General responses not being added to swagger unless there is an endpoint with a 422

[ajstewart]

I'm not adding this as an issue as I have a feeling it's FastAPI behaviour, but when trying to get the 4XX and 5XX responses on Swagger I noticed they don't show up until you have at least one endpoint with some validation, e.g.:

No 4XX, 5XX

import fastapi
import fastapi_problem.handler

app = fastapi.FastAPI()
eh = fastapi_problem.handler.new_exception_handler()
fastapi_problem.handler.add_exception_handler(app, eh)

@app.get("/")
async def root() -> str:
    """Root endpoint."""
    return "str"

Now it will show with:

import fastapi
import fastapi_problem.handler

app = fastapi.FastAPI()
eh = fastapi_problem.handler.new_exception_handler()
fastapi_problem.handler.add_exception_handler(app, eh)

@app.get("/")
async def root(test: str) -> str:
    """Root endpoint."""
    return "str"

Is there a way around this?

On a side note, many thanks for publishing this library, it's really nice!

[ajstewart]

To follow up on my own question above, when I added auth to my app, if I did the scenario above (i.e. no query params) then the addition of the event handler actually causes swagger to crash and not load. It seems like I have to have a query parameter/something that causes a 422 somewhere on one of my endpoints to have the openapi swagger load.

[ajstewart]

I see the issue in the code, I will close this and create an issue with a PR.