audit_log: Log RealmAuditLog for realm notification properties.

Log RealmAuditLog for do_set_realm_notifications_stream and
do_set_realm_signup_notifications_stream function.
Added tests for the same.

zerver/lib/actions.py

@@ -772,9 +772,20 @@ def do_set_realm_message_editing(realm: Realm,
     )
     send_event(realm, event, active_user_ids(realm.id))
 
-def do_set_realm_notifications_stream(realm: Realm, stream: Optional[Stream], stream_id: int) -> None:
+def do_set_realm_notifications_stream(realm: Realm, stream: Optional[Stream], stream_id: int,
+                                      acting_user: Optional[UserProfile]=None) -> None:
+    old_value = getattr(realm, 'notifications_stream')
     realm.notifications_stream = stream
     realm.save(update_fields=['notifications_stream'])
+
+    event_time = timezone_now()
+    RealmAuditLog.objects.create(
+        realm=realm, event_type=RealmAuditLog.REALM_PROPERTY_CHANGED, event_time=event_time,
+        acting_user=acting_user, extra_data=ujson.dumps({
+            RealmAuditLog.OLD_VALUE: {'property': 'notifications_stream', 'value': old_value},
+            RealmAuditLog.NEW_VALUE: {'property': 'notifications_stream', 'value': stream_id}
+        }))
+
     event = dict(
         type="realm",
         op="update",
@@ -783,10 +794,19 @@ def do_set_realm_notifications_stream(realm: Realm, stream: Optional[Stream], st
     )
     send_event(realm, event, active_user_ids(realm.id))
 
-def do_set_realm_signup_notifications_stream(realm: Realm, stream: Optional[Stream],
+def do_set_realm_signup_notifications_stream(realm: Realm, stream: Optional[Stream], stream_id: int,
-                                             stream_id: int) -> None:
+                                             acting_user: Optional[UserProfile]=None) -> None:
+    old_value = getattr(realm, 'signup_notifications_stream')
     realm.signup_notifications_stream = stream
     realm.save(update_fields=['signup_notifications_stream'])
+
+    event_time = timezone_now()
+    RealmAuditLog.objects.create(
+        realm=realm, event_type=RealmAuditLog.REALM_PROPERTY_CHANGED, event_time=event_time,
+        acting_user=acting_user, extra_data=ujson.dumps({
+            RealmAuditLog.OLD_VALUE: {'property': 'signup_notifications_stream', 'value': old_value},
+            RealmAuditLog.NEW_VALUE: {'property': 'signup_notifications_stream', 'value': stream_id}
+        }))
     event = dict(
         type="realm",
         op="update",

zerver/tests/test_audit_log.py

@@ -25,6 +25,8 @@ from zerver.lib.actions import (
     do_regenerate_api_key,
     do_set_realm_authentication_methods,
     do_set_realm_message_editing,
+    do_set_realm_notifications_stream,
+    do_set_realm_signup_notifications_stream,
     get_last_message_id,
     get_streams_traffic,
 )
@@ -290,3 +292,37 @@ class TestRealmAuditLog(ZulipTestCase):
 
         self.assertEqual(new_values_seen, new_values_expected)
         self.assertEqual(old_values_seen, old_values_expected)
+
+    def test_set_realm_notifications_stream(self) -> None:
+        now = timezone_now()
+        realm = get_realm('zulip')
+        user = self.example_user('hamlet')
+        old_value = getattr(realm, 'notifications_stream')
+        stream_name = 'test'
+        stream = self.make_stream(stream_name, realm)
+
+        do_set_realm_notifications_stream(realm, stream, stream.id, acting_user=user)
+        self.assertEqual(RealmAuditLog.objects.filter(
+            realm=realm, event_type=RealmAuditLog.REALM_PROPERTY_CHANGED,
+            event_time__gte=now, acting_user=user,
+            extra_data=ujson.dumps({
+                RealmAuditLog.OLD_VALUE: {'property': 'notifications_stream', 'value': old_value},
+                RealmAuditLog.NEW_VALUE: {'property': 'notifications_stream', 'value': stream.id}
+            })).count(), 1)
+
+    def test_set_realm_signup_notifications_stream(self) -> None:
+        now = timezone_now()
+        realm = get_realm('zulip')
+        user = self.example_user('hamlet')
+        old_value = getattr(realm, 'signup_notifications_stream')
+        stream_name = 'test'
+        stream = self.make_stream(stream_name, realm)
+
+        do_set_realm_signup_notifications_stream(realm, stream, stream.id, acting_user=user)
+        self.assertEqual(RealmAuditLog.objects.filter(
+            realm=realm, event_type=RealmAuditLog.REALM_PROPERTY_CHANGED,
+            event_time__gte=now, acting_user=user,
+            extra_data=ujson.dumps({
+                RealmAuditLog.OLD_VALUE: {'property': 'signup_notifications_stream', 'value': old_value},
+                RealmAuditLog.NEW_VALUE: {'property': 'signup_notifications_stream', 'value': stream.id}
+            })).count(), 1)

zerver/views/realm.py

@@ -169,7 +169,8 @@ def update_realm(
                 (new_notifications_stream, recipient, sub) = access_stream_by_id(
                     user_profile, notifications_stream_id)
             do_set_realm_notifications_stream(realm, new_notifications_stream,
-                                              notifications_stream_id)
+                                              notifications_stream_id,
+                                              acting_user=user_profile)
             data['notifications_stream_id'] = notifications_stream_id
 
     if signup_notifications_stream_id is not None:
@@ -180,7 +181,8 @@ def update_realm(
                 (new_signup_notifications_stream, recipient, sub) = access_stream_by_id(
                     user_profile, signup_notifications_stream_id)
             do_set_realm_signup_notifications_stream(realm, new_signup_notifications_stream,
-                                                     signup_notifications_stream_id)
+                                                     signup_notifications_stream_id,
+                                                     acting_user=user_profile)
             data['signup_notifications_stream_id'] = signup_notifications_stream_id
 
     if default_code_block_language is not None: