from gcode.windows import decode_bytes, truncate_output


def test_decode_utf8() -> None:
    assert decode_bytes("你好".encode("utf-8")) == "你好"


def test_decode_gbk_fallback() -> None:
    assert decode_bytes("你好".encode("gbk")) == "你好"


def test_decode_empty() -> None:
    assert decode_bytes(b"") == ""


def test_truncate() -> None:
    text = "a" * 100
    assert truncate_output(text, limit=50).endswith("字符]")
    assert "a" * 20 == truncate_output("a" * 20, limit=50)