CODEWITHSUNDEEP
iosswiftasynchronouspromisekit
Tunds
Tunds

Reputation: 1817

PromiseKit unable to hit catch within chain

I'm currently mixing SwiftyStoreKit and PromiseKit in order to handle in-app purchases, the problem/issue I'm having is that within the chain of promises if I throw an error within one of them the catch block isn't being executed/hit when the reject() function is called.

To how I'm chaining these promises, you can see this below. 

     firstly {
        IAPViewModel.retrieveIAPProducts()
     }.then { products in
        IAPViewModel.purchase(products[1])
     }.ensure {
        // This is to silence the warning of values being unused
        _ = IAPViewModel.validatePurchases()
     }.catch { error in
        UIAlertController.show(message: "Error - \(error._code): \(error.localizedDescription)")
     }

An example of a function that's wrapped around a Promise, the best example is probably my purchase function since users can hit cancel and this will throw an error. See below.

static func purchase(_ product: SKProduct) -> Promise<Void> {

    let loftyLoadingViewContentModel =  LoftyLoadingViewContentModel(title: "Purchasing".uppercased(), message: "We’re currently processing your\nrequest, for your subscription.")
    UIApplication.topViewController()?.showLoadingView(.popOverScreen, loftyLoadingViewContentModel)

    return Promise { seal in

        SwiftyStoreKit.purchaseProduct(product) { purchaseResult in

            switch purchaseResult {
            case .success(let product):
                if product.needsFinishTransaction {
                    SwiftyStoreKit.finishTransaction(product.transaction)
                }
                seal.fulfill()
                log.info("Purchase Success: \(product.productId)")
            case .error(let error):
                UIApplication.topViewController()?.removeLoadingView()
                seal.reject(error)
            }
        }
    }
}

I have put a breakpoint in and the error case is being hit when I touch cancel, but this then doesn't trigger the catch block back within the chain of Promises. I can't seem to put my finger on why.

Upvotes: 1

Views: 457

Answers (1)

Tunds
Tunds

Reputation: 1817

Managed to figured it out, I had to explicitly set that I wanted my catch to catch all errors by adding this parameter to the block, (policy: .allErrors).

     firstly {
        IAPViewModel.retrieveIAPProducts()
     }.then { products in
        IAPViewModel.purchase(products[1])
     }.ensure {
        // This is to silence the warning of values being unused
        _ = IAPViewModel.validatePurchases()
     }.catch (policy: .allErrors) { error in
        UIAlertController.show(message: "Error - \(error._code): \(error.localizedDescription)")
     }

Upvotes: 1

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