Function _file_extension

src/command_system/copy_command.py:139–145

TS ``fileExtension`` (copy.tsx:62-72) — sanitized to prevent path traversal.

(lang: str | None)

def _file_extension(lang: str | None) -> str:
    """TS ``fileExtension`` (copy.tsx:62-72) — sanitized to prevent path traversal."""
    if lang:
        sanitized = re.sub(r"[^a-zA-Z0-9]", "", lang)
        if sanitized and sanitized != "plaintext":
            return f".{sanitized}"
    return ".txt"


def _truncate_line(text: str, max_len: int) -> str: