Hacked By AnonymousFox

"""
Helpers for working with Zope and its components.
"""
import atexit
import warnings
from typing import Set

from zope.component import getSiteManager
from zope.interface.registry import Components


class TestComponents:
    """
    A helper for providing a sterile registry when testing
    with ``zope.component``.

    Instantiation will install an empty registry that will be returned
    by :func:`zope.component.getSiteManager`.
    """
    __test__: bool = False

    instances: Set['TestComponents'] = set()
    atexit_setup: bool = False

    def __init__(self):
        self.registry: Components = Components('Testing')
        self.old: Components = getSiteManager.sethook(lambda: self.registry)
        self.instances.add(self)
        if not self.__class__.atexit_setup:
            atexit.register(self.atexit)
            self.__class__.atexit_setup = True

    def uninstall(self):
        """
        Remove the sterile registry and replace it with the one that
        was in place before this :class:`TestComponents` was
        instantiated.
        """
        getSiteManager.sethook(self.old)
        self.instances.remove(self)

    @classmethod
    def atexit(cls):
        if cls.instances:
            warnings.warn(
                'TestComponents instances not uninstalled by shutdown!'
                )