[FLAPI-2083] Fix various models type hints when maybe parsing

[jesse-c]

Fix Order model type hints

By (possibly) setting the value varaible to a non-iterable type, we get warnings. Instead, explicitly continue on once we maybe parse a str type. We wouldn't want to iterate over a str.

We don't serialise Payments for Orders so I've removed them from the appropriate fixtures.

TODO

• Rebase fixup commits
• Fix complexity warnings

[sgerrand]

LGTM. 👍

[sgerrand]

🤔

[sgerrand]

Some of these changes have broken the implementation – check the integration tests in examples/ for pointers to where.

[jesse-c]

@sgerrand: I'll go through them today.

[sgerrand]

Thanks Jesse!

[sgerrand]

I'm pointing out the obvious but tox -e linting is unhappy.

  ./duffel_api/models/order.py:20:5: C901 'Order.__init__' is too complex (12)
16
      def __init__(self, json):
17
      ^
18
  ./duffel_api/models/offer.py:23:5: C901 'Offer.__init__' is too complex (12)
19
      def __init__(self, json):
20
      ^

[jesse-c]

Yup, I'm working on those atm. I've got them recorded in the TODO list in the description. Thanks for making sure it's not missed though!

I think I've found some pre-existing bugs through refactoring this. 😬

[sgerrand]

Nice – that's good thing!

[jesse-c]

@sgerrand: This is ready for review now.

[sgerrand]

LGTM. 👍