Prevent error url parameter

[juanber84]

Scenario: GET endpoint with url parameter in your openapi.json.

The original code set the base url of request in url named var before that the lib set parameters config, so the value of url param will be wrong.

[dbanty]

I'm confused by when this would happen. Can you add a test to end-to-end tests which illustrates the problem (and will ensure it doesn't pop back up)?

[juanber84]

Hi, of course. I try explain the problem.

For example we have a openapi.json file with the following content.

{
    "openapi": "3.0.2",
    "info": {
        "title": "FastAPI",
        "version": "0.1.0"
    },
    "paths": {
        "/": {
            "get": {
                "summary": "Root",
                "operationId": "root__get",
                "parameters": [
                    {
                        "required": false,
                        "schema": {
                            "title": "Url",
                            "type": "string"
                        },
                        "name": "url",
                        "in": "query"
                    }
                ],
                "responses": {
                    "200": {
                        "description": "Successful Response",
                        "content": {
                            "application/json": {
                                "schema": {}
                            }
                        }
                    },
                    "422": {
                        "description": "Validation Error",
                        "content": {
                            "application/json": {
                                "schema": {
                                    "$ref": "#/components/schemas/HTTPValidationError"
                                }
                            }
                        }
                    }
                }
            }
        }
    },
    "components": {
        "schemas": {
            "HTTPValidationError": {
                "title": "HTTPValidationError",
                "type": "object",
                "properties": {
                    "detail": {
                        "title": "Detail",
                        "type": "array",
                        "items": {
                            "$ref": "#/components/schemas/ValidationError"
                        }
                    }
                }
            },
            "ValidationError": {
                "title": "ValidationError",
                "required": [
                    "loc",
                    "msg",
                    "type"
                ],
                "type": "object",
                "properties": {
                    "loc": {
                        "title": "Location",
                        "type": "array",
                        "items": {
                            "anyOf": [
                                {
                                    "type": "string"
                                },
                                {
                                    "type": "integer"
                                }
                            ]
                        }
                    },
                    "msg": {
                        "title": "Message",
                        "type": "string"
                    },
                    "type": {
                        "title": "Error Type",
                        "type": "string"
                    }
                }
            }
        }
    }
}

You can see that we have a endpoint / which recived one parameter named "url".

Next, we can use your tool to generate the client.

openapi-python-client generate --path ./openapi.json

The tool generate the client us.

fast-api-client
├── README.md
├── fast_api_client
│   ├── __init__.py
│   ├── api
│   │   ├── __init__.py
│   │   └── default
│   │       ├── __init__.py
│   │       └── root_get.py
│   ├── client.py
│   ├── errors.py
│   ├── models
│   │   ├── __init__.py
│   │   ├── http_validation_error.py
│   │   └── validation_error.py
│   ├── py.typed
│   └── types.py
└── pyproject.toml

And finally, the code generated by the tool in root_get.py is.

from http import HTTPStatus
from typing import Any, Dict, Optional, Union, cast

import httpx

from ... import errors
from ...client import Client
from ...models.http_validation_error import HTTPValidationError
from ...types import UNSET, Response, Unset


def _get_kwargs(
    *,
    client: Client,
    url: Union[Unset, None, str] = UNSET,
) -> Dict[str, Any]:
    url = "{}/".format(client.base_url)

    headers: Dict[str, str] = client.get_headers()
    cookies: Dict[str, Any] = client.get_cookies()

    params: Dict[str, Any] = {}
    params["url"] = url

    params = {k: v for k, v in params.items() if v is not UNSET and v is not None}

    return {
        "method": "get",
        "url": url,
        "headers": headers,
        "cookies": cookies,
        "timeout": client.get_timeout(),
        "follow_redirects": client.follow_redirects,
        "params": params,
    }
...
...
...
...

Bug

def _get_kwargs(
    *,
    client: Client,
    url: Union[Unset, None, str] = UNSET, <====================================
) -> Dict[str, Any]:
    url = "{}/".format(client.base_url) <======================================

    headers: Dict[str, str] = client.get_headers()
    cookies: Dict[str, Any] = client.get_cookies()

    params: Dict[str, Any] = {}
    params["url"] = url <======================================================

    params = {k: v for k, v in params.items() if v is not UNSET and v is not None}

The tool is overwriting my url parameter with the value of api endpoint

Solution

If you move the url endpoint var setting after params generation you can fix the problem

[dbanty]

Thank you for that, I get it now! I think this is very similar to #758 actually and I'd like to handle it the same way (treat url as a reserved word) since I think relying on the position in the code could end up with more bugs in the future if someone ends up moving it or adding more param logic later.

So I'm going to close this PR and instead solve both of these problems together. Thank you for reporting!