Review-Labor: finde die versteckten Clipboard-Fehler

clipboard_exercise.pyAusschnitt

"""Intentionally faulty review exercise. Never use as a real clipboard adapter."""
from dataclasses import dataclass
from typing import Callable, Protocol

@dataclass(frozen=True)
class Snapshot:
    value: str | None
    revision: int

class Clipboard(Protocol):
    def read(self) -> Snapshot: ...
    def write(self, value: str | None) -> int: ...
    def compare_and_set(self, revision: int, value: str | None) -> bool: ...

def paste_text(clipboard: Clipboard, text: str, paste: Callable[[], None]) -> None:
    try:
        clipboard.write(text.strip())
        old = clipboard.read()