def var_operations(tmp_path_factory) -> Generator[AppHarness, None, None]:
    """Start VarOperations app at tmp_path via AppHarness.

    Args:
        tmp_path_factory: pytest tmp_path_factory fixture

    Yields:
        running AppHarness instance
    """
    with AppHarness.create(
        root=tmp_path_factory.mktemp("var_operations"),
        app_source=VarOperations,
    ) as harness:
        assert harness.app_instance is not None, "app is not running"
        yield harness
Start VarOperations app at tmp_path via AppHarness.

    Args:
        tmp_path_factory: pytest tmp_path_factory fixture

    Yields:
        running AppHarness instance
    
tests/integration/test_var_operations.py