Duplicate payments were showing up in the discourse ui for users. Actual
transactions in stripe were not being duplicated. This fix ensures that
when parsing the api response we don't append any duplicates. Added a
duplicate entry to the specs to test for this.
I do think there can be some improvements made to this controller
endpoint, but I'd like to save those for a different and larger PR and
just get this fix out first.
The code in the plugin needed a dramatic cleanup. This refactor collapses the Plan/Product/Subscription controllers on the backend into one new controller: `SubscribeController`.
This reduces N+1 calls to the back end during the subscription process and simplifies use of the code.
I've also removed a bunch of dead code and refactored some logic into methods for easier readability. No feature/functionality changes in this commit; only refactoring. However, refactoring will allow for implementation of better anonymous user handling, so this is largely a foundation to enable making that change.
Building off the foundation of using the Prices API, this PR adds the ability to create a one-time purchase plan for any product, which then can add a user to the specified plan group.
Some things to be aware of:
One-time purchases cannot have trials.
One-time purchases use the Invoice API instead of Subscriptions. Invoices are created then charged immediately.
Users should receive emails for these invoices directly from Stripe just like subscriptions.