async def test_chain_non_iterables():
"""Check that chain raises TypeError if given non-iterable values."""
with pytest.raises(TypeError):
await aitertools.anext(aitertools.chain(1, 2))
async def test_chain_single_iterable():
"""Check if chain works when given only one iterable."""
assert (await aitertools.alist(
aitertools.chain('abc')
)) == list('abc')
async def test_chain_empty_iterable():
"""Check that chain result is empty if all iterables are empty."""
assert (await aitertools.alist(
aitertools.chain([])
)) == []
async def test_chain_combines_iterables():
"""Check that chain produces values from all iterables."""
assert (await aitertools.alist(
aitertools.chain('abc', 'def')
)) == list('abcdef')
