Improve receipt refreshing (https://github.com/tikhop/TPInAppReceipt/issues/93)

Sources/Extras.swift

@@ -138,7 +138,10 @@ public extension InAppReceipt
     @available(watchOSApplicationExtension 6.2, *)
     static func refresh(completion: @escaping IAPRefreshRequestResult)
     {
-        if refreshSession != nil { return }
+        if refreshSession != nil
+		{
+			return
+		}
         
         refreshSession = RefreshSession()
         refreshSession!.refresh { (error) in
@@ -147,12 +150,28 @@ public extension InAppReceipt
         }
     }
 
+	///  Cancel refreshing local in-app receipt
+	@available(watchOSApplicationExtension 6.2, *)
+	static func cancelRefreshSession()
+	{
+		refreshSession?.cancel()
+	}
+	
     @available(watchOSApplicationExtension 6.2, *)
     static fileprivate func destroyRefreshSession()
     {
         refreshSession = nil
     }
 	
+	/// Check whether receipt is refreshing now
+	///
+	/// - Returns `true` if receipt is refreshing now, otherwise `false`
+	@available(watchOSApplicationExtension 6.2, *)
+	static var isReceiptRefreshingNow: Bool
+	{
+		refreshSession != nil
+	}
+	
 	/// Check whether user is eligible for introductory offer for any products within the same subscription group
 	///
 	/// - Returns `false` if user isn't eligible for introductory offer, otherwise `true`
@@ -174,7 +193,6 @@ fileprivate class RefreshSession : NSObject, SKRequestDelegate
     private let receiptRefreshRequest = SKReceiptRefreshRequest()
     private var completion: IAPRefreshRequestResult?
     
-    
     override init()
     {
         super.init()
@@ -205,10 +223,15 @@ fileprivate class RefreshSession : NSObject, SKRequestDelegate
     func requestDidFinish(with error: Error?)
     {
         DispatchQueue.main.async { [weak self] in
-            self?.completion?(error)
+			self?.completion?(error)
         }
         receiptRefreshRequest.cancel()
     }
+	
+	func cancel()
+	{
+		receiptRefreshRequest.cancel()
+	}
 }
 
 #endif

Sources/IARError.swift

@@ -18,7 +18,7 @@ public enum IARError: Error
     case initializationFailed(reason: ReceiptInitializationFailureReason)
     case validationFailed(reason: ValidationFailureReason)
     case purchaseExpired
-	
+	case receiptRefreshingInProgress
     /// The underlying reason the receipt initialization error occurred.
     ///
     /// - appStoreReceiptNotFound:         In-App Receipt not found

TPInAppReceipt.podspec

@@ -1,7 +1,7 @@
 Pod::Spec.new do |s|
 
 	s.name         = "TPInAppReceipt"
-	s.version      = "3.3.0"
+	s.version      = "3.3.1"
 	s.summary      = "Reading and Validating In App Purchase Receipt Locally"
 	s.description  = "A lightweight iOS/OSX library for reading and validating Apple In App Purchase Receipt locally. Pure swift, No OpenSSL!"