Bug Fix clearTransaction promise

Added a promise to the clearTransaction function, to wait until it finishes clearing open transactions

dooboolab-community#1120

ios/RNIapIos.m

@@ -255,11 +255,23 @@ - (BOOL)paymentQueue:(SKPaymentQueue *)queue shouldAddStorePayment:(SKPayment *)
     }
 }
 
-RCT_EXPORT_METHOD(clearTransaction) {
-    NSArray *pendingTrans = [[SKPaymentQueue defaultQueue] transactions];
+RCT_EXPORT_METHOD(clearTransaction:(RCTPromiseResolveBlock)resolve
+                  reject:(RCTPromiseRejectBlock)reject) {  
+
     NSLog(@"\n\n\n  ***  clear remaining Transactions. Call this before make a new transaction   \n\n.");
-    for (int k = 0; k < pendingTrans.count; k++) {
-        [[SKPaymentQueue defaultQueue] finishTransaction:pendingTrans[k]];
+
+    NSArray *pendingTrans = [[SKPaymentQueue defaultQueue] transactions];
+    countPendingTransaction = (NSInteger)(pendingTrans.count);
+
+    if (countPendingTransaction > 0) {
+        [self addPromiseForKey:@"cleaningTransactions" resolve:resolve reject:reject];
+
+        for (SKPaymentTransaction *transaction in pendingTrans) {
+            [[SKPaymentQueue defaultQueue] finishTransaction:transaction];
+        }
+
+    } else {
+        resolve(nil);
     }
 }
 
@@ -814,4 +826,15 @@ - (void)requestDidFinish:(SKRequest *)request {
     }
 }
 
+-(void)paymentQueue:(SKPaymentQueue *)queue removedTransactions:(NSArray *)transactions {
+    NSLog(@"removedTransactions");
+    if (countPendingTransaction != nil && countPendingTransaction > 0) {
+        countPendingTransaction--;
+        if (countPendingTransaction == 0) {
+            [self resolvePromisesForKey:@"cleaningTransactions" value:nil];
+            countPendingTransaction = nil;
+        }
+    }
+}
+
 @end