Refs #18100 -- Added tests for deferred model deletion signals.

from django.contrib.contenttypes.models import ContentType

from django.contrib.sessions.backends.db import SessionStore

from django.db import models

from django.db.models import Count

from django.test import TestCase, override_settings

                 .defer('request1', 'request2', 'request3', 'request4')),

            list

        )

class DeferDeletionSignalsTests(TestCase):

    senders = [Item, Proxy]

    @classmethod

    def setUpTestData(cls):

        cls.item_pk = Item.objects.create(value=1).pk

    def setUp(self):

        self.pre_delete_senders = []

        self.post_delete_senders = []

        for sender in self.senders:

            models.signals.pre_delete.connect(self.pre_delete_receiver, sender)

            models.signals.post_delete.connect(self.post_delete_receiver, sender)

    def tearDown(self):

        for sender in self.senders:

            models.signals.pre_delete.disconnect(self.pre_delete_receiver, sender)

            models.signals.post_delete.disconnect(self.post_delete_receiver, sender)

    def pre_delete_receiver(self, sender, **kwargs):

        self.pre_delete_senders.append(sender)

    def post_delete_receiver(self, sender, **kwargs):

        self.post_delete_senders.append(sender)

    def test_delete_defered_model(self):

        Item.objects.only('value').get(pk=self.item_pk).delete()

        self.assertEqual(self.pre_delete_senders, [Item])

        self.assertEqual(self.post_delete_senders, [Item])

    def test_delete_defered_proxy_model(self):

        Proxy.objects.only('value').get(pk=self.item_pk).delete()

        self.assertEqual(self.pre_delete_senders, [Proxy])

        self.assertEqual(self.post_delete_senders, [Proxy])