async generator missing unawaited coroutine warning

[graingert]

BPO	44928
Nosy	@graingert

^{Note: these values reflect the state of the issue at the time it was migrated and might not reflect the current state.}

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GitHub fields:

assignee = None
closed_at = None
created_at = <Date 2021-08-16.21:29:12.364>
labels = ['interpreter-core', '3.8', '3.9', '3.10', '3.11', '3.7']
title = 'async generator missing unawaited coroutine warning'
updated_at = <Date 2021-08-16.21:29:12.364>
user = 'https://github.com/graingert'

bugs.python.org fields:

activity = <Date 2021-08-16.21:29:12.364>
actor = 'graingert'
assignee = 'none'
closed = False
closed_date = None
closer = None
components = ['Interpreter Core']
creation = <Date 2021-08-16.21:29:12.364>
creator = 'graingert'
dependencies = []
files = []
hgrepos = []
issue_num = 44928
keywords = []
message_count = 1.0
messages = ['399684']
nosy_count = 1.0
nosy_names = ['graingert']
pr_nums = []
priority = 'normal'
resolution = None
stage = None
status = 'open'
superseder = None
type = None
url = 'https://bugs.python.org/issue44928'
versions = ['Python 3.6', 'Python 3.7', 'Python 3.8', 'Python 3.9', 'Python 3.10', 'Python 3.11']

Linked PRs

• GH-89091: raise RuntimeWarning for unawaited async generator methods #104611

[graingert]

demo program:

def test_async_fn():
    async def async_fn():
        pass

    async_fn()  # Missing 'await'; produces RuntimeWarning


def test_async_gen_fn():
    async def agen_fn():
        yield

    agen_fn().aclose()  # Missing 'await' but no warning
    agen_fn().asend(None)  # Missing 'await' but no warning

test_async_fn()  # Warning
test_async_gen_fn()  # No warnings

output:

/home/graingert/projects/anyio/foo.py:5: RuntimeWarning: coroutine 'test_async_fn.<locals>.async_fn' was never awaited
  async_fn()
RuntimeWarning: Enable tracemalloc to get the object allocation traceback

expected:

/home/graingert/projects/anyio/foo.py:5: RuntimeWarning: coroutine 'test_async_fn.<locals>.async_fn' was never awaited
  async_fn()
RuntimeWarning: Enable tracemalloc to get the object allocation traceback
/home/graingert/projects/anyio/foo.py:12: RuntimeWarning: coroutine '<async_generator_athrow object at 0xffffffffffff>' was never awaited
  agen_fn().aclose()
RuntimeWarning: Enable tracemalloc to get the object allocation traceback
/home/graingert/projects/anyio/foo.py:13: RuntimeWarning: coroutine '<async_generator_asend object at 0xffffffffffff>' was never awaited
  agen_fn().asend(None)
RuntimeWarning: Enable tracemalloc to get the object allocation traceback