tests.py 文件源码

def test_previous_status(self):
        from django.db.models.signals import post_save

        def check_different(sender, instance, **kwargs):
            check_different.is_different = (instance._status != instance.status)

        check_different.is_different = None

        post_save.connect(check_different)

        s = Service(name="service", description="test", status=0)
        s.save()
        self.assertFalse(check_different.is_different)
        s.status = 0
        s.save()
        self.assertFalse(check_different.is_different)
        s.status = 1
        s.save()
        self.assertIsNotNone(check_different.is_different)
        self.assertTrue(check_different.is_different)

        post_save.disconnect(check_different)