This test checks that changing the grid-template-columns lead to a repaint. The final grid element should be 250px * 50px, the grid item should be 50px * 50px. No trace of the elements before the grid-template-columns change should be seen.
(repaint rects
  (rect 8 48 100 50)
  (rect 8 48 50 50)
  (rect 8 48 250 50)
)