PySimpleSocial/util/exception_handlers.py

from config import LOGGER, NotAuthenticated
from fastapi import Request
from fastapi.responses import JSONResponse
from fastapi.exceptions import RequestValidationError
from fastapi.exceptions import HTTPException, StarletteHTTPException
from slowapi.errors import RateLimitExceeded


async def rate_limited(request: Request, error: RateLimitExceeded) -> JSONResponse:
    """
    Handles the equivalent of a 429 Too Many Requests error
    """

    n = 0
    while True:
        if error.detail[n].isnumeric():
            n += 1
        else:
            break
    error.detail = error.detail[:n] + " requests" + error.detail[n:]
    LOGGER.info(f"{request.client.host} got rate-limited at {str(request.url)} " f"(exceeded {error.detail})")
    return JSONResponse(
        status_code=200,
        content=dict(
            status_code=429,
            msg=f"Too many requests, retry after {error.detail[error.detail.find('per') + 4:]}",
        ),
    )


def not_authenticated(request: Request, _: NotAuthenticated) -> JSONResponse:
    """
    Handles the equivalent of a 401 Unauthorized exception
    """

    LOGGER.info(f"{request.client.host} failed to authenticate at {str(request.url)}")
    return JSONResponse(status_code=200, content=dict(status_code=401, msg="Authentication is required"))


def request_invalid(request: Request, exc: RequestValidationError) -> JSONResponse:
    """
    Handles Bad Request exceptions from FastAPI
    """

    LOGGER.info(f"{request.client.host} sent an invalid request at {request.url!r}:  {type(exc).__name__}: {exc}")
    return JSONResponse(
        status_code=200,
        content=dict(status_code=400, msg=f"Bad request: {type(exc).__name__}: {exc}"),
    )


def http_exception(request: Request, exc: HTTPException | StarletteHTTPException) -> JSONResponse:
    """
    Handles HTTP-specific exceptions raised explicitly by
    path operations
    """

    if exc.status_code >= 500:
        LOGGER.error(
            f"{request.client.host} raised a {exc.status_code} error at {request.url!r}:" f"{type(exc).__name__}: {exc}"
        )
        return JSONResponse(status_code=200, content=dict(status_code=500, msg="Internal Server Error"))
    else:
        LOGGER.info(f"{request.client.host} raised an HTTP error ({exc.status_code}) at {str(request.url)}")
        return JSONResponse(status_code=200, content=dict(status_code=exc.status_code, msg=exc.detail))


async def generic_error(request: Request, exc: Exception) -> JSONResponse:
    """
    Handles generic, unexpected errors in the ASGI application
    """

    LOGGER.info(f"{request.client.host} raised an unexpected error ({type(exc).__name__}: {exc}) at {str(request.url)}")
    # We can't leak anything about the error, it would be too risky
    return JSONResponse(status_code=200, content=dict(status_code=500, msg="Internal Server Error"))