Closes #15621: User notifications (#16800)

* Initial work on #15621

* Signal receiver should ignore models which don't support notifications

* Flesh out NotificationGroup functionality

* Add NotificationGroup filters for users & groups

* Separate read & dimiss actions

* Enable one-click dismissals from notifications list

* Include total notification count in dropdown

* Drop 'kind' field from Notification model

* Register event types in the registry; add colors & icons

* Enable event rules to target notification groups

* Define dynamic choices for Notification.event_name

* Move event registration to core

* Add more job events

* Misc cleanup

* Misc cleanup

* Correct absolute URLs for notifications & subscriptions

* Optimize subscriber notifications

* Use core event types when queuing events

* Standardize queued event attribute to event_type; change content_type to object_type

* Rename Notification.event_name to event_type

* Restore NotificationGroupBulkEditView

* Add API tests

* Add view & filterset tests

* Add model documentation

* Fix tests

* Update notification bell when notifications have been cleared

* Ensure subscribe button appears only on relevant models

* Notifications/subscriptions cannot be ordered by object

* Misc cleanup

* Add event icon & type to notifications table

* Adjust icon sizing

* Mute color of read notifications

* Misc cleanup

netbox/extras/tests/test_views.py

@@ -1,4 +1,3 @@
-from django.contrib.auth import get_user_model
 from django.contrib.contenttypes.models import ContentType
 from django.urls import reverse
 
@@ -6,10 +5,9 @@ from core.models import ObjectType
 from dcim.models import DeviceType, Manufacturer, Site
 from extras.choices import *
 from extras.models import *
+from users.models import Group, User
 from utilities.testing import ViewTestCases, TestCase
 
-User = get_user_model()
-
 
 class CustomFieldTestCase(ViewTestCases.PrimaryObjectViewTestCase):
     model = CustomField
@@ -620,3 +618,166 @@ class CustomLinkTest(TestCase):
         response = self.client.get(site.get_absolute_url(), follow=True)
         self.assertEqual(response.status_code, 200)
         self.assertIn(f'FOO {site.name} BAR', str(response.content))
+
+
+class SubscriptionTestCase(
+    ViewTestCases.CreateObjectViewTestCase,
+    ViewTestCases.DeleteObjectViewTestCase,
+    ViewTestCases.ListObjectsViewTestCase,
+    ViewTestCases.BulkDeleteObjectsViewTestCase
+):
+    model = Subscription
+
+    @classmethod
+    def setUpTestData(cls):
+        site_ct = ContentType.objects.get_for_model(Site)
+        sites = (
+            Site(name='Site 1', slug='site-1'),
+            Site(name='Site 2', slug='site-2'),
+            Site(name='Site 3', slug='site-3'),
+            Site(name='Site 4', slug='site-4'),
+        )
+        Site.objects.bulk_create(sites)
+
+        cls.form_data = {
+            'object_type': site_ct.pk,
+            'object_id': sites[3].pk,
+        }
+
+    def setUp(self):
+        super().setUp()
+
+        sites = Site.objects.all()
+        user = self.user
+
+        subscriptions = (
+            Subscription(object=sites[0], user=user),
+            Subscription(object=sites[1], user=user),
+            Subscription(object=sites[2], user=user),
+        )
+        Subscription.objects.bulk_create(subscriptions)
+
+    def _get_url(self, action, instance=None):
+        if action == 'list':
+            return reverse('account:subscriptions')
+        return super()._get_url(action, instance)
+
+    def test_list_objects_anonymous(self):
+        self.client.logout()
+        url = reverse('account:subscriptions')
+        login_url = reverse('login')
+        self.assertRedirects(self.client.get(url), f'{login_url}?next={url}')
+
+    def test_list_objects_with_permission(self):
+        return
+
+    def test_list_objects_with_constrained_permission(self):
+        return
+
+
+class NotificationGroupTestCase(ViewTestCases.PrimaryObjectViewTestCase):
+    model = NotificationGroup
+
+    @classmethod
+    def setUpTestData(cls):
+        users = (
+            User(username='User 1'),
+            User(username='User 2'),
+            User(username='User 3'),
+        )
+        User.objects.bulk_create(users)
+        groups = (
+            Group(name='Group 1'),
+            Group(name='Group 2'),
+            Group(name='Group 3'),
+        )
+        Group.objects.bulk_create(groups)
+
+        notification_groups = (
+            NotificationGroup(name='Notification Group 1'),
+            NotificationGroup(name='Notification Group 2'),
+            NotificationGroup(name='Notification Group 3'),
+        )
+        NotificationGroup.objects.bulk_create(notification_groups)
+        for i, notification_group in enumerate(notification_groups):
+            notification_group.users.add(users[i])
+            notification_group.groups.add(groups[i])
+
+        cls.form_data = {
+            'name': 'Notification Group X',
+            'description': 'Blah',
+            'users': [users[0].pk, users[1].pk],
+            'groups': [groups[0].pk, groups[1].pk],
+        }
+
+        cls.csv_data = (
+            'name,description,users,groups',
+            'Notification Group 4,Foo,"User 1,User 2","Group 1,Group 2"',
+            'Notification Group 5,Bar,"User 1,User 2","Group 1,Group 2"',
+            'Notification Group 6,Baz,"User 1,User 2","Group 1,Group 2"',
+        )
+
+        cls.csv_update_data = (
+            "id,name",
+            f"{notification_groups[0].pk},Notification Group 7",
+            f"{notification_groups[1].pk},Notification Group 8",
+            f"{notification_groups[2].pk},Notification Group 9",
+        )
+
+        cls.bulk_edit_data = {
+            'description': 'New description',
+        }
+
+
+class NotificationTestCase(
+    ViewTestCases.DeleteObjectViewTestCase,
+    ViewTestCases.ListObjectsViewTestCase,
+    ViewTestCases.BulkDeleteObjectsViewTestCase
+):
+    model = Notification
+
+    @classmethod
+    def setUpTestData(cls):
+        site_ct = ContentType.objects.get_for_model(Site)
+        sites = (
+            Site(name='Site 1', slug='site-1'),
+            Site(name='Site 2', slug='site-2'),
+            Site(name='Site 3', slug='site-3'),
+            Site(name='Site 4', slug='site-4'),
+        )
+        Site.objects.bulk_create(sites)
+
+        cls.form_data = {
+            'object_type': site_ct.pk,
+            'object_id': sites[3].pk,
+        }
+
+    def setUp(self):
+        super().setUp()
+
+        sites = Site.objects.all()
+        user = self.user
+
+        notifications = (
+            Notification(object=sites[0], user=user),
+            Notification(object=sites[1], user=user),
+            Notification(object=sites[2], user=user),
+        )
+        Notification.objects.bulk_create(notifications)
+
+    def _get_url(self, action, instance=None):
+        if action == 'list':
+            return reverse('account:notifications')
+        return super()._get_url(action, instance)
+
+    def test_list_objects_anonymous(self):
+        self.client.logout()
+        url = reverse('account:notifications')
+        login_url = reverse('login')
+        self.assertRedirects(self.client.get(url), f'{login_url}?next={url}')
+
+    def test_list_objects_with_permission(self):
+        return
+
+    def test_list_objects_with_constrained_permission(self):
+        return