Raise exception from background task on BaseHTTPMiddleware introduced a bug? #2893
Description
Looking at this commit, it pushed the logic out to the end, but if there is an error raised and handled, it will reraise it again
Steps to reproduce.
@app.get("/error")
async def foo():
exc = Exception("foobar")
exc.status_code = 501
raise excMiddleware handler.
@app.middleware("http")
async def http_middleware(request: Request, call_next):
try:
response = await call_next(request)
except Exception as exc:
logger.exception("Failure in user code!")
# stuff in between
response = JSONResponse(
{"error": str(exc), "stacktrace": traceback.format_exc()},
status_code=status_code,
)
return response trace
During handling of the above exception, another exception occurred:
request = <starlette.middleware.base._CachedRequest object at 0x13a837040>
async def call_next(request: Request) -> Response:
async def receive_or_disconnect() -> Message:
if response_sent.is_set():
return {"type": "http.disconnect"}
async with anyio.create_task_group() as task_group:
async def wrap(func: typing.Callable[[], typing.Awaitable[T]]) -> T:
result = await func()
task_group.cancel_scope.cancel()
return result
task_group.start_soon(wrap, response_sent.wait)
message = await wrap(wrapped_receive)
if response_sent.is_set():
return {"type": "http.disconnect"}
return message
async def send_no_error(message: Message) -> None:
try:
await send_stream.send(message)
except anyio.BrokenResourceError:
# recv_stream has been closed, i.e. response_sent has been set.
return
async def coro() -> None:
nonlocal app_exc
with send_stream:
try:
await self.app(scope, receive_or_disconnect, send_no_error)
except Exception as exc:
app_exc = exc
task_group.start_soon(coro)
try:
> message = await recv_stream.receive()
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
self = MemoryObjectReceiveStream(_state=MemoryObjectStreamState(max_buffer_size=0, buffer=deque([]), open_send_channels=0, open_receive_channels=0, waiting_receivers=OrderedDict(), waiting_senders=OrderedDict()), _closed=True)
async def receive(self) -> T_co:
await checkpoint()
try:
return self.receive_nowait()
except WouldBlock:
# Add ourselves in the queue
receive_event = Event()
receiver = MemoryObjectItemReceiver[T_co]()
self._state.waiting_receivers[receive_event] = receiver
try:
await receive_event.wait()
finally:
self._state.waiting_receivers.pop(receive_event, None)
try:
return receiver.item
except AttributeError:
> raise EndOfStream
E anyio.EndOfStream