@mock.patch('sys.exit')
    def test_bad_format_string(self, fake_exit):
        previous_format = TAPTestResult.FORMAT
        bad_format = "Not gonna work {sort_desc}"
        TAPTestRunner.set_format(bad_format)
        result = TAPTestResult(None, True, 1)
        test = mock.Mock()

        result._description(test)

        self.assertTrue(fake_exit.called)

        TAPTestResult.FORMAT = previous_format
Verify the done queryset.
dataset/ETHPy150Open mblayman/tappy/tap/tests/test_runner.py/TestTAPTestRunner.test_bad_format_string--crossover with--dataset/ETHPy150Open mozilla/kitsune/kitsune/questions/tests/test_managers.py/QuestionManagerTestCase.test_done