def test_remove_child():
animal = Category(name='animal')
cat = Category(name='cat')
cat._parent = animal
dog = Category(name='dog')
dog._parent = animal
animal._children = [cat, dog]
animal._remove_child(cat)
assert animal._children == [dog]
assert cat.parent is None
def test_add_parent():
# add on top of root
animal = Category(name='animal')
cat = Category(name='cat')
cat._add_parent(animal)
assert cat.parent is animal
assert animal.children == [cat]
# add instead of previous parent
animal = Category(name='animal')
lion = Category(name='lion')
animal._children = [lion]
lion._parent = animal
cat = Category(name='cat')
lion._add_parent(cat)
assert lion.parent is cat
assert cat.children == [lion]
assert animal.children == [cat]
def test_get_parent():
animal = Category(name='animal')
cat = Category(name='cat')
cat._parent = animal
assert cat.parent == animal