Use-cases for Swift interop in .NET 10

Overview

This issue presents use-cases we want to support. They are required to define and limit the scope of Swift interop effort in .NET 10. While it's difficult to clearly specify the exact Swift language features that will be supported in the next release, we can establish our definition of done, with focus on two key areas: functionality and performance.

Hiking app

We want to develop an experimental .NET iOS app which will serve as a base for implementing use-cases that showcase the capabilities of Swift interop. Selected functionalities from the app will be calling into Swift-only frameworks to demonstrate capabilities of the Swift interop. The app and corresponding bindings will not be officially supported.

Users of the app will be able to explore trails, authenticate using Apple ID, purchase a trail, and record a hike.

In-app purchase example

This example demonstrates in-app purchases and reviews using StoreKit2 framework. On the "Explore" page, items will be available for purchase via the products method. When the purchase button is clicked, it triggers the purchase method. Target APIs: - [ ] PaymentMethodBinding ```swift struct PaymentMethodBinding : Swift.Sendable, Swift.Hashable, Swift.Identifiable {} ``` - [ ] Transaction ```swift struct Transaction : Swift.Identifiable {} ``` - [ ] Reason ```swift struct Reason : Swift.RawRepresentable, Swift.Equatable, Swift.Hashable, Swift.Sendable {} ``` - [ ] RevocationReason ```swift struct RevocationReason : Swift.RawRepresentable, Swift.Equatable, Swift.Hashable {} ``` - [ ] OfferType ```swift struct OfferType : Swift.RawRepresentable, Swift.Equatable, Swift.Hashable {} ``` - [ ] OwnershipType ```swift struct OwnershipType : Swift.RawRepresentable, Swift.Equatable, Swift.Hashable {} ``` - [ ] Offer ```swift struct Offer : Swift.Equatable, Swift.Hashable, Swift.Sendable {} ``` - [ ] PaymentMode ```swift struct PaymentMode : Swift.RawRepresentable, Swift.Equatable, Swift.Hashable, Swift.Sendable {} ``` - [ ] Transactions ```swift struct Transactions : _Concurrency.AsyncSequence {} ``` - [ ] AsyncIterator ```swift struct AsyncIterator : _Concurrency.AsyncIteratorProtocol {} ``` - [ ] Environment ```swift struct Environment : Swift.RawRepresentable, Swift.Equatable, Swift.Hashable, Swift.Sendable {} ``` - [ ] PurchaseIntent ```swift struct PurchaseIntent : Swift.Equatable, Swift.Identifiable, Swift.Sendable {} ``` - [ ] PurchaseIntents ```swift struct PurchaseIntents : _Concurrency.AsyncSequence {} ``` - [ ] Storefront ```swift struct Storefront : Swift.Identifiable, Swift.Sendable {} ``` - [ ] Storefronts ```swift struct Storefronts : _Concurrency.AsyncSequence, Swift.Sendable {} ``` - [ ] SubscriptionPeriod ```swift struct SubscriptionPeriod : Swift.Equatable, Swift.Hashable {} ``` - [ ] FormatStyle ```swift struct FormatStyle : Foundation.FormatStyle {} ``` - [ ] SubscriptionOffer ```swift struct SubscriptionOffer : Swift.Equatable, Swift.Hashable {} ``` - [ ] Signature ```swift struct Signature : Swift.Equatable, Swift.Hashable, Swift.Sendable {} ``` - [ ] Token ```swift struct Token : Swift.Hashable, Swift.Sendable {} ``` - [ ] RenewalState ```swift struct RenewalState : Swift.RawRepresentable, Swift.Equatable, Swift.Hashable {} ``` - [ ] RenewalInfo ```swift struct RenewalInfo {} ``` - [ ] ExpirationReason ```swift struct ExpirationReason : Swift.RawRepresentable, Swift.Equatable, Swift.Hashable {} ``` - [ ] Status ```swift struct Status : Swift.Equatable, Swift.Hashable {} ``` - [ ] Statuses ```swift struct Statuses : _Concurrency.AsyncSequence {} ``` - [ ] PromotionInfo ```swift struct PromotionInfo : Swift.Equatable {} ``` - [ ] AppTransaction ```swift struct AppTransaction : Swift.Sendable {} ``` - [ ] SubscriptionInfo ```swift struct SubscriptionInfo : Swift.Equatable, Swift.Hashable {} ``` - [ ] Message ```swift struct Message : Swift.Sendable {} ``` - [ ] Messages ```swift struct Messages : _Concurrency.AsyncSequence, Swift.Sendable {} ``` - [ ] PurchaseOption ```swift struct PurchaseOption : Swift.Equatable, Swift.Hashable {} ``` - [ ] Product ```swift struct Product : Swift.Identifiable {} ``` - [ ] ProductType ```swift struct ProductType : Swift.RawRepresentable, Swift.Equatable, Swift.Hashable {} ``` - [ ] PaymentMethodBindingError ```swift enum PaymentMethodBindingError : Foundation.LocalizedError {} ``` - [ ] RefundRequestError ```swift enum RefundRequestError : Swift.Error {} ``` - [ ] RefundRequestStatus ```swift enum RefundRequestStatus {} ``` - [ ] AppStore ```swift enum AppStore {} ``` - [ ] Unit ```swift enum Unit : Swift.Equatable, Swift.Hashable {} ``` - [ ] ExternalPurchase ```swift enum ExternalPurchase : Swift.Sendable {} ``` - [ ] NoticeResult ```swift enum NoticeResult : Swift.Hashable, Swift.Sendable {} ``` - [ ] ExternalPurchaseLink ```swift enum ExternalPurchaseLink : Swift.Sendable {} ``` - [ ] ExternalLinkAccount ```swift enum ExternalLinkAccount : Swift.Sendable {} ``` - [ ] ExternalPurchaseCustomLink ```swift enum ExternalPurchaseCustomLink : Swift.Sendable {} ``` - [ ] NoticeType ```swift enum NoticeType : Swift.Int, Swift.Hashable, Swift.Sendable {} ``` - [ ] PriceIncreaseStatus ```swift enum PriceIncreaseStatus : Swift.Equatable, Swift.Hashable {} ``` - [ ] VerificationResult ```swift enum VerificationResult {} ``` - [ ] VerificationError ```swift enum VerificationError : Swift.Error {} ``` - [ ] Visibility ```swift enum Visibility : Swift.Int, Swift.Equatable, Swift.Hashable {} ``` - [ ] StoreKitError ```swift enum StoreKitError : Swift.Error {} ``` - [ ] BackingValue ```swift enum BackingValue : Swift.Equatable, Swift.Hashable {} ``` - [ ] PurchaseResult ```swift enum PurchaseResult {} ``` - [ ] PrchaseError ```swift enum PurchaseError : Swift.Error {} ```

Authentication example

This example demonstrates the authentication feature using the built-in [SignInWithAppleButton](https://developer.apple.com/documentation/authenticationservices/signinwithapplebutton) on the “Login” page. Users can authenticate using their Apple ID, providing a seamless login experience. Target APIs: - [ ] SignInWithAppleButton ```swift @_Concurrency.MainActor @preconcurrency struct SignInWithAppleButton : SwiftUICore.View {} ``` - [ ] SignInWithAppleButton.Label ```swift struct Label { public static let signIn: _AuthenticationServices_SwiftUI.SignInWithAppleButton.Label public static let `continue`: _AuthenticationServices_SwiftUI.SignInWithAppleButton.Label public static let signUp: _AuthenticationServices_SwiftUI.SignInWithAppleButton.Label } ``` - [ ] SignInWithAppleButton.Style ```swift struct Label { public static let black: _AuthenticationServices_SwiftUI.SignInWithAppleButton.Style public static let white: _AuthenticationServices_SwiftUI.SignInWithAppleButton.Style public static let whiteOutline: _AuthenticationServices_SwiftUI.SignInWithAppleButton.Style } ```

SwiftUI views example

This example demonstrates how .NET developers can integrate native SwiftUI controls into MAUI-based applications, leveraging native UI controls for a seamless user experience. This example implements SwiftUI views and serves as a foundation for the next examples. The “Login” page includes a login button and text. The main menu contains "Explore" and "My Trails" pages. The "Explore" page displays a list of available trails for purchase. Each item includes an image, text, and a "Buy" button. “Trail details” page displays an image and description. If the trail is not purchased, there is a "Purchase" button and an image; if it is purchased, there is a "Start/Stop" button and a map with start and end pins. Views and controls should be sourced from the SwiftUI framework. Target APIs: - [ ] [Button](https://developer.apple.com/documentation/swiftui/button) - [ ] [Label](https://developer.apple.com/documentation/swiftui/label) - [ ] [Image](https://developer.apple.com/documentation/swiftui/image)

[!NOTE]
The .NET iOS app with generated bindings will be experimental in .NET 10 and will not be officially supported.

Author:	kotlarmilos
Assignees:	kotlarmilos
Labels:	`area-Meta`, `User Story`
Milestone:	9.0.0

dotnet / runtime