I just boxed up AppTransaction API. In the debug environment it appears to always return a VerificationResult that is .verified
Unlike Storekit1 calling AppTransaction.shared does not seem to cause a sandbox receipt to actually get written on the app bundle in Derived data. I was trying to purposefully mess with the receipt in order to get AppTransaction to fail so I can test how my app behaves when errors occur but there is no receipt to mess with. I tried using the old exit(173) API and it does cause a receipt to be fetched but that seems to be completely ignored by AppTransaction, it validates even if you trash or tamper with the receipt given by exit(173).
Is there a good way to test receipt validation failure using the high level Storekit2 API?