Method test_as_prefix

Lib/test/test_zstd.py:1488–1517

(self)

                              concatenation, tuple(correct_size_lst), 300*_1K, 5)

    def test_as_prefix(self):
        # V1
        V1 = THIS_FILE_BYTES
        zd = ZstdDict(V1, is_raw=True)

        # V2
        mid = len(V1) // 2
        V2 = V1[:mid] + \
             (b'a' if V1[mid] != int.from_bytes(b'a') else b'b') + \
             V1[mid+1:]

        # compress
        dat = compress(V2, zstd_dict=zd.as_prefix)
        self.assertEqual(get_frame_info(dat).dictionary_id, 0)

        # decompress
        self.assertEqual(decompress(dat, zd.as_prefix), V2)

        # use wrong prefix
        zd2 = ZstdDict(SAMPLES[0], is_raw=True)
        try:
            decompressed = decompress(dat, zd2.as_prefix)
        except ZstdError: # expected
            pass
        else:
            self.assertNotEqual(decompressed, V2)

        # read only attribute
        with self.assertRaises(AttributeError):
            zd.as_prefix = b'1234'

    def test_as_digested_dict(self):
        zd = TRAINED_DICT