Json requestBody cannot be optional

[orelmaliach]

Describe the bug
Generating an endpoint from an operation where requestBody has required: false (or required is unspecified) and an application/json content, still requires a body, despite it being optional.
Providing a None body with ...sync_detailed(body=None) will result in nil dereference in _kwargs["json"] = body.to_dict().
Providing an 'empty' body such as ...sync_detailed(body=RequestBody()) will result in an empty json object. i.e. {}, which is not desirable.

OpenAPI Spec File

openapi: 3.1.1
info:
  title: ""
  version: ""
paths:
  /request:
    post:
      operationId: request
      requestBody:
        required: false
        content:
          application/json:
            schema:
              type: object
      responses:
        "201":
          description: ""

Desktop (please complete the following information):

• OS: macOS 15.7.1
• Python version: 3.13.3
• openapi-python-client version: 0.25.1

Additional context
I've described the bug for application/json request bodies, but it may exist for other content types as well.
Similarly, I provided an example using openAPI spec version 3.1.1, but it might be relevant for other versions as well.

[dbanty]

If the body is not required, that enables you to omit the parameter entirely, like sync_detailed().

Passing any value there will try to set that value as the body. None becomes null, classes become objects, etc.

The client also has a special UNSET value it uses as a sentinel to determine when a value hasn't been passed. If you need to, you can import that from types.py and pass it like sync_detailed(body=UNSET).

The preference, though, is to not pass a value at all if it's not required and you don't need it.

[orelmaliach]

Not passing any value results of course in TypeError: sync_detailed() missing 1 required positional argument: 'body'.
And Unset fails when to_dict() is invoked on it in _get_kwargs.
I generated a test client with above yaml. No custom config/templates, and result is same.

(venv) ➜ cat request.py | grep -A5 sync_detailed
def sync_detailed(
    *,
    client: Union[AuthenticatedClient, Client],
    body: RequestBody,
) -> Response[Any]:
    """

Am I missing something?!

[dbanty]

Am I missing something?!

Nope, you're right! The thing that works for every other type of input doesn't work for bodies 😱.

[dbanty]

I whipped up a potential fix in #1357, please give it a try and let me know if it works!

Sorry for accidentally gaslighting you 😅

[orelmaliach]

Your quick responses and resolution more than make up for it :)
A quick test from my side looks good for both application/json and application/x-www-form-urlencoded content types!