added assertiions for graphical_units

Author: Hugues Devimeux

tests/helpers/graphical_units.py

@@ -5,7 +5,6 @@
 import tempfile
 import numpy as np
 
-import manim
 from manim import config, file_writer_config, logger
 
 
@@ -43,11 +42,14 @@ def set_test_scene(scene_object, module_name):
         scene.render()
         data = scene.renderer.get_frame()
 
+    assert not np.all(
+        data == np.array([0, 0, 0, 255])
+    ), f"Control data generated for {str(scene)} only contains empty pixels."
+    assert data.shape == (480, 854, 4)
     tests_directory = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
     path_control_data = os.path.join(
         tests_directory, "control_data", "graphical_units_data"
     )
-    print(path_control_data)
     path = os.path.join(path_control_data, module_name)
     if not os.path.isdir(path):
         os.makedirs(path)