Handle Unauthorized exception on posting alert group to telegram (#3540)

## Which issue(s) this PR fixes
https://github.com/grafana/oncall-private/issues/2377

## Checklist

- [x] Unit, integration, and e2e (if applicable) tests updated
- [x] Documentation added (or `pr:no public docs` PR label added if not
required)
- [x] `CHANGELOG.md` updated (or `pr:no changelog` PR label added if not
required)

engine/apps/telegram/models/connectors/personal.py

@@ -167,6 +167,13 @@ class TelegramToUserConnector(models.Model):
                     notification_policy,
                     UserNotificationPolicyLogRecord.ERROR_NOTIFICATION_TELEGRAM_TOKEN_ERROR,
                 )
+            elif e.message == "Forbidden: user is deactivated":
+                TelegramToUserConnector.create_telegram_notification_error(
+                    alert_group,
+                    self.user,
+                    notification_policy,
+                    UserNotificationPolicyLogRecord.ERROR_NOTIFICATION_TELEGRAM_USER_IS_DEACTIVATED,
+                )
             else:
                 raise e
 

engine/apps/telegram/tests/test_personal_connector.py

@@ -3,7 +3,7 @@ from unittest.mock import patch
 import pytest
 from telegram import error
 
-from apps.base.models import UserNotificationPolicy
+from apps.base.models import UserNotificationPolicy, UserNotificationPolicyLogRecord
 from apps.telegram.client import TelegramClient
 from apps.telegram.models import TelegramMessage
 
@@ -47,3 +47,52 @@ def test_personal_connector_replied_message_not_found(
         text="One more notification about this 👆",
         reply_to_message_id=telegram_message.message_id,
     )
+
+
+@pytest.mark.parametrize(
+    "side_effect,notification_error_code",
+    [
+        (
+            error.Unauthorized("Forbidden: bot was blocked by the user"),
+            UserNotificationPolicyLogRecord.ERROR_NOTIFICATION_TELEGRAM_BOT_IS_DELETED,
+        ),
+        (error.Unauthorized("Invalid token"), UserNotificationPolicyLogRecord.ERROR_NOTIFICATION_TELEGRAM_TOKEN_ERROR),
+        (
+            error.Unauthorized("Forbidden: user is deactivated"),
+            UserNotificationPolicyLogRecord.ERROR_NOTIFICATION_TELEGRAM_USER_IS_DEACTIVATED,
+        ),
+    ],
+)
+@pytest.mark.django_db
+def test_personal_connector_send_link_to_channel_message_handle_exceptions(
+    side_effect,
+    notification_error_code,
+    make_organization_and_user,
+    make_telegram_user_connector,
+    make_user_notification_policy,
+    make_alert_receive_channel,
+    make_alert_group,
+):
+    # set up a user with Telegram account connected
+    organization, user = make_organization_and_user()
+    user_connector = make_telegram_user_connector(user)
+    notification_policy = make_user_notification_policy(
+        user,
+        UserNotificationPolicy.Step.NOTIFY,
+        notify_by=UserNotificationPolicy.NotificationChannel.TELEGRAM,
+        important=False,
+    )
+
+    # create an alert group with an existing Telegram message in user's DM
+    alert_receive_channel = make_alert_receive_channel(organization)
+    alert_group = make_alert_group(alert_receive_channel)
+
+    assert not user.personal_log_records.exists()
+
+    with patch.object(TelegramClient, "send_message", side_effect=side_effect) as mock_send_message:
+        user_connector.send_link_to_channel_message(alert_group, notification_policy)
+
+    mock_send_message.assert_called_once()
+    log_records = user.personal_log_records.filter(alert_group=alert_group)
+    assert log_records.count() == 1
+    assert log_records.first().notification_error_code == notification_error_code