Method undo

src/_pytest/monkeypatch.py:347–383

Undo previous changes. This call consumes the undo stack. Calling it a second time has no effect unless you do more monkeypatching after the undo call. There is generally no need to call `undo()`, since it is called automatically during tear-down. Note that

(self)

        os.chdir(path)

    def undo(self) -> None:
        """Undo previous changes.

        This call consumes the undo stack. Calling it a second time has no
        effect unless you do more monkeypatching after the undo call.

        There is generally no need to call `undo()`, since it is
        called automatically during tear-down.

        Note that the same `monkeypatch` fixture is used across a
        single test function invocation. If `monkeypatch` is used both by
        the test function itself and one of the test fixtures,
        calling `undo()` will undo all of the changes made in
        both functions.
        """
        for obj, name, value in reversed(self._setattr):
            if value is not notset:
                setattr(obj, name, value)
            else:
                delattr(obj, name)
        self._setattr[:] = []
        for dictionary, key, value in reversed(self._setitem):
            if value is notset:
                try:
                    del dictionary[key]
                except KeyError:
                    pass  # Was already deleted, so we have the desired state.
            else:
                dictionary[key] = value
        self._setitem[:] = []
        if self._savesyspath is not None:
            sys.path[:] = self._savesyspath
            self._savesyspath = None

        if self._cwd is not None:
            os.chdir(self._cwd)
            self._cwd = None