[BUG][python-experimental] calling a delete method with just a path parameter fails

[MAKOMO]

Bug Report Checklist

• Have you provided a full/minimal spec to reproduce the issue?
• Have you validated the input using an OpenAPI validator (example)?
• Have you tested with the latest master to confirm the issue still exists?
• Have you searched for related issues/PRs?
• What's the actual output vs expected output?
• [Optional] Sponsorship to speed up the bug fix or feature request (example)

Description

Calling a delete method with just a path parameter fails with

# python3 bug.py
Exception when calling Api: (0)
Reason: Cannot prepare a request message for provided
                             arguments. Please check that your arguments match
                             declared content type.

This works with a client generated with the standard python generator, changing the method call to

#main_api_instance.delete_coffee(path_params={"id":"12"})
main_api_instance.delete_coffee(12)

openapi-generator version

OpenAPI declaration file content or url

openapi: 3.0.3
info:
  title: delete
  description: delete with empty body
  version: 0.0.1
tags:
  - name: main
servers:
  - url: https://localhost:62602/api/v1
    description: Production server
paths:
  "/coffees/{id}":
    delete:
      operationId: deleteCoffee
      summary: Delete coffee
      description: Delete the coffee identified by the given id
      tags:
        - main
      parameters:
        - name: id
          in: path
          description: The internal object id
          required: true
          schema:
            type: string
      responses:
        "200":
          description: OK
        default:
          description: Unexpected error

Generation Details

Client generated with the current python_experimental from trunk

Steps to reproduce

# java -jar ./tools/Generator/openapi-generator/modules/openapi-generator-cli/target/openapi-generator-cli.jar generate -i delete-bug.yaml -g python-experimental -o ./_build/client/
# cd _build/client
# sudo python3 setup.py install
# cd
# python3 bug.py 

with bug.py as follows

from pprint import pprint
import time

import openapi_client
from openapi_client.api import main_api

# Logging
import os
import logging
logging.basicConfig(level=os.environ.get("LOGLEVEL", "DEBUG"))


# Configure API
configuration = openapi_client.Configuration(
  server_index = 0
)
configuration.verify_ssl = False
configuration.debug = True


# Enter a context with an instance of the API client    
with openapi_client.ApiClient(configuration) as api_client:
    try:
        main_api_instance = main_api.MainApi(api_client)
        main_api_instance.delete_coffee(path_params={"id":"12"})
        #main_api_instance.delete_coffee(12)
    except openapi_client.ApiException as e:
        print("Exception when calling Api: %s\n" % e)

Related issues/PRs

None found

Suggest a fix

This fails in rest.py:request() which is called with

method=DELETE
url=https://localhost:62602/api/v1/coffees/12
query_params=None
headers?{'User-Agent': 'OpenAPI-Generator/1.0.0/python'}
fields=None
body=None

as body is None. Maybe body should be the empty string here?

It works in the client generated with the standard python generator as this is covered by the first case as 'Content-Type' not in headers.

Maybe here the case of body=None and query_params=None with Content-Type not in headers should be covered here by setting the body=""?

[spacether]

@MAKOMO want to submit a PR fixing this? Is it blocked by the double encoding fix?

[MAKOMO]

@spacether : I would love to, but I feel that I do not have enough understanding of the intended architecture of all of this. Of course I could submit a PR with a quick fix, but that might break other things. I am also not even sure that what I am doing should work at all as I am not too firm in the OpenAPI specification language itself.

[MAKOMO]

I see no relation to the double encoding issue.

[spacether]

Hmm this is happening because there is no body in the request so there is no content-type.
You hit a corner case. Let me fix it.

[spacether]

Fixed!