def test_revert_end(self):
history = UndoHistory()
self._populate_history(history)
with self.assertTraitChanges(history, 'redoable', count=2):
with self.assertTraitChanges(history, 'undoable', count=1):
with self.assertTraitChanges(self._example,
'anytrait',
count=3): # noqa: E501
history.revert()
self.assertEqual(history.now, 0)
self.assertFalse(history.can_undo)
self.assertFalse(history.can_redo)
def test_revert_start(self):
history = UndoHistory()
self._populate_history(history)
history.undo()
history.undo()
history.undo()
with self.assertTraitDoesNotChange(history, 'undoable'):
with self.assertTraitChanges(history, 'redoable', count=1):
with self.assertTraitDoesNotChange(self._example, 'anytrait'):
history.revert()
self.assertEqual(history.now, 0)
self.assertFalse(history.can_undo)
self.assertFalse(history.can_redo)