app/api/errors.py

from fastapi import FastAPI, Request
from fastapi.exceptions import RequestValidationError
from fastapi.responses import JSONResponse

from app.exceptions.domain import BusinessRuleError, ConflictError, NotFoundError


def register_exception_handlers(app: FastAPI) -> None:
    @app.exception_handler(NotFoundError)
    async def handle_not_found(_: Request, exc: NotFoundError) -> JSONResponse:
        return JSONResponse(status_code=404, content={"detail": str(exc)})

    @app.exception_handler(ConflictError)
    async def handle_conflict(_: Request, exc: ConflictError) -> JSONResponse:
        return JSONResponse(status_code=409, content={"detail": str(exc)})

    @app.exception_handler(BusinessRuleError)
    async def handle_business_rule(_: Request, exc: BusinessRuleError) -> JSONResponse:
        return JSONResponse(status_code=422, content={"detail": str(exc)})

    @app.exception_handler(RequestValidationError)
    async def handle_validation(_: Request, exc: RequestValidationError) -> JSONResponse:
        return JSONResponse(status_code=400, content={"detail": exc.errors()})