test_transform.py

from __future__ import annotations

from manim import Circle, ReplacementTransform, Scene, Square, VGroup


def test_no_duplicate_references():
    scene = Scene()
    c = Circle()
    sq = Square()
    scene.add(c, sq)

    scene.play(ReplacementTransform(c, sq))
    assert len(scene.mobjects) == 1
    assert scene.mobjects[0] is sq


def test_duplicate_references_in_group():
    scene = Scene()
    c = Circle()
    sq = Square()
    vg = VGroup(c, sq)
    scene.add(vg)

    scene.play(ReplacementTransform(c, sq))
    submobs = vg.submobjects
    assert len(submobs) == 1
    assert submobs[0] is sq