[Django] #34451: Incorrect handling of ImproperlyConfigured Exception in views in ASGI context

Django

unread,

Mar 31, 2023, 6:20:13 AM3/31/23

to django-...@googlegroups.com

#34451: Incorrect handling of ImproperlyConfigured Exception in views in ASGI
context
------------------------------------------+------------------------
Reporter: Michael Galler | Owner: nobody
Type: Bug | Status: new
Component: Uncategorized | Version: 4.1
Severity: Normal | Keywords:
Triage Stage: Unreviewed | Has patch: 0
Needs documentation: 0 | Needs tests: 0
Patch needs improvement: 0 | Easy pickings: 0
UI/UX: 0 |
------------------------------------------+------------------------
start with

{{{
django-admin startproject myproject
}}}

views.py
{{{

from django.views.generic import FormView

class TestView(FormView):

async def post(self, request, *args, **kwargs):
return 'Foobar'
}}}

urls.py
{{{
from django.contrib import admin
from django.urls import path

from myproject.views import TestView

urlpatterns = [
path('admin/', admin.site.urls),
path('test/', TestView.as_view()),
]
}}}

This should raise
django.core.exceptions.ImproperlyConfigured: TestView HTTP handlers must
either be all sync or all async.

Running the devserver via manage.py results in

{{{
C:\code\myproject\venv\Scripts\python.exe C:\code\myproject\manage.py
runserver 8000
Performing system checks...

Watching for file changes with StatReloader
Exception in thread django-main-thread:
Traceback (most recent call last):
File "C:\Program Files\Python311\Lib\threading.py", line 1038, in
_bootstrap_inner
self.run()
File "C:\Program Files\Python311\Lib\threading.py", line 975, in run
self._target(*self._args, **self._kwargs)
File "C:\code\myproject\venv\Lib\site-
packages\django\utils\autoreload.py", line 64, in wrapper
fn(*args, **kwargs)
File "C:\code\myproject\venv\Lib\site-
packages\django\core\management\commands\runserver.py", line 134, in
inner_run
self.check(display_num_errors=True)
File "C:\code\myproject\venv\Lib\site-
packages\django\core\management\base.py", line 475, in check
all_issues = checks.run_checks(
^^^^^^^^^^^^^^^^^^
File "C:\code\myproject\venv\Lib\site-
packages\django\core\checks\registry.py", line 88, in run_checks
new_errors = check(app_configs=app_configs, databases=databases)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\code\myproject\venv\Lib\site-
packages\django\core\checks\urls.py", line 14, in check_url_config
return check_resolver(resolver)
^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\code\myproject\venv\Lib\site-
packages\django\core\checks\urls.py", line 24, in check_resolver
return check_method()
^^^^^^^^^^^^^^
File "C:\code\myproject\venv\Lib\site-
packages\django\urls\resolvers.py", line 494, in check
for pattern in self.url_patterns:
^^^^^^^^^^^^^^^^^
File "C:\code\myproject\venv\Lib\site-
packages\django\utils\functional.py", line 57, in __get__
res = instance.__dict__[self.name] = self.func(instance)
^^^^^^^^^^^^^^^^^^^
File "C:\code\myproject\venv\Lib\site-
packages\django\urls\resolvers.py", line 715, in url_patterns
patterns = getattr(self.urlconf_module, "urlpatterns",
self.urlconf_module)
^^^^^^^^^^^^^^^^^^^
File "C:\code\myproject\venv\Lib\site-
packages\django\utils\functional.py", line 57, in __get__
res = instance.__dict__[self.name] = self.func(instance)
^^^^^^^^^^^^^^^^^^^
File "C:\code\myproject\venv\Lib\site-
packages\django\urls\resolvers.py", line 708, in urlconf_module
return import_module(self.urlconf_name)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\Program Files\Python311\Lib\importlib\__init__.py", line 126,
in import_module
return _bootstrap._gcd_import(name[level:], package, level)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "<frozen importlib._bootstrap>", line 1206, in _gcd_import
File "<frozen importlib._bootstrap>", line 1178, in _find_and_load
File "<frozen importlib._bootstrap>", line 1149, in
_find_and_load_unlocked
File "<frozen importlib._bootstrap>", line 690, in _load_unlocked
File "<frozen importlib._bootstrap_external>", line 940, in exec_module
File "<frozen importlib._bootstrap>", line 241, in
_call_with_frames_removed
File "C:\code\myproject\myproject\urls.py", line 8, in <module>
path('test/', TestView.as_view()),
^^^^^^^^^^^^^^^^^^
File "C:\code\myproject\venv\Lib\site-
packages\django\views\generic\base.py", line 119, in as_view
if cls.view_is_async:
^^^^^^^^^^^^^^^^^
File "C:\code\myproject\venv\Lib\site-
packages\django\utils\functional.py", line 71, in __get__
return self.fget(cls)
^^^^^^^^^^^^^^
File "C:\code\myproject\venv\Lib\site-
packages\django\views\generic\base.py", line 73, in view_is_async
raise ImproperlyConfigured(
django.core.exceptions.ImproperlyConfigured: TestView HTTP handlers must
either be all sync or all async.

}}}

Now the same thing with hypercorn will result in some sort of recursion
that I do not understand.
Uvicorn behaves the same way.

{{{
(venv) λ hypercorn myproject.asgi:application
[2023-03-31 11:54:00 +0200] [16000] [WARNING] ASGI Framework Lifespan
error, continuing without Lifespan support
[2023-03-31 11:54:00 +0200] [16000] [INFO] Running on
http://127.0.0.1:8000 (CTRL + C to quit)
[2023-03-31 11:54:08 +0200] [16000] [ERROR] Error in ASGI Framework
Traceback (most recent call last):
File "C:\code\myproject\venv\Lib\site-packages\asgiref\sync.py", line
486, in thread_handler
raise exc_info[1]
File "C:\code\myproject\venv\Lib\site-
packages\django\core\handlers\exception.py", line 43, in inner
response = await get_response(request)
^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\code\myproject\venv\Lib\site-
packages\django\core\handlers\base.py", line 235, in _get_response_async
callback, callback_args, callback_kwargs =
self.resolve_request(request)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\code\myproject\venv\Lib\site-
packages\django\core\handlers\base.py", line 313, in resolve_request
resolver_match = resolver.resolve(request.path_info)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\code\myproject\venv\Lib\site-
packages\django\urls\resolvers.py", line 663, in resolve
for pattern in self.url_patterns:
^^^^^^^^^^^^^^^^^
File "C:\code\myproject\venv\Lib\site-
packages\django\utils\functional.py", line 57, in __get__
res = instance.__dict__[self.name] = self.func(instance)
^^^^^^^^^^^^^^^^^^^
File "C:\code\myproject\venv\Lib\site-
packages\django\urls\resolvers.py", line 715, in url_patterns
patterns = getattr(self.urlconf_module, "urlpatterns",
self.urlconf_module)
^^^^^^^^^^^^^^^^^^^
File "C:\code\myproject\venv\Lib\site-
packages\django\utils\functional.py", line 57, in __get__
res = instance.__dict__[self.name] = self.func(instance)
^^^^^^^^^^^^^^^^^^^
File "C:\code\myproject\venv\Lib\site-
packages\django\urls\resolvers.py", line 708, in urlconf_module
return import_module(self.urlconf_name)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\Program Files\Python311\Lib\importlib\__init__.py", line 126,
in import_module
return _bootstrap._gcd_import(name[level:], package, level)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "<frozen importlib._bootstrap>", line 1206, in _gcd_import
File "<frozen importlib._bootstrap>", line 1178, in _find_and_load
File "<frozen importlib._bootstrap>", line 1149, in
_find_and_load_unlocked
File "<frozen importlib._bootstrap>", line 690, in _load_unlocked
File "<frozen importlib._bootstrap_external>", line 940, in exec_module
File "<frozen importlib._bootstrap>", line 241, in
_call_with_frames_removed
File "C:\code\myproject\myproject\urls.py", line 8, in <module>
path('test/', TestView.as_view()),
^^^^^^^^^^^^^^^^^^
File "C:\code\myproject\venv\Lib\site-
packages\django\views\generic\base.py", line 119, in as_view
if cls.view_is_async:
^^^^^^^^^^^^^^^^^
File "C:\code\myproject\venv\Lib\site-
packages\django\utils\functional.py", line 71, in __get__
return self.fget(cls)
^^^^^^^^^^^^^^
File "C:\code\myproject\venv\Lib\site-
packages\django\views\generic\base.py", line 73, in view_is_async
raise ImproperlyConfigured(
django.core.exceptions.ImproperlyConfigured: TestView HTTP handlers must
either be all sync or all async.

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
File "C:\code\myproject\venv\Lib\site-packages\asgiref\sync.py", line
486, in thread_handler
raise exc_info[1]
File "C:\code\myproject\venv\Lib\site-
packages\django\core\handlers\exception.py", line 43, in inner
response = await get_response(request)
^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\code\myproject\venv\Lib\site-
packages\django\utils\deprecation.py", line 152, in __acall__
response = response or await self.get_response(request)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\code\myproject\venv\Lib\site-
packages\django\core\handlers\exception.py", line 45, in inner
response = await sync_to_async(
^^^^^^^^^^^^^^^^^^^^
File "C:\code\myproject\venv\Lib\site-packages\asgiref\sync.py", line
448, in __call__
ret = await asyncio.wait_for(future, timeout=None)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\Program Files\Python311\Lib\asyncio\tasks.py", line 442, in
wait_for
return await fut
^^^^^^^^^
File "C:\Program Files\Python311\Lib\concurrent\futures\thread.py", line
58, in run
result = self.fn(*self.args, **self.kwargs)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\code\myproject\venv\Lib\site-packages\asgiref\sync.py", line
488, in thread_handler
return func(*args, **kwargs)
^^^^^^^^^^^^^^^^^^^^^
File "C:\code\myproject\venv\Lib\site-
packages\django\core\handlers\exception.py", line 141, in
response_for_exception
response = handle_uncaught_exception(
^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\code\myproject\venv\Lib\site-
packages\django\core\handlers\exception.py", line 182, in
handle_uncaught_exception
return debug.technical_500_response(request, *exc_info)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\code\myproject\venv\Lib\site-packages\django\views\debug.py",
line 66, in technical_500_response
html = reporter.get_traceback_html()
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\code\myproject\venv\Lib\site-packages\django\views\debug.py",
line 396, in get_traceback_html
c = Context(self.get_traceback_data(), use_l10n=False)
^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\code\myproject\venv\Lib\site-packages\django\views\debug.py",
line 381, in get_traceback_data
c["raising_view_name"] = get_caller(self.request)
^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\code\myproject\venv\Lib\site-packages\django\views\debug.py",
line 99, in get_caller
resolver_match = resolve(request.path)
^^^^^^^^^^^^^^^^^^^^^
File "C:\code\myproject\venv\Lib\site-packages\django\urls\base.py",
line 24, in resolve
return get_resolver(urlconf).resolve(path)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\code\myproject\venv\Lib\site-
packages\django\urls\resolvers.py", line 663, in resolve
for pattern in self.url_patterns:
^^^^^^^^^^^^^^^^^
File "C:\code\myproject\venv\Lib\site-
packages\django\utils\functional.py", line 57, in __get__
res = instance.__dict__[self.name] = self.func(instance)
^^^^^^^^^^^^^^^^^^^
File "C:\code\myproject\venv\Lib\site-
packages\django\urls\resolvers.py", line 715, in url_patterns
patterns = getattr(self.urlconf_module, "urlpatterns",
self.urlconf_module)
^^^^^^^^^^^^^^^^^^^
File "C:\code\myproject\venv\Lib\site-
packages\django\utils\functional.py", line 57, in __get__
res = instance.__dict__[self.name] = self.func(instance)
^^^^^^^^^^^^^^^^^^^
File "C:\code\myproject\venv\Lib\site-
packages\django\urls\resolvers.py", line 708, in urlconf_module
return import_module(self.urlconf_name)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\Program Files\Python311\Lib\importlib\__init__.py", line 126,
in import_module
return _bootstrap._gcd_import(name[level:], package, level)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "<frozen importlib._bootstrap>", line 1206, in _gcd_import
File "<frozen importlib._bootstrap>", line 1178, in _find_and_load
File "<frozen importlib._bootstrap>", line 1149, in
_find_and_load_unlocked
File "<frozen importlib._bootstrap>", line 690, in _load_unlocked
File "<frozen importlib._bootstrap_external>", line 940, in exec_module
File "<frozen importlib._bootstrap>", line 241, in
_call_with_frames_removed
File "C:\code\myproject\myproject\urls.py", line 8, in <module>
path('test/', TestView.as_view()),
^^^^^^^^^^^^^^^^^^
File "C:\code\myproject\venv\Lib\site-
packages\django\views\generic\base.py", line 119, in as_view
if cls.view_is_async:
^^^^^^^^^^^^^^^^^
File "C:\code\myproject\venv\Lib\site-
packages\django\utils\functional.py", line 71, in __get__
return self.fget(cls)
^^^^^^^^^^^^^^
File "C:\code\myproject\venv\Lib\site-
packages\django\views\generic\base.py", line 73, in view_is_async
raise ImproperlyConfigured(
django.core.exceptions.ImproperlyConfigured: TestView HTTP handlers must
either be all sync or all async.