import random

import pytest

from framing import FrameDecoder, encode


def test_any_split_restores_messages():
    msgs = [{"seq": i, "text": "你好" * i} for i in range(20)]
    stream = b"".join(encode(m) for m in msgs)
    rng = random.Random(42)
    for _ in range(100):                                  # 随机切分 100 种方式
        dec, out, i = FrameDecoder(), [], 0
        while i < len(stream):
            j = i + rng.randint(1, 17)
            out += dec.feed(stream[i:j])
            i = j
        assert out == msgs


def test_rejects_oversized_frame():
    with pytest.raises(ValueError):
        FrameDecoder(max_frame=10).feed(encode({"text": "x" * 100}))