def test_invalid_scalar_index(adata, index):
    # https://github.com/theislab/anndata/issues/619
    with pytest.raises(IndexError, match=r".*index.* out of range\."):
        _ = adata[index]
def test_regex_bad_pattern():
    """Regex error raised immediately when regex input parser is created."""
    assert_raises(re.error, inputs.regex, '[')