Add context-based function functions

Author: danielsaidi

RELEASE_NOTES.md

@@ -11,13 +11,14 @@ This version makes StoreKitPlus use Swift 6.
 
 ### ‼️ Important information
 
-As a result of the Swift 6 transition, and due to data race problems, the store services no longer takes a context and keeps it in sync. This must be explicitly handled by the caller.
+As a result of the Swift 6 transition, and due to data race problems, the store services no longer takes a context and keeps it in sync. This must be explicitly handled by the caller, for instance using the new context-based functions.
 
 Furthermore, the service model is drastically simplified in this version. Instead of having multiple service types, `StoreService` handles it all.
 
 ### ✨ Features
 
 * `StoreService` has new `.standard` shorthands.
+* `StoreService` has new `context`-based function versions.
 * `StandardStoreService` no longer accepts a context, and will no longer keep it in sync.
 
 ### 🗑️ Deprecations

Sources/StoreKitPlus/Data/Persisted.swift

@@ -70,9 +70,10 @@ open class StandardStoreService: StoreService {
         try await Product.products(for: productIds)
     }
 
+    @discardableResult
     open func purchase(
         _ product: Product
-    ) async throws -> Product.PurchaseResult {
+    ) async throws -> (Product.PurchaseResult, Transaction?) {
         #if os(visionOS)
         throw StoreServiceError.unsupportedPlatform("This purchase operation is not supported in visionOS: Use @Environment(\\.purchase) instead.")
         #else
@@ -83,7 +84,7 @@ open class StandardStoreService: StoreService {
         case .userCancelled: break
         @unknown default: break
         }
-        return result
+        return (result, nil)
         #endif
     }
 

Sources/StoreKitPlus/Services/StandardStoreService.swift

@@ -21,9 +21,10 @@ public protocol StoreService {
     func getProducts() async throws -> [Product]
 
     /// Purchase a certain product.
+    @discardableResult
     func purchase(
         _ product: Product
-    ) async throws -> Product.PurchaseResult
+    ) async throws -> (Product.PurchaseResult, Transaction?)
 
     /// Restore previous purchases.
     @discardableResult
@@ -35,11 +36,40 @@ public protocol StoreService {
     ) async throws
 }
 
+public extension StoreService {
+
+    /// Purchase a certain product.
+    ///
+    /// This function will sync the result to the context.
+    @discardableResult
+    func purchase(
+        _ product: Product,
+        syncWith context: StoreContext
+    ) async throws -> (Product.PurchaseResult, Transaction?) {
+        let result = try await purchase(product)
+        if let transaction = result.1 {
+            await context.updatePurchaseTransactions(with: transaction)
+        }
+        return result
+    }
+
+    /// Restore previous purchases.
+    ///
+    /// This function will sync the result to the context.
+    @discardableResult
+    func restorePurchases(
+        syncWith context: StoreContext
+    ) async throws -> [Transaction] {
+        let result = try await restorePurchases()
+        await context.updatePurchaseTransactions(result)
+        return result
+    }
+}
+
 public extension StoreService {
 
     @available(*, deprecated, message: "You have to pass in a context now.")
     func syncStoreData() async throws {
         try await syncStoreData(to: .init())
     }
 }
-

Sources/StoreKitPlus/Services/StoreService.swift

@@ -125,3 +125,34 @@ private extension StoreContext {
 
     static func key(_ name: String) -> String { "com.danielsaidi.storekitplus.\(name)" }
 }
+
+/// This property wrapper automatically persists a new value
+/// to user defaults.
+@propertyWrapper
+struct Persisted<T: Codable> {
+
+    init(
+        key: String,
+        store: UserDefaults = .standard,
+        defaultValue: T) {
+        self.key = key
+        self.store = store
+        self.defaultValue = defaultValue
+    }
+
+    private let key: String
+    private let store: UserDefaults
+    private let defaultValue: T
+
+    var wrappedValue: T {
+        get {
+            guard let data = store.object(forKey: key) as? Data else { return defaultValue }
+            let value = try? JSONDecoder().decode(T.self, from: data)
+            return value ?? defaultValue
+        }
+        set {
+            let data = try? JSONEncoder().encode(newValue)
+            store.set(data, forKey: key)
+        }
+    }
+}