import pytest

from spacy.tokens import Doc, Token
from spacy.vocab import Vocab


@pytest.fixture
def doc_w_attrs(en_tokenizer):
    Doc.set_extension("_test_attr", default=False)
    Doc.set_extension("_test_prop", getter=lambda doc: len(doc.text))
    Doc.set_extension("_test_method", method=lambda doc, arg: f"{len(doc.text)}{arg}")
    doc = en_tokenizer("This is a test.")
    doc._._test_attr = "test"

    Token.set_extension("_test_token", default="t0")
    doc[1]._._test_token = "t1"

    return doc


def test_serialize_ext_attrs_from_bytes(doc_w_attrs):
    doc_b = doc_w_attrs.to_bytes()
    doc = Doc(Vocab()).from_bytes(doc_b)
    assert doc._.has("_test_attr")
    assert doc._._test_attr == "test"
    assert doc._._test_prop == len(doc.text)
    assert doc._._test_method("test") == f"{len(doc.text)}test"
    assert doc[0]._._test_token == "t0"
    assert doc[1]._._test_token == "t1"
    assert doc[2]._._test_token == "t0"
