fix(python,asyncio): multipart form data serialization (#19302)

* fix: object serialization for multipart requests

This PR is essentially
<https://github.com/OpenAPITools/openapi-generator/pull/18140> but for
the asyncio client.

* fix: int serialization for multipart requests

urllib3 handles serializing ints in post params (ref 1), while asyncio
explicitly does not (ref 2).

ref 1: <9316764e90/src/urllib3/filepost.py (L75-L76)>
ref 2: <https://github.com/aio-libs/aiohttp/issues/920>

* test: new fake multipart endpoint with files and body

* test: regression test for stringified body params

* fix: mypy tweak

* fix: FILES regeneration

* feat: object, int serialization for multipart reqs

Extends previous commits (and #18140) to cover the python-pydantic-v1
client as well.

* fix: use async with in test

* test: regression test for pydantic-v1-aiohttp

* test: add regression test to pydantic-v1

Also brings the second test in line with the first, patching
`urllib3.PoolManager.urlopen`

samples/openapi3/client/petstore/python-aiohttp/.openapi-generator/FILES

@@ -112,6 +112,7 @@ docs/TestObjectForMultipartRequestsRequestMarker.md
 docs/Tiger.md
 docs/UnnamedDictWithAdditionalModelListProperties.md
 docs/UnnamedDictWithAdditionalStringListProperties.md
+docs/UploadFileWithAdditionalPropertiesRequestObject.md
 docs/User.md
 docs/UserApi.md
 docs/WithNestedOneOf.md
@@ -233,6 +234,7 @@ petstore_api/models/test_object_for_multipart_requests_request_marker.py
 petstore_api/models/tiger.py
 petstore_api/models/unnamed_dict_with_additional_model_list_properties.py
 petstore_api/models/unnamed_dict_with_additional_string_list_properties.py
+petstore_api/models/upload_file_with_additional_properties_request_object.py
 petstore_api/models/user.py
 petstore_api/models/with_nested_one_of.py
 petstore_api/py.typed

samples/openapi3/client/petstore/python-aiohttp/README.md

@@ -123,6 +123,7 @@ Class | Method | HTTP request | Description
 *FakeApi* | [**test_object_for_multipart_requests**](docs/FakeApi.md#test_object_for_multipart_requests) | **POST** /fake/object_for_multipart_requests | 
 *FakeApi* | [**test_query_parameter_collection_format**](docs/FakeApi.md#test_query_parameter_collection_format) | **PUT** /fake/test-query-parameters | 
 *FakeApi* | [**test_string_map_reference**](docs/FakeApi.md#test_string_map_reference) | **POST** /fake/stringMap-reference | test referenced string map
+*FakeApi* | [**upload_file_with_additional_properties**](docs/FakeApi.md#upload_file_with_additional_properties) | **POST** /fake/upload_file_with_additional_properties | uploads a file and additional properties using multipart/form-data
 *FakeClassnameTags123Api* | [**test_classname**](docs/FakeClassnameTags123Api.md#test_classname) | **PATCH** /fake_classname_test | To test class name in snake case
 *ImportTestDatetimeApi* | [**import_test_return_datetime**](docs/ImportTestDatetimeApi.md#import_test_return_datetime) | **GET** /import_test/return_datetime | test date time
 *PetApi* | [**add_pet**](docs/PetApi.md#add_pet) | **POST** /pet | Add a new pet to the store
@@ -252,6 +253,7 @@ Class | Method | HTTP request | Description
  - [Tiger](docs/Tiger.md)
  - [UnnamedDictWithAdditionalModelListProperties](docs/UnnamedDictWithAdditionalModelListProperties.md)
  - [UnnamedDictWithAdditionalStringListProperties](docs/UnnamedDictWithAdditionalStringListProperties.md)
+ - [UploadFileWithAdditionalPropertiesRequestObject](docs/UploadFileWithAdditionalPropertiesRequestObject.md)
  - [User](docs/User.md)
  - [WithNestedOneOf](docs/WithNestedOneOf.md)
 

samples/openapi3/client/petstore/python-aiohttp/docs/FakeApi.md

@@ -40,6 +40,7 @@ Method | HTTP request | Description
 [**test_object_for_multipart_requests**](FakeApi.md#test_object_for_multipart_requests) | **POST** /fake/object_for_multipart_requests | 
 [**test_query_parameter_collection_format**](FakeApi.md#test_query_parameter_collection_format) | **PUT** /fake/test-query-parameters | 
 [**test_string_map_reference**](FakeApi.md#test_string_map_reference) | **POST** /fake/stringMap-reference | test referenced string map
+[**upload_file_with_additional_properties**](FakeApi.md#upload_file_with_additional_properties) | **POST** /fake/upload_file_with_additional_properties | uploads a file and additional properties using multipart/form-data
 
 
 # **fake_any_type_request_body**
@@ -2482,3 +2483,76 @@ No authorization required
 
 [[Back to top]](#) [[Back to API list]](../README.md#documentation-for-api-endpoints) [[Back to Model list]](../README.md#documentation-for-models) [[Back to README]](../README.md)
 
+# **upload_file_with_additional_properties**
+> ModelApiResponse upload_file_with_additional_properties(file, object=object, count=count)
+
+uploads a file and additional properties using multipart/form-data
+
+
+
+### Example
+
+
+```python
+import petstore_api
+from petstore_api.models.model_api_response import ModelApiResponse
+from petstore_api.models.upload_file_with_additional_properties_request_object import UploadFileWithAdditionalPropertiesRequestObject
+from petstore_api.rest import ApiException
+from pprint import pprint
+
+# Defining the host is optional and defaults to http://petstore.swagger.io:80/v2
+# See configuration.py for a list of all supported configuration parameters.
+configuration = petstore_api.Configuration(
+    host = "http://petstore.swagger.io:80/v2"
+)
+
+
+# Enter a context with an instance of the API client
+async with petstore_api.ApiClient(configuration) as api_client:
+    # Create an instance of the API class
+    api_instance = petstore_api.FakeApi(api_client)
+    file = None # bytearray | file to upload
+    object = petstore_api.UploadFileWithAdditionalPropertiesRequestObject() # UploadFileWithAdditionalPropertiesRequestObject |  (optional)
+    count = 56 # int | Integer count (optional)
+
+    try:
+        # uploads a file and additional properties using multipart/form-data
+        api_response = await api_instance.upload_file_with_additional_properties(file, object=object, count=count)
+        print("The response of FakeApi->upload_file_with_additional_properties:\n")
+        pprint(api_response)
+    except Exception as e:
+        print("Exception when calling FakeApi->upload_file_with_additional_properties: %s\n" % e)
+```
+
+
+
+### Parameters
+
+
+Name | Type | Description  | Notes
+------------- | ------------- | ------------- | -------------
+ **file** | **bytearray**| file to upload | 
+ **object** | [**UploadFileWithAdditionalPropertiesRequestObject**](UploadFileWithAdditionalPropertiesRequestObject.md)|  | [optional] 
+ **count** | **int**| Integer count | [optional] 
+
+### Return type
+
+[**ModelApiResponse**](ModelApiResponse.md)
+
+### Authorization
+
+No authorization required
+
+### HTTP request headers
+
+ - **Content-Type**: multipart/form-data
+ - **Accept**: application/json
+
+### HTTP response details
+
+| Status code | Description | Response headers |
+|-------------|-------------|------------------|
+**200** | successful operation |  -  |
+
+[[Back to top]](#) [[Back to API list]](../README.md#documentation-for-api-endpoints) [[Back to Model list]](../README.md#documentation-for-models) [[Back to README]](../README.md)
+

samples/openapi3/client/petstore/python-aiohttp/docs/UploadFileWithAdditionalPropertiesRequestObject.md

@@ -0,0 +1,30 @@
+# UploadFileWithAdditionalPropertiesRequestObject
+
+Additional object
+
+## Properties
+
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+**name** | **str** |  | [optional] 
+
+## Example
+
+```python
+from petstore_api.models.upload_file_with_additional_properties_request_object import UploadFileWithAdditionalPropertiesRequestObject
+
+# TODO update the JSON string below
+json = "{}"
+# create an instance of UploadFileWithAdditionalPropertiesRequestObject from a JSON string
+upload_file_with_additional_properties_request_object_instance = UploadFileWithAdditionalPropertiesRequestObject.from_json(json)
+# print the JSON string representation of the object
+print(UploadFileWithAdditionalPropertiesRequestObject.to_json())
+
+# convert the object into a dict
+upload_file_with_additional_properties_request_object_dict = upload_file_with_additional_properties_request_object_instance.to_dict()
+# create an instance of UploadFileWithAdditionalPropertiesRequestObject from a dict
+upload_file_with_additional_properties_request_object_from_dict = UploadFileWithAdditionalPropertiesRequestObject.from_dict(upload_file_with_additional_properties_request_object_dict)
+```
+[[Back to Model list]](../README.md#documentation-for-models) [[Back to API list]](../README.md#documentation-for-api-endpoints) [[Back to README]](../README.md)
+
+

samples/openapi3/client/petstore/python-aiohttp/petstore_api/__init__.py

@@ -141,5 +141,6 @@ from petstore_api.models.test_object_for_multipart_requests_request_marker impor
 from petstore_api.models.tiger import Tiger
 from petstore_api.models.unnamed_dict_with_additional_model_list_properties import UnnamedDictWithAdditionalModelListProperties
 from petstore_api.models.unnamed_dict_with_additional_string_list_properties import UnnamedDictWithAdditionalStringListProperties
+from petstore_api.models.upload_file_with_additional_properties_request_object import UploadFileWithAdditionalPropertiesRequestObject
 from petstore_api.models.user import User
 from petstore_api.models.with_nested_one_of import WithNestedOneOf

samples/openapi3/client/petstore/python-aiohttp/petstore_api/api/fake_api.py

@@ -24,6 +24,7 @@ from petstore_api.models.client import Client
 from petstore_api.models.enum_class import EnumClass
 from petstore_api.models.file_schema_test_class import FileSchemaTestClass
 from petstore_api.models.health_check_result import HealthCheckResult
+from petstore_api.models.model_api_response import ModelApiResponse
 from petstore_api.models.outer_composite import OuterComposite
 from petstore_api.models.outer_enum_integer import OuterEnumInteger
 from petstore_api.models.outer_object_with_enum_property import OuterObjectWithEnumProperty
@@ -31,6 +32,7 @@ from petstore_api.models.pet import Pet
 from petstore_api.models.tag import Tag
 from petstore_api.models.test_inline_freeform_additional_properties_request import TestInlineFreeformAdditionalPropertiesRequest
 from petstore_api.models.test_object_for_multipart_requests_request_marker import TestObjectForMultipartRequestsRequestMarker
+from petstore_api.models.upload_file_with_additional_properties_request_object import UploadFileWithAdditionalPropertiesRequestObject
 from petstore_api.models.user import User
 
 from petstore_api.api_client import ApiClient, RequestSerialized
@@ -9812,3 +9814,306 @@ class FakeApi:
         )
 
 
+
+
+    @validate_call
+    async def upload_file_with_additional_properties(
+        self,
+        file: Annotated[Union[StrictBytes, StrictStr, Tuple[StrictStr, StrictBytes]], Field(description="file to upload")],
+        object: Optional[UploadFileWithAdditionalPropertiesRequestObject] = None,
+        count: Annotated[Optional[StrictInt], Field(description="Integer count")] = None,
+        _request_timeout: Union[
+            None,
+            Annotated[StrictFloat, Field(gt=0)],
+            Tuple[
+                Annotated[StrictFloat, Field(gt=0)],
+                Annotated[StrictFloat, Field(gt=0)]
+            ]
+        ] = None,
+        _request_auth: Optional[Dict[StrictStr, Any]] = None,
+        _content_type: Optional[StrictStr] = None,
+        _headers: Optional[Dict[StrictStr, Any]] = None,
+        _host_index: Annotated[StrictInt, Field(ge=0, le=0)] = 0,
+    ) -> ModelApiResponse:
+        """uploads a file and additional properties using multipart/form-data
+
+        
+
+        :param file: file to upload (required)
+        :type file: bytearray
+        :param object:
+        :type object: UploadFileWithAdditionalPropertiesRequestObject
+        :param count: Integer count
+        :type count: int
+        :param _request_timeout: timeout setting for this request. If one
+                                 number provided, it will be total request
+                                 timeout. It can also be a pair (tuple) of
+                                 (connection, read) timeouts.
+        :type _request_timeout: int, tuple(int, int), optional
+        :param _request_auth: set to override the auth_settings for an a single
+                              request; this effectively ignores the
+                              authentication in the spec for a single request.
+        :type _request_auth: dict, optional
+        :param _content_type: force content-type for the request.
+        :type _content_type: str, Optional
+        :param _headers: set to override the headers for a single
+                         request; this effectively ignores the headers
+                         in the spec for a single request.
+        :type _headers: dict, optional
+        :param _host_index: set to override the host_index for a single
+                            request; this effectively ignores the host_index
+                            in the spec for a single request.
+        :type _host_index: int, optional
+        :return: Returns the result object.
+        """ # noqa: E501
+
+        _param = self._upload_file_with_additional_properties_serialize(
+            file=file,
+            object=object,
+            count=count,
+            _request_auth=_request_auth,
+            _content_type=_content_type,
+            _headers=_headers,
+            _host_index=_host_index
+        )
+
+        _response_types_map: Dict[str, Optional[str]] = {
+            '200': "ModelApiResponse",
+        }
+        response_data = await self.api_client.call_api(
+            *_param,
+            _request_timeout=_request_timeout
+        )
+        await response_data.read()
+        return self.api_client.response_deserialize(
+            response_data=response_data,
+            response_types_map=_response_types_map,
+        ).data
+
+
+    @validate_call
+    async def upload_file_with_additional_properties_with_http_info(
+        self,
+        file: Annotated[Union[StrictBytes, StrictStr, Tuple[StrictStr, StrictBytes]], Field(description="file to upload")],
+        object: Optional[UploadFileWithAdditionalPropertiesRequestObject] = None,
+        count: Annotated[Optional[StrictInt], Field(description="Integer count")] = None,
+        _request_timeout: Union[
+            None,
+            Annotated[StrictFloat, Field(gt=0)],
+            Tuple[
+                Annotated[StrictFloat, Field(gt=0)],
+                Annotated[StrictFloat, Field(gt=0)]
+            ]
+        ] = None,
+        _request_auth: Optional[Dict[StrictStr, Any]] = None,
+        _content_type: Optional[StrictStr] = None,
+        _headers: Optional[Dict[StrictStr, Any]] = None,
+        _host_index: Annotated[StrictInt, Field(ge=0, le=0)] = 0,
+    ) -> ApiResponse[ModelApiResponse]:
+        """uploads a file and additional properties using multipart/form-data
+
+        
+
+        :param file: file to upload (required)
+        :type file: bytearray
+        :param object:
+        :type object: UploadFileWithAdditionalPropertiesRequestObject
+        :param count: Integer count
+        :type count: int
+        :param _request_timeout: timeout setting for this request. If one
+                                 number provided, it will be total request
+                                 timeout. It can also be a pair (tuple) of
+                                 (connection, read) timeouts.
+        :type _request_timeout: int, tuple(int, int), optional
+        :param _request_auth: set to override the auth_settings for an a single
+                              request; this effectively ignores the
+                              authentication in the spec for a single request.
+        :type _request_auth: dict, optional
+        :param _content_type: force content-type for the request.
+        :type _content_type: str, Optional
+        :param _headers: set to override the headers for a single
+                         request; this effectively ignores the headers
+                         in the spec for a single request.
+        :type _headers: dict, optional
+        :param _host_index: set to override the host_index for a single
+                            request; this effectively ignores the host_index
+                            in the spec for a single request.
+        :type _host_index: int, optional
+        :return: Returns the result object.
+        """ # noqa: E501
+
+        _param = self._upload_file_with_additional_properties_serialize(
+            file=file,
+            object=object,
+            count=count,
+            _request_auth=_request_auth,
+            _content_type=_content_type,
+            _headers=_headers,
+            _host_index=_host_index
+        )
+
+        _response_types_map: Dict[str, Optional[str]] = {
+            '200': "ModelApiResponse",
+        }
+        response_data = await self.api_client.call_api(
+            *_param,
+            _request_timeout=_request_timeout
+        )
+        await response_data.read()
+        return self.api_client.response_deserialize(
+            response_data=response_data,
+            response_types_map=_response_types_map,
+        )
+
+
+    @validate_call
+    async def upload_file_with_additional_properties_without_preload_content(
+        self,
+        file: Annotated[Union[StrictBytes, StrictStr, Tuple[StrictStr, StrictBytes]], Field(description="file to upload")],
+        object: Optional[UploadFileWithAdditionalPropertiesRequestObject] = None,
+        count: Annotated[Optional[StrictInt], Field(description="Integer count")] = None,
+        _request_timeout: Union[
+            None,
+            Annotated[StrictFloat, Field(gt=0)],
+            Tuple[
+                Annotated[StrictFloat, Field(gt=0)],
+                Annotated[StrictFloat, Field(gt=0)]
+            ]
+        ] = None,
+        _request_auth: Optional[Dict[StrictStr, Any]] = None,
+        _content_type: Optional[StrictStr] = None,
+        _headers: Optional[Dict[StrictStr, Any]] = None,
+        _host_index: Annotated[StrictInt, Field(ge=0, le=0)] = 0,
+    ) -> RESTResponseType:
+        """uploads a file and additional properties using multipart/form-data
+
+        
+
+        :param file: file to upload (required)
+        :type file: bytearray
+        :param object:
+        :type object: UploadFileWithAdditionalPropertiesRequestObject
+        :param count: Integer count
+        :type count: int
+        :param _request_timeout: timeout setting for this request. If one
+                                 number provided, it will be total request
+                                 timeout. It can also be a pair (tuple) of
+                                 (connection, read) timeouts.
+        :type _request_timeout: int, tuple(int, int), optional
+        :param _request_auth: set to override the auth_settings for an a single
+                              request; this effectively ignores the
+                              authentication in the spec for a single request.
+        :type _request_auth: dict, optional
+        :param _content_type: force content-type for the request.
+        :type _content_type: str, Optional
+        :param _headers: set to override the headers for a single
+                         request; this effectively ignores the headers
+                         in the spec for a single request.
+        :type _headers: dict, optional
+        :param _host_index: set to override the host_index for a single
+                            request; this effectively ignores the host_index
+                            in the spec for a single request.
+        :type _host_index: int, optional
+        :return: Returns the result object.
+        """ # noqa: E501
+
+        _param = self._upload_file_with_additional_properties_serialize(
+            file=file,
+            object=object,
+            count=count,
+            _request_auth=_request_auth,
+            _content_type=_content_type,
+            _headers=_headers,
+            _host_index=_host_index
+        )
+
+        _response_types_map: Dict[str, Optional[str]] = {
+            '200': "ModelApiResponse",
+        }
+        response_data = await self.api_client.call_api(
+            *_param,
+            _request_timeout=_request_timeout
+        )
+        return response_data.response
+
+
+    def _upload_file_with_additional_properties_serialize(
+        self,
+        file,
+        object,
+        count,
+        _request_auth,
+        _content_type,
+        _headers,
+        _host_index,
+    ) -> RequestSerialized:
+
+        _host = None
+
+        _collection_formats: Dict[str, str] = {
+        }
+
+        _path_params: Dict[str, str] = {}
+        _query_params: List[Tuple[str, str]] = []
+        _header_params: Dict[str, Optional[str]] = _headers or {}
+        _form_params: List[Tuple[str, str]] = []
+        _files: Dict[
+            str, Union[str, bytes, List[str], List[bytes], List[Tuple[str, bytes]]]
+        ] = {}
+        _body_params: Optional[bytes] = None
+
+        # process the path parameters
+        # process the query parameters
+        # process the header parameters
+        # process the form parameters
+        if file is not None:
+            _files['file'] = file
+        if object is not None:
+            _form_params.append(('object', object))
+        if count is not None:
+            _form_params.append(('count', count))
+        # process the body parameter
+
+
+        # set the HTTP header `Accept`
+        if 'Accept' not in _header_params:
+            _header_params['Accept'] = self.api_client.select_header_accept(
+                [
+                    'application/json'
+                ]
+            )
+
+        # set the HTTP header `Content-Type`
+        if _content_type:
+            _header_params['Content-Type'] = _content_type
+        else:
+            _default_content_type = (
+                self.api_client.select_header_content_type(
+                    [
+                        'multipart/form-data'
+                    ]
+                )
+            )
+            if _default_content_type is not None:
+                _header_params['Content-Type'] = _default_content_type
+
+        # authentication setting
+        _auth_settings: List[str] = [
+        ]
+
+        return self.api_client.param_serialize(
+            method='POST',
+            resource_path='/fake/upload_file_with_additional_properties',
+            path_params=_path_params,
+            query_params=_query_params,
+            header_params=_header_params,
+            body=_body_params,
+            post_params=_form_params,
+            files=_files,
+            auth_settings=_auth_settings,
+            collection_formats=_collection_formats,
+            _host=_host,
+            _request_auth=_request_auth
+        )
+
+

samples/openapi3/client/petstore/python-aiohttp/petstore_api/models/__init__.py

@@ -116,5 +116,6 @@ from petstore_api.models.test_object_for_multipart_requests_request_marker impor
 from petstore_api.models.tiger import Tiger
 from petstore_api.models.unnamed_dict_with_additional_model_list_properties import UnnamedDictWithAdditionalModelListProperties
 from petstore_api.models.unnamed_dict_with_additional_string_list_properties import UnnamedDictWithAdditionalStringListProperties
+from petstore_api.models.upload_file_with_additional_properties_request_object import UploadFileWithAdditionalPropertiesRequestObject
 from petstore_api.models.user import User
 from petstore_api.models.with_nested_one_of import WithNestedOneOf

samples/openapi3/client/petstore/python-aiohttp/petstore_api/models/upload_file_with_additional_properties_request_object.py

@@ -0,0 +1,87 @@
+# coding: utf-8
+
+"""
+    OpenAPI Petstore
+
+    This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+
+    The version of the OpenAPI document: 1.0.0
+    Generated by OpenAPI Generator (https://openapi-generator.tech)
+
+    Do not edit the class manually.
+"""  # noqa: E501
+
+
+from __future__ import annotations
+import pprint
+import re  # noqa: F401
+import json
+
+from pydantic import BaseModel, ConfigDict, StrictStr
+from typing import Any, ClassVar, Dict, List, Optional
+from typing import Optional, Set
+from typing_extensions import Self
+
+class UploadFileWithAdditionalPropertiesRequestObject(BaseModel):
+    """
+    Additional object
+    """ # noqa: E501
+    name: Optional[StrictStr] = None
+    __properties: ClassVar[List[str]] = ["name"]
+
+    model_config = ConfigDict(
+        populate_by_name=True,
+        validate_assignment=True,
+        protected_namespaces=(),
+    )
+
+
+    def to_str(self) -> str:
+        """Returns the string representation of the model using alias"""
+        return pprint.pformat(self.model_dump(by_alias=True))
+
+    def to_json(self) -> str:
+        """Returns the JSON representation of the model using alias"""
+        # TODO: pydantic v2: use .model_dump_json(by_alias=True, exclude_unset=True) instead
+        return json.dumps(self.to_dict())
+
+    @classmethod
+    def from_json(cls, json_str: str) -> Optional[Self]:
+        """Create an instance of UploadFileWithAdditionalPropertiesRequestObject from a JSON string"""
+        return cls.from_dict(json.loads(json_str))
+
+    def to_dict(self) -> Dict[str, Any]:
+        """Return the dictionary representation of the model using alias.
+
+        This has the following differences from calling pydantic's
+        `self.model_dump(by_alias=True)`:
+
+        * `None` is only added to the output dict for nullable fields that
+          were set at model initialization. Other fields with value `None`
+          are ignored.
+        """
+        excluded_fields: Set[str] = set([
+        ])
+
+        _dict = self.model_dump(
+            by_alias=True,
+            exclude=excluded_fields,
+            exclude_none=True,
+        )
+        return _dict
+
+    @classmethod
+    def from_dict(cls, obj: Optional[Dict[str, Any]]) -> Optional[Self]:
+        """Create an instance of UploadFileWithAdditionalPropertiesRequestObject from a dict"""
+        if obj is None:
+            return None
+
+        if not isinstance(obj, dict):
+            return cls.model_validate(obj)
+
+        _obj = cls.model_validate({
+            "name": obj.get("name")
+        })
+        return _obj
+
+

samples/openapi3/client/petstore/python-aiohttp/petstore_api/rest.py

@@ -184,6 +184,11 @@ class RESTClientObject:
                             content_type=v[2]
                         )
                     else:
+                        # Ensures that dict objects are serialized
+                        if isinstance(v, dict):
+                            v = json.dumps(v)
+                        elif isinstance(v, int):
+                            v = str(v)
                         data.add_field(k, v)
                 args["data"] = data
 
@@ -208,8 +213,3 @@ class RESTClientObject:
         r = await pool_manager.request(**args)
 
         return RESTResponse(r)
-
-
-
-
-

samples/openapi3/client/petstore/python-aiohttp/test/test_upload_file_with_additional_properties_request_object.py

@@ -0,0 +1,51 @@
+# coding: utf-8
+
+"""
+    OpenAPI Petstore
+
+    This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+
+    The version of the OpenAPI document: 1.0.0
+    Generated by OpenAPI Generator (https://openapi-generator.tech)
+
+    Do not edit the class manually.
+"""  # noqa: E501
+
+
+import unittest
+
+from petstore_api.models.upload_file_with_additional_properties_request_object import UploadFileWithAdditionalPropertiesRequestObject
+
+class TestUploadFileWithAdditionalPropertiesRequestObject(unittest.TestCase):
+    """UploadFileWithAdditionalPropertiesRequestObject unit test stubs"""
+
+    def setUp(self):
+        pass
+
+    def tearDown(self):
+        pass
+
+    def make_instance(self, include_optional) -> UploadFileWithAdditionalPropertiesRequestObject:
+        """Test UploadFileWithAdditionalPropertiesRequestObject
+            include_optional is a boolean, when False only required
+            params are included, when True both required and
+            optional params are included """
+        # uncomment below to create an instance of `UploadFileWithAdditionalPropertiesRequestObject`
+        """
+        model = UploadFileWithAdditionalPropertiesRequestObject()
+        if include_optional:
+            return UploadFileWithAdditionalPropertiesRequestObject(
+                name = ''
+            )
+        else:
+            return UploadFileWithAdditionalPropertiesRequestObject(
+        )
+        """
+
+    def testUploadFileWithAdditionalPropertiesRequestObject(self):
+        """Test UploadFileWithAdditionalPropertiesRequestObject"""
+        # inst_req_only = self.make_instance(include_optional=False)
+        # inst_req_and_optional = self.make_instance(include_optional=True)
+
+if __name__ == '__main__':
+    unittest.main()

samples/openapi3/client/petstore/python-aiohttp/tests/test_rest.py

@@ -0,0 +1,74 @@
+import os
+import unittest
+from unittest.mock import AsyncMock, Mock, patch
+
+import petstore_api
+
+
+def get_field_from_formdata(formdata, name):
+    return next(filter(lambda x: x[0]["name"] == name, formdata._fields))[-1]
+
+
+class TestMultipleResponseTypes(unittest.IsolatedAsyncioTestCase):
+    def setUpFiles(self):
+        self.test_file_dir = os.path.join(os.path.dirname(__file__), "..", "testfiles")
+        self.test_file_dir = os.path.realpath(self.test_file_dir)
+        self.test_file_path = os.path.join(self.test_file_dir, "foo.png")
+
+    def setUp(self):
+        self.setUpFiles()
+
+    async def test_multipart_requests(self):
+        mock_resp = AsyncMock()
+        mock_resp.return_value.read.return_value = b"some text"
+        mock_resp.return_value.status = 200
+        mock_resp.return_value.headers = {}
+
+        marker = petstore_api.TestObjectForMultipartRequestsRequestMarker(
+            name="name",
+        )
+
+        with patch("aiohttp.ClientSession.request", mock_resp):
+            async with petstore_api.ApiClient() as api_client:
+                fake_api = petstore_api.FakeApi(api_client)
+                await fake_api.test_object_for_multipart_requests(marker=marker)
+
+        # success if no errors
+
+    async def test_multipart_requests_with_file_and_additional_properties(self):
+        mock_resp = Mock()
+        mock_resp.status = 200
+        mock_resp.read = AsyncMock(
+            return_value=b'{"code": 200, "type": "success", "message": "OK"}'
+        )
+        mock_resp.headers = {"Content-Type": "application/json"}
+
+        mock_request = AsyncMock(return_value=mock_resp)
+        with open(self.test_file_path, "rb") as f, patch(
+            "aiohttp.ClientSession.request", mock_request
+        ):
+            async with petstore_api.ApiClient() as api_client:
+                fake_api = petstore_api.FakeApi(api_client)
+                returned = await fake_api.upload_file_with_additional_properties(
+                    file=(self.test_file_path, f.read()),
+                    count=100,
+                    object=petstore_api.UploadFileWithAdditionalPropertiesRequestObject(
+                        name="foo"
+                    ),
+                )
+
+        assert (
+            returned.code == 200
+            and returned.type == "success"
+            and returned.message == "OK"
+        )
+
+        mock_request.assert_called_once()
+
+        formdata = mock_request.call_args_list[0].kwargs["data"]
+
+        data_object = get_field_from_formdata(formdata, "object")
+        data_count = get_field_from_formdata(formdata, "count")
+
+        assert type(data_count) is str
+        assert type(data_object) is str