async def test_misuse_enter_context():
async with a.ExitStack() as exit_stack:
with pytest.raises(AttributeError):
await exit_stack.enter_context(None)
async with a.ExitStack() as exit_stack:
with pytest.raises(AttributeError) as exc_info:
try:
{}[1]
except KeyError:
await exit_stack.enter_context(None)
assert type(exc_info.value.__context__.__context__) is KeyError
async def test_exit_stack_pop_all():
async with a.ExitStack() as exit_stack:
contexts = list(
map(lambda v: MockAsyncContext(v) if v % 2 else MockContext(v),
range(10)))
values = await a.list(a.map(exit_stack.enter_context, contexts))
assert values == list(range(10))
assert all(cm.entered for cm in contexts)
assert all(not cm.exited for cm in contexts)
clone_stack = exit_stack.pop_all()
assert all(not cm.exited for cm in contexts)
await clone_stack.aclose()
assert all(cm.exited for cm in contexts)
async def test_exit_stack_callback():
"""Test that callbacks are run regardless of exceptions"""
unwind_values = []
async def push(value):
unwind_values.append(value)
return True # attempt to suppress - this must not succeed
with pytest.raises(KeyError):
async with a.ExitStack() as exit_stack:
for value in range(5):
exit_stack.callback(push, value)
raise KeyError()
assert unwind_values == list(reversed(range(5)))
async def test_exit_stack_push():
seen = []
@contextmanager
def observe():
try:
yield
except BaseException as exc_val:
seen.append(exc_val)
raise
@a.contextmanager
async def suppress():
try:
yield
except BaseException as exc_val:
seen.append(exc_val)
async def replace(exc_type, exc_val, tb, new):
seen.append(exc_val)
raise new
with pytest.raises(TypeError) as exc_info:
async with a.ExitStack() as exit_stack:
exit_stack.push(partial(replace, new=TypeError()))
exit_stack.push(partial(replace, new=ValueError()))
s = suppress()
await s.__aenter__()
exit_stack.push(s)
exit_stack.push(partial(replace, new=IndexError()))
o = observe()
o.__enter__()
exit_stack.push(o)
raise KeyError()
assert list(map(type, seen)) == [
KeyError,
KeyError,
IndexError,
type(None),
ValueError,
]
assert seen[2].__context__ == seen[1]
assert exc_info.type == TypeError
assert exc_info.value.__context__ == seen[-1]
async def test_exit_stack_stitch_context():
async def replace(exc_type, exc_val, tb, new):
try:
{}["a"]
except KeyError:
raise new
async def extend(exc_type, exc_val, tb, new):
try:
raise exc_val
except exc_type:
raise new
replacement_exc, middle_exc, initial_exc = TypeError(), ValueError(
), IndexError()
with pytest.raises(type(replacement_exc)) as exc_info:
async with a.ExitStack() as exit_stack:
exit_stack.push(partial(extend, new=replacement_exc))
exit_stack.push(partial(replace, new=middle_exc))
raise initial_exc
assert exc_info.value.__context__ == middle_exc
assert exc_info.value.__context__.__context__ == initial_exc
async def test_exist_stack():
async with a.ExitStack() as exit_stack:
for value in (0, 1, 2, 3, -5, None, "Hello"):
assert value == await exit_stack.enter_context(a.nullcontext(value)
)