import pytest

from siebenapp.tests.dsl import build_goaltree, open_


def test_two_parents_for_one_goal_is_forbidden() -> None:
    with pytest.raises(AssertionError):
        build_goaltree(
            open_(1, "First parent of 3", [2, 3]),
            open_(2, "Second parent of 3", [3]),
            open_(3, "Fellow child"),
        )
