Add test for BillingClientManager alternative billing only

packages/in_app_purchase/in_app_purchase_android/android/build.gradle

@@ -66,6 +66,6 @@ dependencies {
     testImplementation 'junit:junit:4.13.2'
     testImplementation 'org.json:json:20231013'
     testImplementation 'org.mockito:mockito-core:5.4.0'
-    androidTestImplementation 'androidx.test:runner:1.4.0'
+    androidTestImplementation 'androidx.test:runner:1.5.2'
     androidTestImplementation 'androidx.test.espresso:espresso-core:3.5.1'
 }

packages/in_app_purchase/in_app_purchase_android/lib/src/billing_client_wrappers/billing_client_manager.dart

@@ -36,8 +36,7 @@ class BillingClientManager {
   ///
   /// Callers need to check if AlternativeBillingOnly is available by calling
   /// [BillingClientWrapper.isAlternativeBillingOnlyAvailable] first.
-  BillingClientManager({bool enableAlternativeBillingOnly = false})
-      : _enableAlternativeBillingOnly = enableAlternativeBillingOnly {
+  BillingClientManager() : _enableAlternativeBillingOnly = false {
     _connect();
   }
 
@@ -58,7 +57,7 @@ class BillingClientManager {
   final StreamController<PurchasesResultWrapper> _purchasesUpdatedController =
       StreamController<PurchasesResultWrapper>.broadcast();
 
-  final bool _enableAlternativeBillingOnly;
+  bool _enableAlternativeBillingOnly;
   bool _isConnecting = false;
   bool _isDisposed = false;
 
@@ -125,6 +124,14 @@ class BillingClientManager {
     _purchasesUpdatedController.close();
   }
 
+  /// Ends connection to [BillingClient] and reconnects with [alternativeBillingState].
+  Future<void> reconnectWithAlternativeBillingOnlyState(
+      bool alternativeBillingOnlyState) async {
+    _enableAlternativeBillingOnly = alternativeBillingOnlyState;
+    // Ends connection and triggers OnBillingServiceDisconnected, which causes reconnect;
+    await client.endConnection();
+  }
+
   // If disposed, does nothing.
   // If currently connecting, waits for it to complete.
   // Otherwise, starts a new connection.

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

@@ -179,4 +179,17 @@ class InAppPurchaseAndroidPlatformAddition
             client.showAlternativeBillingOnlyInformationDialog());
     return wrapper;
   }
+
+  /// Disconnects, Sets AlternativeBillingOnly to true, and recoonects to
+  /// the [BillingClient].
+  ///
+  /// [alternativeBillingOnlyState] true will enable alternative billing only.
+  ///
+  /// Play apis have requirements for when this method can be called.
+  /// See: https://developer.android.com/google/play/billing/alternative/alternative-billing-without-user-choice-in-app
+  Future<void> setAlternativeBillingOnlyState(
+      bool alternativeBillingOnlyState) {
+    return _billingClientManager
+        .reconnectWithAlternativeBillingOnlyState(alternativeBillingOnlyState);
+  }
 }

packages/in_app_purchase/in_app_purchase_android/test/billing_client_wrappers/billing_client_manager_test.dart

@@ -81,6 +81,35 @@ void main() {
       expect(stubPlatform.countPreviousCalls(startConnectionCall), equals(2));
     });
 
+    test('re-connects when host calls reconnectWithAlternativeBillingOnlyState',
+        () async {
+      connectedCompleter.complete();
+      // Ensures all asynchronous connected code finishes.
+      await manager.runWithClientNonRetryable((_) async {});
+
+      await manager.reconnectWithAlternativeBillingOnlyState(true);
+      // Verify that connection was ended.
+      expect(stubPlatform.countPreviousCalls(endConnectionCall), equals(1));
+
+      stubPlatform.reset();
+
+      late Map<Object?, Object?> arguments;
+      stubPlatform.addResponse(
+        name: startConnectionCall,
+        additionalStepBeforeReturn: (dynamic value) =>
+            arguments = value as Map<dynamic, dynamic>,
+      );
+
+      /// Fake the disconnect that we would expect from a endConnectionCall.
+      await manager.client.callHandler(
+        const MethodCall(onBillingServiceDisconnectedCallback,
+            <String, dynamic>{'handle': 0}),
+      );
+      // Verify that after connection ended reconnect was called.
+      expect(stubPlatform.countPreviousCalls(startConnectionCall), equals(1));
+      expect(arguments['enableAlternativeBillingOnly'], isTrue);
+    });
+
     test(
       're-connects when operation returns BillingResponse.serviceDisconnected',
       () async {