[Alokxyz1112]

The docs for completePurchase (in both in_app_purchase and in_app_purchase_platform_interface) say it throws a PurchaseException with an errorCode, but that type doesn't exist anywhere in the plugin. This replaces that paragraph with what the implementations actually do:

• Android (InAppPurchaseAndroidPlatform.completePurchase) returns a BillingResultWrapper, so a failed acknowledge shows up in its responseCode.
• iOS/macOS (InAppPurchaseStoreKitPlatform.completePurchase) calls finishTransaction / SK2Transaction.finish over Pigeon, which throws a PlatformException on error.

Added a line under ## NEXT in both CHANGELOGs since this is a doc only change.

Fixes flutter/flutter#118626

Pre-Review Checklist

• I read the Contributor Guide and followed the process outlined there for submitting PRs.
• I read the AI contribution guidelines and understand my responsibilities, or I am not using AI tools.
• I read the Tree Hygiene page, which explains my responsibilities.
• I read and followed the relevant style guides and ran the auto-formatter.
• I signed the CLA.
• The title of the PR starts with the name of the package surrounded by square brackets, e.g. [shared_preferences]
• I linked to at least one issue that this PR fixes in the description above.
• I followed the version and CHANGELOG instructions, using semantic versioning and the repository CHANGELOG style, or I have commented below to indicate which documented exception this PR falls under¹.
• I updated/added any relevant documentation (doc comments with ///).
• I added new tests to check the change I am making, or I have commented below to indicate which test exemption this PR falls under¹.
• All existing and new tests are passing.

Version: doc comment only change, so no version bump, just a ## NEXT entry.
Tests: exempt, this only changes doc comments.

Footnotes

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. ↩ ↩²

[gemini-code-assist]

Code Review

This pull request updates the documentation for completePurchase in both in_app_purchase and in_app_purchase_platform_interface to remove references to the non-existent PurchaseException and explain platform-specific error handling. The review feedback suggests clarifying that because completePurchase returns Future<void> in the unified API, Android failures are silent and the BillingResultWrapper is only accessible when using the platform-specific implementation directly.

[gemini-code-assist]

Since InAppPurchase.completePurchase returns Future<void>, the returned future for the unified API does not actually complete with a BillingResultWrapper for the caller to inspect. This is only true if they are using the platform-specific InAppPurchaseAndroidPlatform directly. For the unified API, failures on Android are silent (the future completes without throwing). Let's clarify this in the documentation to avoid confusing developers who might expect to be able to access the BillingResultWrapper or its responseCode from the returned Future<void>.

  /// There is no shared exception type for a failed [completePurchase] call, so
  /// errors are platform specific. On Android, the underlying platform implementation
  /// returns a `BillingResultWrapper` (accessible when using `InAppPurchaseAndroidPlatform`
  /// directly), but when using this unified `InAppPurchase` API, the returned `Future<void>`
  /// completes without throwing an exception. On iOS and macOS, a failure reported
  /// by StoreKit is thrown as a `PlatformException`.

[gemini-code-assist]

Since InAppPurchasePlatform.completePurchase returns Future<void>, the returned future for the unified API does not actually complete with a BillingResultWrapper for the caller to inspect. This is only true if they are using the platform-specific InAppPurchaseAndroidPlatform directly. For the unified API, failures on Android are silent (the future completes without throwing). Let's clarify this in the documentation to avoid confusing developers who might expect to be able to access the BillingResultWrapper or its responseCode from the returned Future<void>.

  /// There is no shared exception type for a failed [completePurchase] call, so
  /// errors are platform specific. On Android, the underlying platform implementation
  /// returns a `BillingResultWrapper` (accessible when using `InAppPurchaseAndroidPlatform`
  /// directly), but when using this unified `InAppPurchasePlatform` API, the returned
  /// `Future<void>` completes without throwing an exception. On iOS and macOS, a
  /// failure reported by StoreKit is thrown as a `PlatformException`.