[in_app_purchase_android] GooglePlayPurchaseParam add possibility set selected offerToken (#8452)

Option to add purchase parameters in GooglePlayPurchaseParam to set selected offer token. In subscribtion with multiple offer in base plan, the user can choose which offer to want buy and then this selected offer token is sent to the billing flow

flutter/flutter#150348

Author: rmasarovic

packages/in_app_purchase/in_app_purchase_android/CHANGELOG.md

@@ -1,3 +1,7 @@
+## 0.4.0+2
+
+* Adds support for setting the `offerToken` on `GooglePlayPurchaseParam`.
+
 ## 0.4.0+1
 
 * Updates compileSdk 34 to flutter.compileSdkVersion.

packages/in_app_purchase/in_app_purchase_android/lib/src/in_app_purchase_android_platform.dart

@@ -142,13 +142,15 @@ class InAppPurchaseAndroidPlatform extends InAppPurchasePlatform {
   @override
   Future<bool> buyNonConsumable({required PurchaseParam purchaseParam}) async {
     ChangeSubscriptionParam? changeSubscriptionParam;
+    String? offerToken;
 
     if (purchaseParam is GooglePlayPurchaseParam) {
       changeSubscriptionParam = purchaseParam.changeSubscriptionParam;
+      offerToken = purchaseParam.offerToken;
     }
 
-    String? offerToken;
-    if (purchaseParam.productDetails is GooglePlayProductDetails) {
+    if (offerToken == null &&
+        purchaseParam.productDetails is GooglePlayProductDetails) {
       offerToken =
           (purchaseParam.productDetails as GooglePlayProductDetails).offerToken;
     }

packages/in_app_purchase/in_app_purchase_android/lib/src/types/google_play_purchase_param.dart

@@ -13,9 +13,16 @@ class GooglePlayPurchaseParam extends PurchaseParam {
     required super.productDetails,
     super.applicationUserName,
     this.changeSubscriptionParam,
+    this.offerToken,
   });
 
   /// The 'changeSubscriptionParam' containing information for upgrading or
   /// downgrading an existing subscription.
   final ChangeSubscriptionParam? changeSubscriptionParam;
+
+  /// For One-time product, "offerToken" shouldn't be filled.
+  ///
+  /// For subscriptions, to get the offer token corresponding to the selected
+  /// offer call productDetails.subscriptionOfferDetails?.get(selectedOfferIndex)?.offerToken
+  final String? offerToken;
 }

packages/in_app_purchase/in_app_purchase_android/pubspec.yaml

@@ -2,7 +2,8 @@ name: in_app_purchase_android
 description: An implementation for the Android platform of the Flutter `in_app_purchase` plugin. This uses the Android BillingClient APIs.
 repository: https://github.com/flutter/packages/tree/main/packages/in_app_purchase/in_app_purchase_android
 issue_tracker: https://github.com/flutter/flutter/issues?q=is%3Aissue+is%3Aopen+label%3A%22p%3A+in_app_purchase%22
-version: 0.4.0+1
+
+version: 0.4.0+2
 
 environment:
   sdk: ^3.6.0

packages/in_app_purchase/in_app_purchase_android/test/in_app_purchase_android_platform_test.dart

@@ -20,6 +20,33 @@ import 'billing_client_wrappers/product_details_wrapper_test.dart';
 import 'billing_client_wrappers/purchase_wrapper_test.dart';
 import 'test_conversion_utils.dart';
 
+const ProductDetailsWrapper dummySubscriptionProductDetails =
+    ProductDetailsWrapper(
+  description: 'description',
+  name: 'name',
+  productId: 'productId',
+  productType: ProductType.subs,
+  title: 'title',
+  subscriptionOfferDetails: <SubscriptionOfferDetailsWrapper>[
+    SubscriptionOfferDetailsWrapper(
+      basePlanId: 'basePlanId',
+      offerTags: <String>['offerTags'],
+      offerId: 'offerId',
+      offerIdToken: 'offerToken',
+      pricingPhases: <PricingPhaseWrapper>[
+        PricingPhaseWrapper(
+          billingCycleCount: 4,
+          billingPeriod: 'billingPeriod',
+          formattedPrice: r'$100',
+          priceAmountMicros: 100000000,
+          priceCurrencyCode: 'USD',
+          recurrenceMode: RecurrenceMode.finiteRecurring,
+        ),
+      ],
+    ),
+  ],
+);
+
 void main() {
   TestWidgetsFlutterBinding.ensureInitialized();
 
@@ -255,6 +282,67 @@ void main() {
   });
 
   group('make payment', () {
+    test('buy non consumable subscribe offer, serializes and deserializes data',
+        () async {
+      const ProductDetailsWrapper productDetails =
+          dummySubscriptionProductDetails;
+      const String accountId = 'hashedAccountId';
+      const String debugMessage = 'dummy message';
+      const BillingResponse sentCode = BillingResponse.ok;
+      const BillingResultWrapper expectedBillingResult = BillingResultWrapper(
+          responseCode: sentCode, debugMessage: debugMessage);
+
+      when(mockApi.launchBillingFlow(any)).thenAnswer((_) async {
+        // Mock java update purchase callback.
+        iapAndroidPlatform.billingClientManager.client.hostCallbackHandler
+            .onPurchasesUpdated(PlatformPurchasesResponse(
+          billingResult: convertToPigeonResult(expectedBillingResult),
+          purchases: <PlatformPurchase>[
+            PlatformPurchase(
+              orderId: 'orderID1',
+              products: <String>[productDetails.productId],
+              isAutoRenewing: false,
+              packageName: 'package',
+              purchaseTime: 1231231231,
+              purchaseToken: 'token',
+              signature: 'sign',
+              originalJson: 'json',
+              developerPayload: 'dummy payload',
+              isAcknowledged: true,
+              purchaseState: PlatformPurchaseState.purchased,
+              quantity: 1,
+            )
+          ],
+        ));
+
+        return convertToPigeonResult(expectedBillingResult);
+      });
+      final Completer<PurchaseDetails> completer = Completer<PurchaseDetails>();
+      PurchaseDetails purchaseDetails;
+      final Stream<List<PurchaseDetails>> purchaseStream =
+          iapAndroidPlatform.purchaseStream;
+      late StreamSubscription<List<PurchaseDetails>> subscription;
+      subscription = purchaseStream.listen((List<PurchaseDetails> details) {
+        purchaseDetails = details.first;
+        completer.complete(purchaseDetails);
+        subscription.cancel();
+      }, onDone: () {});
+      final GooglePlayPurchaseParam purchaseParam = GooglePlayPurchaseParam(
+          offerToken:
+              productDetails.subscriptionOfferDetails?.first.offerIdToken,
+          productDetails:
+              GooglePlayProductDetails.fromProductDetails(productDetails).first,
+          applicationUserName: accountId);
+      final bool launchResult = await iapAndroidPlatform.buyNonConsumable(
+          purchaseParam: purchaseParam);
+
+      final PurchaseDetails result = await completer.future;
+      expect(launchResult, isTrue);
+      expect(result.purchaseID, 'orderID1');
+      expect(result.status, PurchaseStatus.purchased);
+      expect(result.productID, productDetails.productId);
+    });
+
     test('buy non consumable, serializes and deserializes data', () async {
       const ProductDetailsWrapper productDetails = dummyOneTimeProductDetails;
       const String accountId = 'hashedAccountId';