class TestDataCheckpoint(unittest.TestCase): def setUp(self): self._checkpoint = DataCheckpoint() def test_operator_bool_false_on_init(self): self.assertFalse(self._checkpoint) def test_operator_bool_true_with_data(self): self._checkpoint.replace('abc') self.assertTrue(self._checkpoint) def test_replace(self): self._checkpoint.replace('abc') self.assertEqual(self._checkpoint.data, 'abc') self._checkpoint.replace('def') self.assertEqual(self._checkpoint.data, 'def') def test_append(self): self._checkpoint.append('abc') self.assertEqual(self._checkpoint.data, 'abc') self._checkpoint.append('def') self.assertEqual(self._checkpoint.data, 'abcdef') def test_clear(self): self._checkpoint.append('abc') self.assertEqual(self._checkpoint.data, 'abc') self._checkpoint.clear() self.assertEqual(self._checkpoint.data, None)