Method assertCorrectUTF8Decoding

Lib/test/test_str.py:2026–2043

Check that an invalid UTF-8 sequence raises a UnicodeDecodeError when 'strict' is used, returns res when 'replace' is used, and that doesn't return anything when 'ignore' is used.

(self, seq, res, err)

                             res.replace('\uFFFD', ''))

    def assertCorrectUTF8Decoding(self, seq, res, err):
        """
        Check that an invalid UTF-8 sequence raises a UnicodeDecodeError when
        'strict' is used, returns res when 'replace' is used, and that doesn't
        return anything when 'ignore' is used.
        """
        with self.assertRaises(UnicodeDecodeError) as cm:
            seq.decode('utf-8')
        exc = cm.exception

        self.assertIn(err, str(exc))
        self.assertEqual(seq.decode('utf-8', 'replace'), res)
        self.assertEqual((b'aaaa' + seq + b'bbbb').decode('utf-8', 'replace'),
                         'aaaa' + res + 'bbbb')
        res = res.replace('\ufffd', '')
        self.assertEqual(seq.decode('utf-8', 'ignore'), res)
        self.assertEqual((b'aaaa' + seq + b'bbbb').decode('utf-8', 'ignore'),
                          'aaaa' + res + 'bbbb')

    def test_invalid_start_byte(self):
        """