Flask restx multipart/form request with file and body with swagger - python-3.x

Question

I am trying to implement, using flask-restx, an endpoint which will take both formData (a list of files to be more precise) and a body as json. My code looks as follow:
Multiple files param in some module:
def authorization_param(ns: Namespace, parser: Optional[RequestParser] = None) -> RequestParser:
if not parser:
parser = ns.parser()
parser.add_argument('Authorization', location='headers', required=False, default='Bearer ')
return parser
def multiple_file_param(arg_name: str, ns: Namespace, parser: Optional[RequestParser] = None) -> RequestParser:
if not parser:
parser = ns.parser()
parser.add_argument(arg_name, type=FileStorage, location='files', required=True, action='append')
return parser
Model:
some_form_model = api.model('form', {'field': fields.String())
And the endpoint itself:
ns = Namespace('sth', description='Some stuff'))
auth_param = authorization_param(ns=ns)
file_param = multiple_file_param(arg_name='File', ns=ns)
#ns.route('/files')
#ns.expect(auth_param)
class PreprocessFiles(Resource):
#ns.response(code=201, description='Job created', model=some_model)
#ns.response(code=400, description='Bad request', model=None)
#ns.response(code=401, description='Authentication Error', model=None)
#ns.response(code=403, description='Forbidden', model=None)
#ns.response(
code=422,
description='Input data validation Error',
model=some_model
)
#ns.expect(some_form_model)
#ns.expect(file_param)
def post(self):
payload = request.get_json()
# do some stuff..
return {'text': 'ok'}, 201
The endpoint is registered in an API object:
api.add_namespace(ns)
My problem is that in swagger I get either input body or file parameter, depending on the order of decorators I use. If I try to pass both form model and file param into one ns.expect as so
#ns.expect(some_form_model, file_param)
I get the following error in the console and the schema is not rendered:
2022-08-26 12:19:45.764 ERROR flask_restx.api api.__schema__: Unable to render schema
Traceback (most recent call last):
File "D:\Project\venv\lib\site-packages\flask_restx\api.py", line 571, in __schema__
self._schema = Swagger(self).as_dict()
File "D:\Project\venv\lib\site-packages\flask_restx\swagger.py", line 239, in as_dict
serialized = self.serialize_resource(
File "D:\Project\venv\lib\site-packages\flask_restx\swagger.py", line 446, in serialize_resource
path[method] = self.serialize_operation(doc, method)
File "D:\Project\venv\lib\site-packages\flask_restx\swagger.py", line 469, in serialize_operation
if any(p["type"] == "file" for p in all_params):
File "D:\Project\venv\lib\site-packages\flask_restx\swagger.py", line 469, in <genexpr>
if any(p["type"] == "file" for p in all_params):
KeyError: 'type'
Is there any way to go around this? I would really like to have good swagger docs for the frontend folks.
Thanks in advance!
Best,
Mateusz