async def test_takewhile_too_few_args():
"""Check that takewhile raises TypeError when too few args."""
with pytest.raises(TypeError):
await aitertools.anext(aitertools.takewhile())
with pytest.raises(TypeError):
await aitertools.anext(aitertools.takewhile(lambda x: x))
async def test_takewhile_too_many_args():
"""Check that takewhile raises TypeError when too many args."""
with pytest.raises(TypeError):
await aitertools.anext(aitertools.takewhile(bool, range(1), 'a'))
async def test_takewhile_empty_iterable():
"""Check that takewhile is empty when the iterable is empty."""
assert (await aitertools.alist(
aitertools.takewhile(lambda x: x < 5, ())
)) == []
async def test_takewhile_uses_predicate():
"""Check the takewhile happy path. Get values until predicate is False."""
assert (await aitertools.alist(
aitertools.takewhile(lambda x: x < 5, range(10))
)) == [x for x in range(10) if x < 5]