from manim import RIGHT, UP, LinearTransformationScene, Vector, VGroup __module_test__ = "vector_space_scene" def test_ghost_vectors_len_and_types(): scene = LinearTransformationScene() scene.leave_ghost_vectors = True # prepare vectors (they require a vmobject as their target) v1, v2 = Vector(RIGHT), Vector(RIGHT) v1.target, v2.target = Vector(UP), Vector(UP) # ghost_vector addition is in this method scene.get_piece_movement((v1, v2)) ghosts = scene.get_ghost_vectors() assert len(ghosts) == 1 # check if there are two vectors in the ghost vector VGroup assert len(ghosts[0]) == 2 # check types of ghost vectors assert isinstance(ghosts, VGroup) assert isinstance(ghosts[0], VGroup) assert all(isinstance(x, Vector) for x in ghosts[0])