def test_add__add_undo_redo(self):
grid = Grid(5)
grid.add_black_cell(1, 2)
grid.add_black_cell(3, 4)
self.assertEqual(True, grid.is_black_cell(1, 2))
self.assertEqual(True, grid.is_black_cell(5, 4))
self.assertEqual(True, grid.is_black_cell(3, 4))
self.assertEqual(True, grid.is_black_cell(3, 2))
self.assertEqual([(1, 2), (3, 4)], grid.undo_stack)
self.assertEqual([], grid.redo_stack)
grid.undo()
self.assertEqual(True, grid.is_black_cell(1, 2))
self.assertEqual(True, grid.is_black_cell(5, 4))
self.assertEqual(False, grid.is_black_cell(3, 4))
self.assertEqual(False, grid.is_black_cell(3, 2))
self.assertEqual([(1, 2)], grid.undo_stack)
self.assertEqual([(3, 4)], grid.redo_stack)
grid.redo()
self.assertEqual(True, grid.is_black_cell(1, 2))
self.assertEqual(True, grid.is_black_cell(5, 4))
self.assertEqual(True, grid.is_black_cell(3, 4))
self.assertEqual(True, grid.is_black_cell(3, 2))
self.assertEqual([(1, 2), (3, 4)], grid.undo_stack)
self.assertEqual([], grid.redo_stack)
grid.undo()
self.assertEqual(True, grid.is_black_cell(1, 2))
self.assertEqual(True, grid.is_black_cell(5, 4))
self.assertEqual(False, grid.is_black_cell(3, 4))
self.assertEqual(False, grid.is_black_cell(3, 2))
self.assertEqual([(1, 2)], grid.undo_stack)
self.assertEqual([(3, 4)], grid.redo_stack)
grid.undo()
self.assertEqual(False, grid.is_black_cell(1, 2))
self.assertEqual(False, grid.is_black_cell(5, 4))
self.assertEqual(False, grid.is_black_cell(3, 4))
self.assertEqual(False, grid.is_black_cell(3, 2))
self.assertEqual([], grid.undo_stack)
self.assertEqual([(3, 4), (1, 2)], grid.redo_stack)
def test_redo_with_empty_stack(self):
grid = Grid(5)
grid.redo()
self.assertListEqual([], grid.undo_stack)
self.assertListEqual([], grid.redo_stack)
pass
