check_panel_invalid_group_raises¶

def check_panel_invalid_group_raises(forecaster, y_panel: pl.DataFrame) -> None:
    """Check that an invalid group name raises ValueError.

    Validates error handling when ``groups`` specifies group names that
    were not seen during fit.

    Parameters
    ----------
    forecaster : BaseForecaster
        Fitted forecaster with panel data
    y_panel : pl.DataFrame
        Panel data with panel columns for testing

    Raises
    ------
    AssertionError
        If ValueError is not raised for invalid group

    """
    _, y_panel_groups = inspect_panel(y_panel)

    if len(y_panel_groups) > 0:
        # Try to predict with invalid group name
        try:
            _call_predict(forecaster, forecasting_horizon=3, groups=["invalid_group"])
            raise AssertionError("predict() should raise ValueError for an invalid group name, but didn't")
        except ValueError as e:
            # Expected - the message must name the offending group so callers can act on it.
            assert "invalid_group" in str(e), f"ValueError should name the invalid group in the message, got: {e}"