def test_check_bytes(tmpdir): with io.open(os.path.join(str(tmpdir), 'test.asdf'), 'w', encoding='utf-8') as fd: assert generic_io._check_bytes(fd, 'r') is False assert generic_io._check_bytes(fd, 'rw') is False assert generic_io._check_bytes(fd, 'w') is False with io.open(os.path.join(str(tmpdir), 'test.asdf'), 'wb') as fd: assert generic_io._check_bytes(fd, 'r') is True assert generic_io._check_bytes(fd, 'rw') is True assert generic_io._check_bytes(fd, 'w') is True