React Native / Swift - In App Purchases code crashing randomly in sandbox and testflight

Question

I am trying to include in app purchases in a react native app. I have tried react-native-in-app-utils and creating a native module in Swift. Both work but both seem very unstable. Random crashes with no errors in the Xcode console. Much more stable on test-flight but still crashes and seems to have no rhyme or reason. The bulk of the crashes happen on purchasing, but also happens a lot when retrieving purchases from Apple or restoring purchases. Here is my swift code for which I have an Objective C bridge to react-native:

// Create Product List
struct ProductList {
  static let monthlySub       : String  = "monthlysubscription"
  static let threeMonthlySub  : String  = "threemonthlysubscription"
  static let sixMonthlySub    : String  = "sixmonthlysubscription"
  static let yearlySub        : String  = "yearlysubscription"

  static let products = [monthlySub, threeMonthlySub, sixMonthlySub, yearlySub]
}

@objc(StoreManager)
class StoreManager: NSObject {

  var loadedProducts: Dictionary<String, SKProduct> = [:]
  // callback holders defined as optionals
  var purchaseCallbackHolder: RCTResponseSenderBlock? = nil
  var productsCallbackHolder: RCTResponseSenderBlock? = nil
  var restoreCallbackHolder: RCTResponseSenderBlock? = nil

  override init() {
    super.init()
    SKPaymentQueue.defaultQueue().addTransactionObserver(self)
  }

  @objc func getProductList(name: String, callback successCallback: RCTResponseSenderBlock){
    // check payments allowed
    if SKPaymentQueue.canMakePayments() {
      // products from static struct
      let products = NSSet(array: ProductList.products);
      // When request completes, calls the SKProductsRequestDelegate
      let request = SKProductsRequest(productIdentifiers: products as! Set<String>);
      productsCallbackHolder = successCallback
      request.delegate = self;
      request.start();
    }
  }

  @objc func purchaseProduct(productIdentifier: String, callback successCallback: RCTResponseSenderBlock) {
    let product = loadedProducts[productIdentifier as String]!
    let payment = SKPayment(product: product)
    // add callback to holder
    purchaseCallbackHolder = successCallback
    // Triggers SKPaymentTransactionObserver
    SKPaymentQueue.defaultQueue().addPayment(payment)
  }

  @objc func restorePurchases(name:String, callback successCallback: RCTResponseSenderBlock){
    restoreCallbackHolder = successCallback
    print("Restoring Purchases")
    SKPaymentQueue.defaultQueue().restoreCompletedTransactions()
  }


  @objc func validatePurchases(name:String, callback successCallback: RCTResponseSenderBlock) -> Void {

    let receiptUrl = NSBundle.mainBundle().appStoreReceiptURL
    let receipt: NSData = NSData(contentsOfURL:receiptUrl!)!
    let receiptdata: NSString = receipt.base64EncodedStringWithOptions(NSDataBase64EncodingOptions(rawValue: 0))

    // Pass Base64 encoded string back to JS
    successCallback([receiptdata])

  }

  func updateWithProducts(products: [SKProduct]) {

    var productIdentifiers: Dictionary<String, NSNumber> = [:]
    for product in products {
      loadedProducts[product.productIdentifier] = product
      productIdentifiers[product.productIdentifier] = product.price
    }
    productsCallbackHolder?([productIdentifiers])
  }


}

extension StoreManager: SKProductsRequestDelegate {
  func productsRequest(request: SKProductsRequest, didReceiveResponse response: SKProductsResponse) {
    // products retrieved from App store
    let appProducts = response.products
    if appProducts.count != 0 {
      for product in appProducts{
        print(product.productIdentifier)
      }
      print(appProducts)
      updateWithProducts(appProducts)
    }
    else {
      // return error/info to react native
      print("no products received from store")
    }
  }
}
extension StoreManager: SKPaymentTransactionObserver {
  func paymentQueue(queue: SKPaymentQueue, updatedTransactions transactions: [SKPaymentTransaction])    {
    print("Received Payment Transaction Response from Apple");
    for transaction:AnyObject in transactions {
      // check object is a transaction first
      if let trans:SKPaymentTransaction = transaction as? SKPaymentTransaction{
        switch trans.transactionState {
        case .Purchased:
          print("Product Purchased");
          SKPaymentQueue.defaultQueue().finishTransaction(transaction as! SKPaymentTransaction)
          break;
        case .Failed:
          print("Purchased Failed");
          SKPaymentQueue.defaultQueue().finishTransaction(transaction as! SKPaymentTransaction)
          break;
        case .Restored:
          print("Purchases Restored");
          SKPaymentQueue.defaultQueue().finishTransaction(transaction as! SKPaymentTransaction)
        default:
          break;
        }
      }
      // invoke any callback waiting to be called
      purchaseCallbackHolder?([])
      purchaseCallbackHolder = nil
      restoreCallbackHolder?([])
      restoreCallbackHolder = nil
    }

  }
}

Any help would be much appreciated!

Update: I have a stack trace of the crash below

AppName[1788:581487] *** -[StoreManager respondsToSelector:]: message sent to deallocated instance 0x14d43f80
(lldb) bt
* thread #4: tid = 0x8df6f, 0x25750ffe CoreFoundation`___forwarding___ + 530, queue = 'com.facebook.react.StoreManagerQueue', stop reason = EXC_BREAKPOINT (code=EXC_ARM_BREAKPOINT, subcode=0xdefe)
  * frame #0: 0x25750ffe CoreFoundation`___forwarding___ + 530
    frame #1: 0x2567b298 CoreFoundation`_CF_forwarding_prep_0 + 24
    frame #2: 0x2f103f1e StoreKit`__NotifyObserverAboutChanges + 66
    frame #3: 0x2565bc08 CoreFoundation`CFArrayApplyFunction + 36
    frame #4: 0x2f103ecc StoreKit`-[SKPaymentQueue _notifyObserversAboutChanges:sendUpdatedDownloads:] + 128
    frame #5: 0x2f1028e8 StoreKit`-[SKPaymentQueue addPayment:] + 320
    frame #6: 0x00106438 AppName`StoreManager.purchaseProduct(productIdentifier="iosmonthlysubscription799", successCallback=0x00106694 AppName`partial apply forwarder for reabstraction thunk helper from @callee_unowned @convention(block) (@unowned Swift.ImplicitlyUnwrappedOptional<__ObjC.NSArray>) -> (@unowned ()) to @callee_owned (@owned Swift.ImplicitlyUnwrappedOptional<Swift.Array<Swift.AnyObject>>) -> (@unowned ()) with unmangled suffix ".40" at inAppPayments.swift, self=0x14d0a990) -> ()) -> () + 1168 at inAppPayments.swift:54
    frame #7: 0x00106634 AppName`@objc StoreManager.purchaseProduct(String, callback : ([AnyObject]!) -> ()) -> () + 240 at inAppPayments.swift:0
    frame #8: 0x25752664 CoreFoundation`__invoking___ + 68
    frame #9: 0x256778bc CoreFoundation`-[NSInvocation invoke] + 292
    frame #10: 0x2567b356 CoreFoundation`-[NSInvocation invokeWithTarget:] + 50
    frame #11: 0x001672d6 AppName`-[RCTModuleMethod invokeWithBridge:module:arguments:](self=0x14fdba90, _cmd="invokeWithBridge:module:arguments:", bridge=0x14faa1a0, module=0x14d0a990, arguments=@"2 elements") + 1636 at RCTModuleMethod.m:489
    frame #12: 0x001abaea AppName`-[RCTBatchedBridge _handleRequestNumber:moduleID:methodID:params:](self=0x14faa1a0, _cmd="_handleRequestNumber:moduleID:methodID:params:", i=6, moduleID=77, methodID=3, params=@"2 elements") + 926 at RCTBatchedBridge.m:987
    frame #13: 0x001aae44 AppName`__33-[RCTBatchedBridge handleBuffer:]_block_invoke.452(.block_descriptor=<unavailable>) + 1028 at RCTBatchedBridge.m:915
    frame #14: 0x00b9bba6 libdispatch.dylib`_dispatch_call_block_and_release + 10
    frame #15: 0x00ba64aa libdispatch.dylib`_dispatch_queue_drain + 2014
    frame #16: 0x00b9ede2 libdispatch.dylib`_dispatch_queue_invoke + 282
    frame #17: 0x00ba799e libdispatch.dylib`_dispatch_root_queue_drain + 426
    frame #18: 0x00ba77f0 libdispatch.dylib`_dispatch_worker_thread3 + 100
    frame #19: 0x2547ee0c libsystem_pthread.dylib`_pthread_wqthread + 1024
    frame #20: 0x2547e9fc libsystem_pthread.dylib`start_wqthread + 8

Seems to be crashing because my callback references are optionals? This is Swift which is called by an Objective C bridge. I believe Objective C has no concept of optionals.

var purchaseCallbackHolder: RCTResponseSenderBlock? = nil

Is there a better way to do this? Thanks again

Answer 1

The transaction observer needs to be removed in a deinit method:

  override init() {
    super.init()
    SKPaymentQueue.defaultQueue().addTransactionObserver(self)
  }


  deinit {
    if SKPaymentQueue.canMakePayments() {
      SKPaymentQueue.defaultQueue().removeTransactionObserver(self)
    }
  }

I looked up the errors I was getting in my stack trace and one of them:

StoreKit__NotifyObserverAboutChanges

Pointed me to this article: A single bug in my StoreKit code that lost me 90% of IAP sales