According to Google's documentation, orderId field of the INAPP_PURCHASE_DATA should be formatted in a way that you can figure out an recurrence number from it.
"GPA.1234-5678-9012-34567" (base order number)
"GPA.1234-5678-9012-34567..0" (first recurrence orderID)
"GPA.1234-5678-9012-34567..1" (second recurrence orderID)
"GPA.1234-5678-9012-34567..2" (third recurrence orderID)
When it comes to free trials, things get unclear. I would expect the behaviour to follow the same pattern:
- user starts a trial, orderId will be base order number
- trial ends and user is charged for the first time, orderId will indicate first recurrence
As test purchases don't include orderId, the only way to test this is to start a real trial and check results in (minimum) seven days. Can therefore anyone confirm this?
Further on, let's say user cancels trial immediately and starts a subscription right after that? Google will make sure user gets charged and all, but will orderId be a base order again or next recurrence?