Method test_invalid_cb_for_3bytes_seq

Lib/test/test_str.py:2106–2162

Test that an 'invalid continuation byte' error is raised when the continuation byte(s) of a 3-bytes sequence are invalid. When errors='replace', if the first continuation byte is valid, the first two bytes (start byte + 1st cb) are replaced by a single U+FFFD and th

(self)

                                           'invalid continuation byte')

    def test_invalid_cb_for_3bytes_seq(self):
        """
        Test that an 'invalid continuation byte' error is raised when the
        continuation byte(s) of a 3-bytes sequence are invalid.  When
        errors='replace', if the first continuation byte is valid, the first
        two bytes (start byte + 1st cb) are replaced by a single U+FFFD and the
        third byte is handled separately, otherwise only the start byte is
        replaced with a U+FFFD and the other continuation bytes are handled
        separately.
        E.g. in the sequence <E1 80 41>, E1 is the start byte of a 3-bytes
        sequence, 80 is a valid continuation byte, but 41 is not a valid cb
        because it's the ASCII letter 'A&#x27;.
        Note: when the start byte is E0 or ED, the valid ranges for the first
        continuation byte are limited to A0..BF and 80..9F respectively.
        Python 2 used to consider all the bytes in range 80..BF valid when the
        start byte was ED.  This is fixed in Python 3.
        """
        FFFD = '\ufffd'
        FFFDx2 = FFFD * 2
        sequences = [
            ('E0 00', FFFD+'\x00'), ('E0 7F', FFFD+'\x7f'), ('E0 80', FFFDx2),
            ('E0 9F', FFFDx2), ('E0 C0', FFFDx2), ('E0 FF', FFFDx2),
            ('E0 A0 00', FFFD+'\x00'), ('E0 A0 7F', FFFD+'\x7f'),
            ('E0 A0 C0', FFFDx2), ('E0 A0 FF', FFFDx2),
            ('E0 BF 00', FFFD+'\x00'), ('E0 BF 7F', FFFD+'\x7f'),
            ('E0 BF C0', FFFDx2), ('E0 BF FF', FFFDx2), ('E1 00', FFFD+'\x00'),
            ('E1 7F', FFFD+'\x7f'), ('E1 C0', FFFDx2), ('E1 FF', FFFDx2),
            ('E1 80 00', FFFD+'\x00'), ('E1 80 7F', FFFD+'\x7f'),
            ('E1 80 C0', FFFDx2), ('E1 80 FF', FFFDx2),
            ('E1 BF 00', FFFD+'\x00'), ('E1 BF 7F', FFFD+'\x7f'),
            ('E1 BF C0', FFFDx2), ('E1 BF FF', FFFDx2), ('EC 00', FFFD+'\x00'),
            ('EC 7F', FFFD+'\x7f'), ('EC C0', FFFDx2), ('EC FF', FFFDx2),
            ('EC 80 00', FFFD+'\x00'), ('EC 80 7F', FFFD+'\x7f'),
            ('EC 80 C0', FFFDx2), ('EC 80 FF', FFFDx2),
            ('EC BF 00', FFFD+'\x00'), ('EC BF 7F', FFFD+'\x7f'),
            ('EC BF C0', FFFDx2), ('EC BF FF', FFFDx2), ('ED 00', FFFD+'\x00'),
            ('ED 7F', FFFD+'\x7f'),
            ('ED A0', FFFDx2), ('ED BF', FFFDx2), # see note ^
            ('ED C0', FFFDx2), ('ED FF', FFFDx2), ('ED 80 00', FFFD+'\x00'),
            ('ED 80 7F', FFFD+'\x7f'), ('ED 80 C0', FFFDx2),
            ('ED 80 FF', FFFDx2), ('ED 9F 00', FFFD+'\x00'),
            ('ED 9F 7F', FFFD+'\x7f'), ('ED 9F C0', FFFDx2),
            ('ED 9F FF', FFFDx2), ('EE 00', FFFD+'\x00'),
            ('EE 7F', FFFD+'\x7f'), ('EE C0', FFFDx2), ('EE FF', FFFDx2),
            ('EE 80 00', FFFD+'\x00'), ('EE 80 7F', FFFD+'\x7f'),
            ('EE 80 C0', FFFDx2), ('EE 80 FF', FFFDx2),
            ('EE BF 00', FFFD+'\x00'), ('EE BF 7F', FFFD+'\x7f'),
            ('EE BF C0', FFFDx2), ('EE BF FF', FFFDx2), ('EF 00', FFFD+'\x00'),
            ('EF 7F', FFFD+'\x7f'), ('EF C0', FFFDx2), ('EF FF', FFFDx2),
            ('EF 80 00', FFFD+'\x00'), ('EF 80 7F', FFFD+'\x7f'),
            ('EF 80 C0', FFFDx2), ('EF 80 FF', FFFDx2),
            ('EF BF 00', FFFD+'\x00'), ('EF BF 7F', FFFD+'\x7f'),
            ('EF BF C0', FFFDx2), ('EF BF FF', FFFDx2),
        ]
        for seq, res in sequences:
            self.assertCorrectUTF8Decoding(bytes.fromhex(seq), res,
                                           'invalid continuation byte')