Bug: Response examples are not generated even with `generate_examples=True` about litestar

[provinzkraut]

You need to set create_examples=True on the application itself; It is off by default.

from litestar import Litestar
from litestar.openapi import OpenAPIConfig

app = Litestar(
    openapi_config=OpenAPIConfig(
        create_examples=True,
        title="OpenAPI",
        version="1.0.0",
    ),
)

[tuukkamustonen]

Thanks. Just couldn't find it, docs don't mention it (one more thing to add there...)

Though, I have an actual application (ie. not MCVE) that I'm converting, and it doesn't have create_examples=True set, yet it generates those examples. So, there must be bug/glitch in there somewhere.

I will debug more (probably tomorrow) and report back.

[tuukkamustonen]

@provinzkraut Okay, traced it out. This one's actually quite funny. In my actual app, I had annotated the response type as dict[str, Any] and not as Response (temporarily, for laziness) as the return type of the endpoint, like:

from typing import Any

import uvicorn
from litestar import Litestar, post
from litestar.openapi import ResponseSpec
from pydantic import BaseModel


class Response(BaseModel):
    text: str
    num: int


@post("/", responses={201: ResponseSpec(Response)})
async def endpoint() -> dict[str, Any]:  # <---- HERE
    return {"text": "hello", "num": 1}


app = Litestar(
    route_handlers=[endpoint],
)

uvicorn.run(app)

This leads to Litestar _generating examples. Annotating the function return type with the Pydantic model, it does not (as create_examples=False).

My usage here is wrong (annotating a different type than in @post(responses=...)). However, I think the validation could be stricter, perhaps so that this would rather raise, then proceed with unexpected(?) behavior. What do you think?

[provinzkraut]

Just to confirm, this only happens when you include a ResponseSpec?

[tuukkamustonen]

Yes. It reproduces with dict[str, Any] as response type and with ResponseSpec defined.

With dict[str, Any] and without ResponseSpec the whole component is missing from the schema (probably as supposed):

{
  "info": {
    "title": "Litestar API",
    "version": "1.0.0"
  },
  "openapi": "3.1.0",
  "servers": [
    {
      "url": "/"
    }
  ],
  "paths": {
    "/": {
      "post": {
        "summary": "Endpoint",
        "operationId": "Endpoint",
        "responses": {
          "201": {
            "description": "Document created, URL follows",
            "headers": {},
            "content": {
              "application/json": {
                "schema": {
                  "additionalProperties": {},
                  "type": "object"
                }
              }
            }
          }
        },
        "deprecated": false
      }
    }
  },
  "components": {
    "schemas": {}
  }
}