@Test
public void testCustomViewConstants() {

  ViewManager mockViewManager = mock(ViewManager.class);
  List<ViewManager> viewManagers = Arrays.asList(mockViewManager);
  when(mockViewManager.getName()).thenReturn("RedPandaPhotoOfTheDayView");
  when(mockViewManager.getExportedViewConstants())
      .thenReturn(MapBuilder.of("PhotoSizeType", MapBuilder.of("Small", 1, "Large", 2)));
  UIManagerModule uiManagerModule =
      new UIManagerModule(mReactContext, viewManagers, mUIImplementationProvider, false, 0);
  Map<String, Object> constants = uiManagerModule.getConstants();
  assertThat(constants).containsKey("RedPandaPhotoOfTheDayView");
  assertThat((Map) constants.get("RedPandaPhotoOfTheDayView")).containsKey("Constants");
  assertThat((Map) valueAtPath(constants, "RedPandaPhotoOfTheDayView", "Constants"))
      .containsKey("PhotoSizeType");
}