return HTTPException in async_db_request_handler

[nurlybek-dev]

Hello,
Problem, when exception raised in service with async_db_request_handler decorator, it return HTTPException, which FastAPI can't serialize and raised another exception

fastapi.exceptions.ResponseValidationError: 1 validation errors:
{'loc': ('response',), 'msg': 'value is not a valid dict', 'type': 'type_error.dict'}

code example:
Controller

@Get("/")
async def get_accounts(session: AsyncSession = Depends(config.get_db)):
    return await self.service.get_list(session)

Service

@async_db_request_handler
async def get_list(self, session: AsyncSession):
    query = select(Entity)

    if True:
        raise ValueError("ERROR")

    result = await session.execute(query)
    return result.scalars().all()

---

Maybe it should be raise HTTPException instead of return HTTPException?
code line
nest/core/decorators/database.py:82.

[ItayTheDar]

@nurlybek-dev Hi!

I believe you are correct. When the service layer return an exception, then the controller does not know that an error was raised and it breaking the exceptions chain. I will work on pr that fix it.

[ItayTheDar]

Resolved by the DI/runtime rewrite in #125. db_request_handler and async_db_request_handler now re-raise existing HTTPException instances and convert unexpected exceptions with raise HTTPException(...) rather than returning an exception object for response serialization.

The original async failure pattern was reproduced against current main and correctly raises an HTTP 500 exception. Closing as completed.