This is a major rewrite of the billing system. It moves subscription
information off of stripe Subscriptions and into a local CustomerPlan
table.
To keep this manageable, it leaves several things unimplemented
(downgrading, etc), and a variety of other TODOs in the code. There are also
some known regressions, e.g. error-handling on /upgrade is broken.
A lot of the seemingly unrelated test fixture changes are because we're
removing a query to stripe in the upgrade path, in cases when the user's
realm has an existing Customer object.
This used to be a more likely codepath, before we introduced
Customer.has_billing_relationship. It is no longer literally impossible to
hit this race condition, so I'm not deleting the code, but it's unlikely
enough that it's not worth figuring out how to test it.
Already better tested by the upgrade and downgrade tests using mock_stripe.
Note that the line that was removed is actually not possible to reach, since
canceled subscriptions aren't shown on the Customer object.
Also fixes a bug in process_initial_upgrade. If you have a card on file
(e.g. from a previous subscription), and try to upgrade by billing by
invoice, neither the if nor the elif condition applies.
There is no attribute called plan_interval. The reason
this was missed by mypy is moost likely due to us using
Any instead of Subscription in extract_current_subscription.
This will make it easier to mock the calls in our new stripe mocking
framework. I believe the two forms are equivalent, assuming the Stripe
Python bindings aren't doing anything crazy. And if not, well hopefully our
new testing framework will catch it :).
[Idea originally from Vishnu KS.]
Rishi Gupta
Vishnu Ks