def test_migrate(self, path_exists, mkdir, shutil):
unit_id = '123'
plan = Mock()
path = '/tmp/old/path_1'
new_path = '/tmp/new/content/path_2'
path_exists.return_value = True
# test
Unit.migrate(plan, unit_id, path, new_path)
# validation
path_exists.assert_called_once_with(path)
mkdir.assert_called_once_with(os.path.dirname(new_path))
shutil.move.assert_called_once_with(path, new_path)
plan.collection.update_one.assert_called_once_with(
filter={'_id': unit_id},
update={'$set': {'_storage_path': new_path}})
