Class override_settings

django/test/utils.py:483–565

Act as either a decorator or a context manager. If it's a decorator, take a function and return a wrapped function. If it's a contextmanager, use it with the ``with`` statement. In either event, entering/exiting are called before and after, respectively, the function/block is execut

class override_settings(TestContextDecorator):
    """
    Act as either a decorator or a context manager. If it's a decorator, take a
    function and return a wrapped function. If it's a contextmanager, use it
    with the ``with`` statement. In either event, entering/exiting are called
    before and after, respectively, the function/block is executed.
    """

    enable_exception = None

    def __init__(self, **kwargs):
        self.options = kwargs
        super().__init__()

    def enable(self):
        # Keep this code at the beginning to leave the settings unchanged
        # in case it raises an exception because INSTALLED_APPS is invalid.
        if "INSTALLED_APPS" in self.options:
            try:
                apps.set_installed_apps(self.options["INSTALLED_APPS"])
            except Exception:
                apps.unset_installed_apps()
                raise
        override = UserSettingsHolder(settings._wrapped)
        for key, new_value in self.options.items():
            setattr(override, key, new_value)
        self.wrapped = settings._wrapped
        settings._wrapped = override
        for key, new_value in self.options.items():
            try:
                setting_changed.send(
                    sender=settings._wrapped.__class__,
                    setting=key,
                    value=new_value,
                    enter=True,
                )
            except Exception as exc:
                self.enable_exception = exc
                self.disable()

    def disable(self):
        if "INSTALLED_APPS" in self.options:
            apps.unset_installed_apps()
        settings._wrapped = self.wrapped
        del self.wrapped
        responses = []
        for key in self.options:
            new_value = getattr(settings, key, None)
            responses_for_setting = setting_changed.send_robust(
                sender=settings._wrapped.__class__,
                setting=key,
                value=new_value,
                enter=False,
            )
            responses.extend(responses_for_setting)
        if self.enable_exception is not None:
            exc = self.enable_exception
            self.enable_exception = None