more docs and clean up

packages/in_app_purchase/in_app_purchase_storekit/darwin/Classes/StoreKit2/InAppPurchaseStoreKit2.swift

@@ -102,7 +102,7 @@ extension InAppPurchasePlugin: InAppPurchase2API {
   func finish(id: Int64, completion: @escaping (Result<Void, any Error>) -> Void) {
     Task {
       print("native finish")
-      let transaction = try await fetchTransaction(by: UInt64(id));
+      let transaction = try await fetchTransaction(by: UInt64(id))
       if let transaction = transaction {
         await transaction.finish()
       }
@@ -151,16 +151,16 @@ extension InAppPurchasePlugin: InAppPurchase2API {
   }
 
   func fetchTransaction(by id: UInt64) async throws -> Transaction? {
-      for await result in Transaction.all {
-          switch result {
-          case .verified(let transaction):
-              if transaction.id == id {
-                  return transaction
-              }
-          case .unverified(_, _):
-              continue
-          }
+    for await result in Transaction.all {
+      switch result {
+      case .verified(let transaction):
+        if transaction.id == id {
+          return transaction
+        }
+      case .unverified(_, _):
+        continue
       }
-      return nil
+    }
+    return nil
   }
 }

packages/in_app_purchase/in_app_purchase_storekit/example/ios/RunnerTests/InAppPurchaseStoreKit2PluginTests.swift

@@ -98,6 +98,8 @@ final class InAppPurchase2PluginTests: XCTestCase {
   }
 
   func testSuccessfulPurchase() async throws {
-    plugin.purchase(id: <#T##String#>, options: nil, completion: <#T##(Result<SK2ProductPurchaseResultMessage, any Error>) -> Void#>)
+    plugin.purchase(
+      id: <#T##String#>, options: nil,
+      completion: <#T##(Result<SK2ProductPurchaseResultMessage, any Error>) -> Void#>)
   }
 }

packages/in_app_purchase/in_app_purchase_storekit/lib/src/in_app_purchase_storekit_platform.dart

@@ -40,7 +40,7 @@ class InAppPurchaseStoreKitPlatform extends InAppPurchasePlatform {
 
   @override
   Stream<List<PurchaseDetails>> get purchaseStream => _useStoreKit2
-      ? _sk2transactionObserver.purchaseUpdatedController.stream
+      ? _sk2transactionObserver.transactionsCreatedController.stream
       : _observer.purchaseUpdatedController.stream;
 
   /// Callback handler for transaction status changes.
@@ -66,8 +66,8 @@ class InAppPurchaseStoreKitPlatform extends InAppPurchasePlatform {
         onListen: () => SK2Transaction.startListeningToTransactions(),
         onCancel: () => SK2Transaction.stopListeningToTransactions(),
       );
-      _sk2transactionObserver =
-          SK2TransactionObserver(purchaseUpdatedController: updateController2);
+      _sk2transactionObserver = SK2TransactionObserver(
+          transactionsCreatedController: updateController2);
       InAppPurchase2CallbackAPI.setUp(_sk2transactionObserver);
     } else {
       // Create a purchaseUpdatedController and notify the native side when to

packages/in_app_purchase/in_app_purchase_storekit/lib/src/store_kit_2_wrappers/sk2_product_wrapper.dart

@@ -3,7 +3,6 @@
 // found in the LICENSE file.
 
 import 'package:flutter/services.dart';
-import 'package:in_app_purchase_platform_interface/in_app_purchase_platform_interface.dart';
 import '../../store_kit_2_wrappers.dart';
 
 InAppPurchase2API _hostApi = InAppPurchase2API();
@@ -270,19 +269,30 @@ extension on SK2PriceLocaleMessage {
 enum SK2ProductPurchaseResult {
   /// The purchase succeeded and results in a transaction.
   success,
+
   /// The user canceled the purchase.
   userCancelled,
+
   /// The purchase is pending, and requires action from the customer.
   pending
 }
 
+/// Wrapper around [PurchaseOption]
+/// https://developer.apple.com/documentation/storekit/product/purchaseoption
 class SK2ProductPurchaseOptions {
+  /// Creates a new instance of [SK2ProductPurchaseOptions]
   SK2ProductPurchaseOptions({this.appAccountToken, this.quantity});
+
+  /// Sets a UUID to associate the purchase with an account in your system.
   final String? appAccountToken;
+
+  /// Indicates the quantity of items the customer is purchasing.
   final int? quantity;
 
+  /// Convert to pigeon representation [SK2ProductPurchaseOptionsMessage]
   SK2ProductPurchaseOptionsMessage convertToPigeon() {
-    return SK2ProductPurchaseOptionsMessage();
+    return SK2ProductPurchaseOptionsMessage(
+        appAccountToken: appAccountToken, quantity: quantity);
   }
 }
 
@@ -297,17 +307,6 @@ extension on SK2ProductPurchaseResultMessage {
         return SK2ProductPurchaseResult.pending;
     }
   }
-
-  PurchaseStatus convertToPurchaseStatus() {
-    switch (this) {
-      case SK2ProductPurchaseResultMessage.success:
-        return PurchaseStatus.purchased;
-      case SK2ProductPurchaseResultMessage.userCancelled:
-        return PurchaseStatus.canceled;
-      case SK2ProductPurchaseResultMessage.pending:
-        return PurchaseStatus.pending;
-    }
-  }
 }
 
 /// A wrapper around StoreKit2's [Product](https://developer.apple.com/documentation/storekit/product).
@@ -370,6 +369,9 @@ class SK2Product {
         .toList();
   }
 
+  /// Wrapper for StoreKit's [Product.purchase]
+  /// https://developer.apple.com/documentation/storekit/product/3791971-purchase
+  /// Initiates a purchase for the product with the App Store and displays the confirmation sheet.
   static Future<SK2ProductPurchaseResult> purchase(String id,
       {SK2ProductPurchaseOptions? options}) async {
     SK2ProductPurchaseResultMessage result;

packages/in_app_purchase/in_app_purchase_storekit/lib/src/store_kit_2_wrappers/sk2_transaction_wrapper.dart

@@ -106,23 +106,26 @@ extension on SK2TransactionMessage {
       verificationData: PurchaseVerificationData(
           localVerificationData: '', serverVerificationData: '', source: ''),
       transactionDate: '',
-      // Note that with sk2, any transactions that *can* be returned will require to be finished, and are already purchased.
-      // So set this
-      // as purchased for all transactions initially.
+      // Note that with sk2, any transactions that *can* be returned will
+      // require to be finished, and are already purchased.
+      // So set this as purchased for all transactions initially.
       status: restoring ? PurchaseStatus.restored : PurchaseStatus.purchased,
       purchaseID: id.toString(),
     );
   }
 }
 
-/// An observer that listens to all transactions used
+/// An observer that listens to all transactions created
 class SK2TransactionObserver implements InAppPurchase2CallbackAPI {
-  SK2TransactionObserver({required this.purchaseUpdatedController});
+  /// Creates a new instance of [SK2TransactionObserver]
+  SK2TransactionObserver({required this.transactionsCreatedController});
 
-  final StreamController<List<PurchaseDetails>> purchaseUpdatedController;
+  /// The transactions stream to listen to
+  final StreamController<List<PurchaseDetails>> transactionsCreatedController;
 
   @override
   void onTransactionsUpdated(SK2TransactionMessage newTransaction) {
-    purchaseUpdatedController.add([newTransaction.convertToDetails()]);
+    transactionsCreatedController
+        .add(<PurchaseDetails>[newTransaction.convertToDetails()]);
   }
 }

packages/in_app_purchase/in_app_purchase_storekit/lib/src/types/app_store_purchase_details.dart

@@ -78,6 +78,8 @@ class AppStorePurchaseDetails extends PurchaseDetails {
   bool get pendingCompletePurchase => _pendingCompletePurchase;
 }
 
+/// The class represents the information of a purchase made with the Apple
+/// AppStore, when using Storekit2
 class SK2PurchaseDetails extends PurchaseDetails {
   SK2PurchaseDetails(
       {required super.productID,
@@ -87,6 +89,5 @@ class SK2PurchaseDetails extends PurchaseDetails {
       required super.status});
 
   @override
-  // but not restored
   bool get pendingCompletePurchase => status == PurchaseStatus.purchased;
 }