Support multiple bodies

[dbanty]

It's possible for an endpoint to allow multiple content-types. In this case, the caller should select one at runtime, rather than one being picked arbitrarily.

This is a breaking change because instead of separate named params per type of body, there is only one body parameter (to better reflect that a choice is required).

Closes #822

[kgutwin]

Thanks! I think this approach makes a lot of sense. I actually ran into this problem just yesterday; my API has a method that accepts both application/json and multipart/form-data in the same endpoint, and I needed to do an ugly workaround to make it work.

One thought is that you could still support the old parameters with a signature like:

from typing import override

@override
def _get_kwargs(
    other_param: str,
    *,
    multipart_data: FormStyleBody,
) -> Dict[str, Any]:
    ...
@override
def _get_kwargs(
    other_param: str,
    *,
    json_body: JsonStyleBody,
) -> Dict[str, Any]:
    ...
@override
def _get_kwargs(
    other_param: str,
    *,
    body: Union[FormStyleBody, JsonStyleBody],
) -> Dict[str, Any]:
    ....

def _get_kwargs(
    other_param: str,
    *,
    multipart_data: Optional[FormStyleBody] = None,
    json_body: Optional[JsonStyleBody] = None,
    body: Optional[Union[FormStyleBody, JsonStyleBody]] = None,
) -> Dict[str, Any]:
    # code
    pass

This would allow the older parameters to be deprecated without needing to have it be a breaking change.

[codecov]

Codecov Report

Attention: 12 lines in your changes are missing coverage. Please review.

Comparison is base (f0cf8d2) 100.00% compared to head (15b2c5d) 99.38%.
Report is 4 commits behind head on main.

❗ Current head 15b2c5d differs from pull request most recent head f17b699. Consider uploading reports for the commit f17b699 to get more accurate results

Files	Patch %	Lines
openapi_python_client/parser/bodies.py	86.66%	8 Missing ⚠️
openapi_python_client/parser/openapi.py	81.81%	4 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff             @@
##              main     #900      +/-   ##
===========================================
- Coverage   100.00%   99.38%   -0.62%     
===========================================
  Files           49       50       +1     
  Lines         1940     1948       +8     
===========================================
- Hits          1940     1936       -4     
- Misses           0       12      +12     

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[dbanty]

This would allow the older parameters to be deprecated without needing to have it be a breaking change.

I'd also have to keep the old class names, which were inconsistent. Or generate two copies of the classes. Maybe if the deprecation story in Python was better (i.e., provided in-IDE help or could give a warning through type checkers) it'd feel more worth it, but I'm not sure it's worth the hassle.

I'm going to bundle this with OpenAPI 3.1 support I think which will make for a big "use care when updating" release anyway, since things could start breaking in unexpected ways.