Method _test_truncated_data

Lib/test/pickletester.py:1108–1131

(self, dumped, expected_error=None)

            self.assertEqual(self.loads(data(idx)), ([],)*2)

    def _test_truncated_data(self, dumped, expected_error=None):
        # Test that instructions to read large data without providing
        # such amount of data do not cause large memory usage.
        if expected_error is None:
            expected_error = self.truncated_data_error
        # BytesIO
        with self.assertRaisesRegex(*expected_error):
            self.loads(dumped)
        if hasattr(self, 'unpickler'):
            try:
                with open(TESTFN, 'wb') as f:
                    f.write(dumped)
                # buffered file
                with open(TESTFN, 'rb') as f:
                    u = self.unpickler(f)
                    with self.assertRaisesRegex(*expected_error):
                        u.load()
                # unbuffered file
                with open(TESTFN, 'rb', buffering=0) as f:
                    u = self.unpickler(f)
                    with self.assertRaisesRegex(*expected_error):
                        u.load()
            finally:
                os_helper.unlink(TESTFN)

    def test_truncated_large_binstring(self):
        data = lambda size: b'T' + struct.pack('<I', size) + b'.' * 5