[PYTHON-FLASK] Problem posting with x-www-form-urlencoded

Description

My python flask server is crashing when posting url encoded post parameter.

openapi-generator version

5.0.0

OpenAPI declaration file content or url

---
openapi: 3.0.3
servers:
  - url: 'https://my.api.com'
info:
  version: 1.0
  title: A test API
paths:
  /login:
    post:
      operationId: login
      requestBody:
        required: true
        content:
          application/x-www-form-urlencoded:
            schema:
                $ref: '#/components/schemas/LogInInfo'
      responses:
        '200':
          description: Login successfull
components:
  schemas:
    LogInInfo:
      type: object
      required:
        - email
        - password
      properties:
        email:
          type: string
        password:
          type: string

Command line used for generation

openapi-generator generate -g python-flask -i api.yaml

Steps to reproduce

1. Generate the flask server
2. Run it with python -m openapi_server
3. Make a post request on the path /login
4. See the crash log:

$ python -m openapi_server
 * Serving Flask app "__main__" (lazy loading)
 * Environment: production
   WARNING: This is a development server. Do not use it in a production deployment.
   Use a production WSGI server instead.
 * Debug mode: off
 * Running on http://0.0.0.0:8080/ (Press CTRL+C to quit)
[2021-01-28 20:05:12,933] ERROR in app: Exception on /login [POST]
Traceback (most recent call last):
  File "/usr/local/lib/python3.9/site-packages/flask/app.py", line 2447, in wsgi_app
    response = self.full_dispatch_request()
  File "/usr/local/lib/python3.9/site-packages/flask/app.py", line 1952, in full_dispatch_request
    rv = self.handle_user_exception(e)
  File "/usr/local/lib/python3.9/site-packages/flask/app.py", line 1821, in handle_user_exception
    reraise(exc_type, exc_value, tb)
  File "/usr/local/lib/python3.9/site-packages/flask/_compat.py", line 39, in reraise
    raise value
  File "/usr/local/lib/python3.9/site-packages/flask/app.py", line 1950, in full_dispatch_request
    rv = self.dispatch_request()
  File "/usr/local/lib/python3.9/site-packages/flask/app.py", line 1936, in dispatch_request
    return self.view_functions[rule.endpoint](**req.view_args)
  File "/usr/local/lib/python3.9/site-packages/connexion/decorators/decorator.py", line 48, in wrapper
    response = function(request)
  File "/usr/local/lib/python3.9/site-packages/connexion/decorators/uri_parsing.py", line 144, in wrapper
    response = function(request)
  File "/usr/local/lib/python3.9/site-packages/connexion/decorators/validation.py", line 184, in wrapper
    response = function(request)
  File "/usr/local/lib/python3.9/site-packages/connexion/decorators/parameter.py", line 121, in wrapper
    return function(**kwargs)
TypeError: login() missing 2 required positional arguments: 'email' and 'password'
127.0.0.1 - - [28/Jan/2021 20:05:12] "POST /login HTTP/1.1" 500 -

Related issues/PRs

Not that I know.

Suggest a fix/enhancement

I manage to fix it by replacing the openapi_server/controllers/default_controller.py code:

import connexion
import six

from openapi_server import util


def login(email, password):  # noqa: E501
    """login

     # noqa: E501

    :param email: 
    :type email: str
    :param password: 
    :type password: str

    :rtype: None
    """
    return

With:

import connexion
import six

from openapi_server import util


def login(**kwargs):  # noqa: E501
    email = kwargs["body"]["email"]
    password = kwargs["body"]["password"]
    """login

     # noqa: E501

    :param email: 
    :type email: str
    :param password: 
    :type password: str

    :rtype: None
    """
    return

Any idea what is going wrong ?

Start with the generated openapi_server/controllers/default_controller.py and the provided OpenAPI declaration, then reproduce the issue using the documented openapi-generator command and POST to /login. Done means the generated Flask server accepts application/x-www-form-urlencoded email and password parameters without crashing.