[in_app_purchase] migrate playing billing library to v3

packages/in_app_purchase/CHANGELOG.md

@@ -2,10 +2,14 @@
 
 * Migrate to Google Billing Library 3.0
   * Add `obfuscatedProfileId`, `purchaseToken` in [BillingClientWrapper.launchBillingFlow].
-  * Removed `developerPayload` in [BillingClientWrapper.acknowledgePurchase], [BillingClientWrapper.consumeAsync], [InAppPurchaseConnection.completePurchase], [InAppPurchaseConnection.consumePurchase].
   * **Breaking Change**
+    * Removed `developerPayload` in [BillingClientWrapper.acknowledgePurchase], [BillingClientWrapper.consumeAsync], [InAppPurchaseConnection.completePurchase], [InAppPurchaseConnection.consumePurchase].
     * Removed `isRewarded` from [SkuDetailsWrapper].
     * [SkuDetailsWrapper.introductoryPriceCycles] now returns `int` instead of `String`.
+    * Above breaking changes are inline with the breaking changes introduced in [Google Play Billing 3.0 release](https://developer.android.com/google/play/billing/release-notes#3-0).
+    * Additional information on some the changes:
+      * [Dropping reward SKU support](https://support.google.com/googleplay/android-developer/answer/9155268?hl=en)
+      * [Developer payload](https://developer.android.com/google/play/billing/developer-payload)
 
 ## 0.4.1
 

packages/in_app_purchase/example/android/app/src/test/java/io/flutter/plugins/inapppurchase/MethodCallHandlerTest.java

@@ -263,8 +263,11 @@ public void querySkuDetailsAsync_clientDisconnected() {
     verify(result, never()).success(any());
   }
 
+  // Test launchBillingFlow not crash if `accountId` is `null`
+  // Ideally, we should check if the `accountId` is null in the parameter; however,
+  // since PBL 3.0, the `accountId` variable is not public.
   @Test
-  public void launchBillingFlow_ok_null_AccountId() {
+  public void launchBillingFlow_null_AccountId_do_not_crash() {
     // Fetch the sku details first and then prepare the launch billing flow call
     String skuId = "foo";
     queryForSkus(singletonList(skuId));

packages/in_app_purchase/lib/src/billing_client_wrappers/billing_client_wrapper.dart

@@ -155,11 +155,11 @@ class BillingClient {
   /// The [skuDetails] needs to have already been fetched in a [querySkuDetails]
   /// call. The [accountId] is an optional hashed string associated with the user
   /// that's unique to your app. It's used by Google to detect unusual behavior.
-  /// Do not pass in a cleartext [accountId], Do not use this field to store any Personally Identifiable Information (PII)
+  /// Do not pass in a cleartext [accountId], and do not use this field to store any Personally Identifiable Information (PII)
   /// such as emails in cleartext. Attempting to store PII in this field will result in purchases being blocked.
   /// Google Play recommends that you use either encryption or a one-way hash to generate an obfuscated identifier to send to Google Play.
   ///
-  /// Specifies an optional [obfuscatedProfileId]  that is uniquely associated with the user's profile in your app.
+  /// Specifies an optional [obfuscatedProfileId] that is uniquely associated with the user's profile in your app.
   /// Some applications allow users to have multiple profiles within a single account. Use this method to send the user's profile identifier to Google.
   /// Setting this field requests the user's obfuscated account id.
   ///
@@ -174,10 +174,8 @@ class BillingClient {
   /// [`BillingClient#launchBillingFlow`](https://developer.android.com/reference/com/android/billingclient/api/BillingClient#launchbillingflow).
   /// It constructs a
   /// [`BillingFlowParams`](https://developer.android.com/reference/com/android/billingclient/api/BillingFlowParams)
-  /// instance by [setting the given
-  /// skuDetails](https://developer.android.com/reference/com/android/billingclient/api/BillingFlowParams.Builder.html#setskudetails)
-  /// , [the given
-  /// accountId](https://developer.android.com/reference/com/android/billingclient/api/BillingFlowParams.Builder#setObfuscatedAccountId(java.lang.String))
+  /// instance by [setting the given skuDetails](https://developer.android.com/reference/com/android/billingclient/api/BillingFlowParams.Builder.html#setskudetails),
+  /// [the given accountId](https://developer.android.com/reference/com/android/billingclient/api/BillingFlowParams.Builder#setObfuscatedAccountId(java.lang.String))
   /// and the [obfuscatedProfileId] (https://developer.android.com/reference/com/android/billingclient/api/BillingFlowParams.Builder#setobfuscatedprofileid).
   ///
   /// When this method is called to purchase a subscription, an optional `oldSku`
@@ -195,6 +193,8 @@ class BillingClient {
       String? purchaseToken,
       ProrationMode? prorationMode}) async {
     assert(sku != null);
+    assert((oldSku == null) == (purchaseToken == null),
+        'oldSku and purchaseToken should have the same nullability');
     final Map<String, dynamic> arguments = <String, dynamic>{
       'sku': sku,
       'accountId': accountId,

packages/in_app_purchase/lib/src/billing_client_wrappers/purchase_wrapper.dart

@@ -121,7 +121,7 @@ class PurchaseWrapper {
   ///
   /// The value is `null` if it wasn't specified when the purchase was acknowledged or consumed.
   /// The `developerPayload` is removed from [BillingClientWrapper.acknowledgePurchase], [BillingClientWrapper.consumeAsync], [InAppPurchaseConnection.completePurchase], [InAppPurchaseConnection.consumePurchase]
-  /// after plugin version `0.5.0`. As a result, this will be `null` for new purchases happened after `0.5.0`.
+  /// after plugin version `0.5.0`. As a result, this will be `null` for new purchases that happen after updating to `0.5.0`.
   final String? developerPayload;
 
   /// Whether the purchase has been acknowledged.

packages/in_app_purchase/lib/src/billing_client_wrappers/sku_details_wrapper.dart

@@ -72,8 +72,7 @@ class SkuDetailsWrapper {
 
   /// The number of subscription billing periods for which the user will be given the introductory price, such as 3.
   /// Returns 0 if the SKU is not a subscription or doesn't have an introductory period.
-  /// Returns -1 if the value is not available.
-  @JsonKey(defaultValue: -1)
+  @JsonKey(defaultValue: 0)
   final int introductoryPriceCycles;
 
   /// The billing period of [introductoryPrice], in ISO 8601 format.

packages/in_app_purchase/test/billing_client_wrappers/billing_client_wrapper_test.dart

@@ -211,6 +211,40 @@ void main() {
       expect(arguments['obfuscatedProfileId'], equals(profileId));
     });
 
+    test(
+        'Change subscription throws assertion error `oldSku` and `purchaseToken` has different nullability',
+        () async {
+      const String debugMessage = 'dummy message';
+      final BillingResponse responseCode = BillingResponse.ok;
+      final BillingResultWrapper expectedBillingResult = BillingResultWrapper(
+          responseCode: responseCode, debugMessage: debugMessage);
+      stubPlatform.addResponse(
+        name: launchMethodName,
+        value: buildBillingResultMap(expectedBillingResult),
+      );
+      final SkuDetailsWrapper skuDetails = dummySkuDetails;
+      final String accountId = 'hashedAccountId';
+      final String profileId = 'hashedProfileId';
+
+      expect(
+          billingClient.launchBillingFlow(
+              sku: skuDetails.sku,
+              accountId: accountId,
+              obfuscatedProfileId: profileId,
+              oldSku: dummyOldPurchase.sku,
+              purchaseToken: null),
+          throwsAssertionError);
+
+      expect(
+          billingClient.launchBillingFlow(
+              sku: skuDetails.sku,
+              accountId: accountId,
+              obfuscatedProfileId: profileId,
+              oldSku: null,
+              purchaseToken: dummyOldPurchase.purchaseToken),
+          throwsAssertionError);
+    });
+
     test(
         'serializes and deserializes data on change subscription without proration',
         () async {
@@ -225,22 +259,22 @@ void main() {
       final SkuDetailsWrapper skuDetails = dummySkuDetails;
       final String accountId = 'hashedAccountId';
       final String profileId = 'hashedProfileId';
-      final String purchaseToken = 'aPurchaseToken';
 
       expect(
           await billingClient.launchBillingFlow(
               sku: skuDetails.sku,
               accountId: accountId,
               obfuscatedProfileId: profileId,
               oldSku: dummyOldPurchase.sku,
-              purchaseToken: purchaseToken),
+              purchaseToken: dummyOldPurchase.purchaseToken),
           equals(expectedBillingResult));
       Map<dynamic, dynamic> arguments =
           stubPlatform.previousCallMatching(launchMethodName).arguments;
       expect(arguments['sku'], equals(skuDetails.sku));
       expect(arguments['accountId'], equals(accountId));
       expect(arguments['oldSku'], equals(dummyOldPurchase.sku));
-      expect(arguments['purchaseToken'], equals(purchaseToken));
+      expect(
+          arguments['purchaseToken'], equals(dummyOldPurchase.purchaseToken));
       expect(arguments['obfuscatedProfileId'], equals(profileId));
     });
 
@@ -258,7 +292,6 @@ void main() {
       final SkuDetailsWrapper skuDetails = dummySkuDetails;
       final String accountId = 'hashedAccountId';
       final String profileId = 'hashedProfileId';
-      final String purchaseToken = 'aPurchaseToken';
       final prorationMode = ProrationMode.immediateAndChargeProratedPrice;
 
       expect(
@@ -268,15 +301,16 @@ void main() {
               obfuscatedProfileId: profileId,
               oldSku: dummyOldPurchase.sku,
               prorationMode: prorationMode,
-              purchaseToken: purchaseToken),
+              purchaseToken: dummyOldPurchase.purchaseToken),
           equals(expectedBillingResult));
       Map<dynamic, dynamic> arguments =
           stubPlatform.previousCallMatching(launchMethodName).arguments;
       expect(arguments['sku'], equals(skuDetails.sku));
       expect(arguments['accountId'], equals(accountId));
       expect(arguments['oldSku'], equals(dummyOldPurchase.sku));
       expect(arguments['obfuscatedProfileId'], equals(profileId));
-      expect(arguments['purchaseToken'], equals(purchaseToken));
+      expect(
+          arguments['purchaseToken'], equals(dummyOldPurchase.purchaseToken));
       expect(arguments['prorationMode'],
           ProrationModeConverter().toJson(prorationMode));
     });