push_notifications: Use SentPushNotificationResult dataclass.

Refactoring, no functional change.

This commit refactors `send_e2ee_push_notification_apple`
and `send_e2ee_push_notification_android` to return a
`SentPushNotificationResult` dataclass.

It's a cleaner protocol than passing a mutable data structure
`delete_device_ids` as argument and updating it within
functions.

Fixes part of #35368.

zerver/tests/test_e2ee_push_notifications.py

@@ -28,6 +28,7 @@ from zerver.lib.timestamp import datetime_to_timestamp
 from zerver.models import PushDevice, UserMessage
 from zerver.models.realms import get_realm
 from zerver.models.scheduled_jobs import NotificationTriggers
+from zilencer.lib.push_notifications import SentPushNotificationResult
 from zilencer.models import RemoteRealm, RemoteRealmCount
 
 
@@ -260,7 +261,11 @@ class SendPushNotificationTest(E2EEPushNotificationTestCase):
         with (
             self.mock_fcm() as mock_fcm_messaging,
             mock.patch(
-                "zilencer.lib.push_notifications.send_e2ee_push_notification_apple", return_value=1
+                "zilencer.lib.push_notifications.send_e2ee_push_notification_apple",
+                return_value=SentPushNotificationResult(
+                    successfully_sent_count=1,
+                    delete_device_ids=[],
+                ),
             ),
             self.assertLogs("zerver.lib.push_notifications", level="INFO") as zerver_logger,
             self.assertLogs("zilencer.lib.push_notifications", level="WARNING") as zilencer_logger,

zilencer/lib/push_notifications.py

@@ -1,7 +1,7 @@
 import asyncio
 import logging
 from collections.abc import Iterable
-from dataclasses import asdict
+from dataclasses import asdict, dataclass
 
 from aioapns import NotificationRequest
 from django.utils.timezone import now as timezone_now
@@ -23,14 +23,20 @@ from zilencer.models import RemotePushDevice, RemoteRealm
 logger = logging.getLogger(__name__)
 
 
+@dataclass
+class SentPushNotificationResult:
+    successfully_sent_count: int
+    delete_device_ids: list[int]
+
+
 def send_e2ee_push_notification_apple(
     apns_requests: list[NotificationRequest],
     apns_remote_push_devices: list[RemotePushDevice],
-    delete_device_ids: list[int],
+) -> SentPushNotificationResult:
-) -> int:
     import aioapns
 
     successfully_sent_count = 0
+    delete_device_ids: list[int] = []
     apns_context = get_apns_context()
 
     if apns_context is None:
@@ -38,7 +44,10 @@ def send_e2ee_push_notification_apple(
             "APNs: Dropping a notification because nothing configured. "
             "Set ZULIP_SERVICES_URL (or APNS_CERT_FILE)."
         )
-        return successfully_sent_count
+        return SentPushNotificationResult(
+            successfully_sent_count=successfully_sent_count,
+            delete_device_ids=delete_device_ids,
+        )
 
     async def send_all_notifications() -> Iterable[
         tuple[RemotePushDevice, aioapns.common.NotificationResult | BaseException]
@@ -66,21 +75,28 @@ def send_e2ee_push_notification_apple(
             remote_push_device.save(update_fields=["expired_time"])
             delete_device_ids.append(result_info.delete_device_id)
 
-    return successfully_sent_count
+    return SentPushNotificationResult(
+        successfully_sent_count=successfully_sent_count,
+        delete_device_ids=delete_device_ids,
+    )
 
 
 def send_e2ee_push_notification_android(
     fcm_requests: list[firebase_messaging.Message],
     fcm_remote_push_devices: list[RemotePushDevice],
-    delete_device_ids: list[int],
+) -> SentPushNotificationResult:
-) -> int:
+    successfully_sent_count = 0
+    delete_device_ids: list[int] = []
+
     try:
         batch_response = firebase_messaging.send_each(fcm_requests, app=fcm_app)
     except firebase_exceptions.FirebaseError:
         logger.warning("Error while pushing to FCM", exc_info=True)
-        return 0
+        return SentPushNotificationResult(
+            successfully_sent_count=successfully_sent_count,
+            delete_device_ids=delete_device_ids,
+        )
 
-    successfully_sent_count = 0
     for idx, response in enumerate(batch_response.responses):
         # We enumerate to have idx to track which token the response
         # corresponds to. send_each() preserves the order of the messages,
@@ -114,7 +130,10 @@ def send_e2ee_push_notification_android(
                     error,
                 )
 
-    return successfully_sent_count
+    return SentPushNotificationResult(
+        successfully_sent_count=successfully_sent_count,
+        delete_device_ids=delete_device_ids,
+    )
 
 
 def send_e2ee_push_notifications(
@@ -181,15 +200,21 @@ def send_e2ee_push_notifications(
 
     apple_successfully_sent_count = 0
     if len(apns_requests) > 0:
-        apple_successfully_sent_count = send_e2ee_push_notification_apple(
+        sent_push_notification_result = send_e2ee_push_notification_apple(
-            apns_requests, apns_remote_push_devices, delete_device_ids
+            apns_requests,
+            apns_remote_push_devices,
         )
+        apple_successfully_sent_count = sent_push_notification_result.successfully_sent_count
+        delete_device_ids.extend(sent_push_notification_result.delete_device_ids)
 
     android_successfully_sent_count = 0
     if len(fcm_requests) > 0:
-        android_successfully_sent_count = send_e2ee_push_notification_android(
+        sent_push_notification_result = send_e2ee_push_notification_android(
-            fcm_requests, fcm_remote_push_devices, delete_device_ids
+            fcm_requests,
+            fcm_remote_push_devices,
         )
+        android_successfully_sent_count = sent_push_notification_result.successfully_sent_count
+        delete_device_ids.extend(sent_push_notification_result.delete_device_ids)
 
     return {
         "apple_successfully_sent_count": apple_successfully_sent_count,