import pytest from tox.pytest import ToxProjectCreator @pytest.mark.plugin_test() def test_inline_tox_py(tox_project: ToxProjectCreator) -> None: ini = """ from tox.plugin import impl @impl def tox_add_option(parser): parser.add_argument("--magic", action="store_true") """ project = tox_project({"toxfile.py": ini}) result = project.run("-h") result.assert_success() assert "--magic" in result.out