageForSubscription:subscription];
+    } else {
+        error = [NSError errorWithDomain:METSubscriptionManagerErrorDomain code:0 userInfo:@{NSLocalizedDescriptionKey: @"Client is not connected"}];
+    }
+    
+    if (completionHandler) {
+        completionHandler(error);
+    }
+}
+
 - (void)didReceiveReadyForSubscriptionWithID:(NSString *)subscriptionID {
   NSParameterAssert(subscriptionID);