def it_returns_a_collecting_child_before_itself():
group = BaseGroup()
group.add_child(BaseGroup())
group.is_collecting = True
group.children[0].is_collecting = True
assert group.get_collecting_group() == group.children[0]
def it_returns_rightmost_collecting_child():
group = BaseGroup()
group.add_child(BaseGroup())
group.add_child(BaseGroup())
group.children[0].is_collecting = True
group.children[1].is_collecting = True
assert group.get_collecting_group() == group.children[1]
def it_adds_a_group_to_its_children_and_sets_parent():
group_a = BaseGroup()
group_b = BaseGroup()
group_a.add_child(group_b)
assert group_a.children == [group_b]
assert group_b.parent == group_a
