test_cached_tokenizer.py

# SPDX-License-Identifier: Apache-2.0
# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
import pickle
from copy import deepcopy

import pytest
from transformers import AutoTokenizer

from vllm.transformers_utils.tokenizer import AnyTokenizer, get_cached_tokenizer


@pytest.mark.parametrize("model_id", ["gpt2", "zai-org/chatglm3-6b"])
def test_cached_tokenizer(model_id: str):
    reference_tokenizer = AutoTokenizer.from_pretrained(
        model_id, trust_remote_code=True
    )
    reference_tokenizer.add_special_tokens({"cls_token": "<CLS>"})
    reference_tokenizer.add_special_tokens({"additional_special_tokens": ["<SEP>"]})

    cached_tokenizer = get_cached_tokenizer(deepcopy(reference_tokenizer))
    _check_consistency(cached_tokenizer, reference_tokenizer)

    pickled_tokenizer = pickle.dumps(cached_tokenizer)
    unpickled_tokenizer = pickle.loads(pickled_tokenizer)
    _check_consistency(unpickled_tokenizer, reference_tokenizer)


def _check_consistency(target: AnyTokenizer, expected: AnyTokenizer):
    assert isinstance(target, type(expected))

    # Cached attributes
    assert target.all_special_ids == expected.all_special_ids
    assert target.all_special_tokens == expected.all_special_tokens
    assert target.get_vocab() == expected.get_vocab()
    assert len(target) == len(expected)

    # Other attributes
    assert getattr(target, "padding_side", None) == getattr(
        expected, "padding_side", None
    )

    assert target.encode("prompt") == expected.encode("prompt")