def test_vmobject_same_points_become():
a = Square()
b = Circle()
a.become(b)
np.testing.assert_array_equal(a.points, b.points)
assert len(a.submobjects) == len(b.submobjects)
def test_shift_family():
"""Check that each member of the family is shifted along with the parent.
Importantly, here we add a common grandchild to each of the children. So
this test will fail if the grandchild moves twice as much as it should.
"""
# Note shift() needs the mobject to have a non-empty `points` attribute, so
# we cannot use a plain Mobject or VMobject. We use Circle instead.
mob, child1, child2, = Circle(), Circle(), Circle(),
gchild1, gchild2, gchild_common = Circle(), Circle(), Circle()
child1.add(gchild1, gchild_common)
child2.add(gchild2, gchild_common)
mob.add(child1, child2)
family = mob.get_family()
positions_before = {m: m.get_center() for m in family}
mob.shift(RIGHT)
positions_after = {m: m.get_center() for m in family}
for m in family:
assert np.allclose(positions_before[m] + RIGHT, positions_after[m])