Remove presentCodeRedemptionSheet from PaymentQueueWrapper & Use SK2 APIs

[fire-at-will]

Motivation

As a part of supporting win-back offers with Streamlined Purchasing disabled, we need to ensure that we aren't using both the PurchaseIntents API and the paymentQueue(_:shouldAddStorePayment:for:) functions at the same time to comply with this warning from Apple's PurchaseIntent docs:

Important

To enable promoted in-app purchases, your app must use either PurchaseIntent (starting in iOS 16.4) or paymentQueue(_:shouldAddStorePayment:for:) (starting in iOS 11). Don’t use both at the same time. If necessary, use conditional compilation to identify the OS version the app is running in. For more information, see Running code on a specific platform or OS version.

To meet this requirement, we want to ensure that we're not using the PaymentQueueWrapper class when on iOS >=16.4 (when the PurchaseIntents API was introduced) and the SDK is configured to use StoreKit2.

Description

This PR removes the presentCodeRedemptionSheet function from the PaymentQueueWrapperType and replaces its usages with a new OfferCodeRedemptionSheetPresenter struct.

API Changes

The PR deprecates the existing public Purchases.presentCodeRedemptionSheet() function and replaces it with a new function that more closely matches Apple's new API for presenting offer code redemption sheets:

@available(iOS 14.0, *)
@available(macCatalyst, unavailable)
@available(watchOS, unavailable)
@available(tvOS, unavailable)
@available(macOS, unavailable)
func presentCodeRedemptionSheet(uiWindowScene: UIWindowScene?) async throws

The notable changes for this function signature include:

• It's async & throwing
• It accepts an optional UIWindowScene that allows the developer to specify which scene to present the sheet over. If one is not provided, we display the sheet over the currently active scene.

Mac Catalyst & "Designed for iPad" Apps on macOS

According to Apple's presentOfferCodeRedeemSheet docs:

In Mac apps built with Mac Catalyst, this method throws a StoreKitError.unknown error.

In our testing, the StoreKitError.unknown error is also thrown on iOS apps running as "Designed for iPad" on macOS. Due to this error, our new functions:

• Are unavailable for Mac Catalyst
• No-op and log a warning for iOS running as "Designed for iPad" on macOS

Implications for the Hybrids

For now, the hybrids should be okay to continue using the deprecated presentCodeRedemptionSheet function. We can update them to use the new presentCodeRedemptionSheet API by doing the following:

• When async/await isn't available, wrap the call in a Task
• Passing in nil for the uiWindowScene and just presenting over the currently active window scene

Presenting the Offer Code Redemption Sheet on macOS

Apple introduced a new API for showing the code redemption sheet on native (non-iOS, non-catalyst) macOS apps. To keep the scope of this PR down, that functionality will be added in a follow-up PR.

[fire-at-will]

It might be a little awkward that this is possible, but I thought it was important to keep the provided window scene optional for two reasons:

1. So that developers using SwiftUI can use easily the API
2. To keep the new Purchases.presentCodeRedemptionSheet API as similar as possible to the deprecated one

[aboedo]

generally looks great! Left one question

[MarkVillacampa]

Does this mean calling this function of the SDK has been crashing on Catalyst and iOS apps running on macOS?

[fire-at-will]

For Catalyst, nope! Luckily the old version of presentCodeRedemptionSheet() was marked as unavailable on Catalyst (see the definition in the current main branch here.

For "Designed for iPad" on macOS, I haven't tested it myself, but I wouldn't be surprised if the existing SDK function is crashing, since this PR introduces the isiOSAppOnMac check for the first time in the code redemption sheet flow

[MarkVillacampa]

Was the presentCodeRedemptionSheet function moved inside this conditional intentionally? I think this might be a breaking change since it changes where the function is compiled (even if unavailable) so you cannot use runtime availability checks with it.