[in_app_purchase] Fix an issue causing StoreKit 2 transactions remain unfinished (#10656)

The StoreKit 2 (iOS, MacOS) in_app_purchase backend causes ordinary client use (eg. the `in_app_purchase` example app) to leave transactions in an unfinished state, contrary to the StoreKit contract.

This happens because StoreKit 2 purchase updates have `pendingCompletePurchase == false`, causing clients to not call `completePurchase` (flutter/flutter#180046). This in turn happens because purchase updates incorrectly have state `restored` instead of `purchased` (flutter/flutter#172434).

Fix this by keeping track of which TransactionMessages are created in the restorePurchases code path to set the `restoring` field correctly. Previously it was set whenever a transaction had receipt data (which is also true for ordinary purchase updates). This keeps ordinary purcahses as state `purchased`. These purchase records will also have `pendingCompletePurchase` set to `true`, since this is gated by state `purchased`.

Fixes:
* flutter/flutter#180046
* flutter/flutter#172434

## Pre-Review Checklist

[^1]: Regular contributors who have demonstrated familiarity with the repository guidelines only need to comment if the PR is not auto-exempted by repo tooling.

Author: edpizzi

packages/in_app_purchase/in_app_purchase_storekit/CHANGELOG.md

@@ -1,5 +1,7 @@
-## NEXT
+## 0.4.8
 
+* Fixes an issue causing StoreKit2 purchases to be reported as `restored` and left in an
+  unfinished state, due to `pendingCompletePurchase` being false.
 * Fixes Xcode 26.2 analyzer warnings in example app tests.
 
 ## 0.4.7

packages/in_app_purchase/in_app_purchase_storekit/darwin/in_app_purchase_storekit/Sources/in_app_purchase_storekit/StoreKit2/InAppPurchasePlugin+StoreKit2.swift

@@ -261,7 +261,8 @@ extension InAppPurchasePlugin: InAppPurchase2API {
           switch completedPurchase {
           case .verified(let purchase):
             self.sendTransactionUpdate(
-              transaction: purchase, receipt: "\(completedPurchase.jwsRepresentation)")
+              transaction: purchase, receipt: "\(completedPurchase.jwsRepresentation)",
+              restoring: true)
           case .unverified(let failedPurchase, let error):
             unverifiedPurchases[failedPurchase.id] = (
               receipt: completedPurchase.jwsRepresentation, error: error
@@ -354,8 +355,10 @@ extension InAppPurchasePlugin: InAppPurchase2API {
   }
 
   /// Sends an transaction back to Dart. Access these transactions with `purchaseStream`
-  private func sendTransactionUpdate(transaction: Transaction, receipt: String? = nil) {
-    let transactionMessage = transaction.convertToPigeon(receipt: receipt)
+  private func sendTransactionUpdate(
+    transaction: Transaction, receipt: String? = nil, restoring: Bool = false
+  ) {
+    let transactionMessage = transaction.convertToPigeon(receipt: receipt, restoring: restoring)
     Task { @MainActor in
       self.transactionCallbackAPI?.onTransactionsUpdated(newTransactions: [transactionMessage]) {
         result in

packages/in_app_purchase/in_app_purchase_storekit/darwin/in_app_purchase_storekit/Sources/in_app_purchase_storekit/StoreKit2/StoreKit2Translators.swift

@@ -192,7 +192,7 @@ extension Product.PurchaseResult {
 
 @available(iOS 15.0, macOS 12.0, *)
 extension Transaction {
-  func convertToPigeon(receipt: String?) -> SK2TransactionMessage {
+  func convertToPigeon(receipt: String?, restoring: Bool = false) -> SK2TransactionMessage {
 
     let dateFormatter = DateFormatter()
     dateFormatter.dateFormat = "yyyy-MM-dd HH:mm:ss"
@@ -205,7 +205,7 @@ extension Transaction {
       expirationDate: expirationDate.map { dateFormatter.string(from: $0) },
       purchasedQuantity: Int64(purchasedQuantity),
       appAccountToken: appAccountToken?.uuidString,
-      restoring: receipt != nil,
+      restoring: restoring,
       receiptData: receipt,
       jsonRepresentation: String(decoding: jsonRepresentation, as: UTF8.self)
     )

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

@@ -8,10 +8,14 @@ import XCTest
 @testable import in_app_purchase_storekit
 
 final class FakeIAP2Callback: InAppPurchase2CallbackAPIProtocol {
+
+  public var lastUpdate: [in_app_purchase_storekit.SK2TransactionMessage] = []
+
   func onTransactionsUpdated(
     newTransactions newTransactionsArg: [in_app_purchase_storekit.SK2TransactionMessage],
     completion: @escaping (Result<Void, in_app_purchase_storekit.PigeonError>) -> Void
   ) {
+    lastUpdate = newTransactionsArg
     // We should only write to a flutter channel from the main thread.
     XCTAssertTrue(Thread.isMainThread)
   }
@@ -21,6 +25,7 @@ final class FakeIAP2Callback: InAppPurchase2CallbackAPIProtocol {
 final class InAppPurchase2PluginTests: XCTestCase {
   private var session: SKTestSession!
   private var plugin: InAppPurchasePlugin!
+  private var callback: FakeIAP2Callback = FakeIAP2Callback()
 
   override func setUp() async throws {
     try await super.setUp()
@@ -33,7 +38,7 @@ final class InAppPurchase2PluginTests: XCTestCase {
     plugin = InAppPurchasePluginStub(receiptManager: FIAPReceiptManagerStub()) { request in
       DefaultRequestHandler(requestHandler: FIAPRequestHandler(request: request))
     }
-    plugin.transactionCallbackAPI = FakeIAP2Callback()
+    plugin.transactionCallbackAPI = callback
     try plugin.startListeningToTransactions()
   }
 
@@ -86,11 +91,17 @@ final class InAppPurchase2PluginTests: XCTestCase {
 
     await fulfillment(of: [purchaseExpectation], timeout: 5)
 
+    XCTAssert(callback.lastUpdate.count == 1)
+    XCTAssert(
+      callback.lastUpdate.first?.restoring == false,
+      "Ordinary purchase updates should not be marked as restoring")
+
     plugin.transactions {
       result in
       switch result {
       case .success(let transactions):
         XCTAssert(transactions.count == 1)
+        XCTAssert(transactions.first?.restoring == false)
         transactionExpectation.fulfill()
       case .failure(let error):
         XCTFail("Getting transactions should NOT fail. Failed with \(error)")
@@ -376,6 +387,9 @@ final class InAppPurchase2PluginTests: XCTestCase {
     }
     await fulfillment(of: [purchaseExpectation], timeout: 5)
 
+    XCTAssert(callback.lastUpdate.count == 1)
+    XCTAssert(callback.lastUpdate.first?.restoring == false)
+
     plugin.restorePurchases { result in
       switch result {
       case .success():
@@ -385,6 +399,9 @@ final class InAppPurchase2PluginTests: XCTestCase {
       }
     }
     await fulfillment(of: [restoreExpectation], timeout: 5)
+
+    XCTAssert(callback.lastUpdate.count == 1)
+    XCTAssert(callback.lastUpdate.first?.restoring == true)
   }
 
   func testFinishTransaction() async throws {

packages/in_app_purchase/in_app_purchase_storekit/pubspec.yaml

@@ -2,7 +2,7 @@ name: in_app_purchase_storekit
 description: An implementation for the iOS and macOS platforms of the Flutter `in_app_purchase` plugin. This uses the StoreKit Framework.
 repository: https://github.com/flutter/packages/tree/main/packages/in_app_purchase/in_app_purchase_storekit
 issue_tracker: https://github.com/flutter/flutter/issues?q=is%3Aissue+is%3Aopen+label%3A%22p%3A+in_app_purchase%22
-version: 0.4.7
+version: 0.4.8
 
 environment:
   sdk: ^3.9.0

packages/in_app_purchase/in_app_purchase_storekit/test/in_app_purchase_storekit_2_platform_test.dart

@@ -120,6 +120,8 @@ void main() {
         final List<PurchaseDetails> result = await completer.future;
         expect(result.length, 1);
         expect(result.first.productID, dummyProductWrapper.id);
+        expect(result.first.status, PurchaseStatus.purchased);
+        expect(result.first.pendingCompletePurchase, true);
       },
     );