fix bug in the "you're going oncall" push notification copy (#1922)

# What this PR does

## Which issue(s) this PR fixes

User reported receiving a push notification that they were going oncall
~12mins before the shift started but the notification copy instead
showed this:

![Screenshot_20230511-105817](https://github.com/grafana/oncall/assets/9406895/a9851c5f-97e1-4e2d-9f3a-fd3a3272ad08)

## Checklist

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

CHANGELOG.md

@@ -5,6 +5,12 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## Unreleased
+
+### Fixed
+
+- Fix bug in the "You're Going Oncall" push notification copy by @joeyorlando ([#1922](https://github.com/grafana/oncall/pull/1922))
+
 ## v1.2.21 (2023-05-09)
 
 ### Added

engine/apps/mobile_app/tasks.py

@@ -314,6 +314,9 @@ def should_we_send_going_oncall_push_notification(
     Currently we will send notifications for the following scenarios:
     - schedule is starting in user's "configured notification timing preference" +/- a 4 minute buffer
     - schedule is starting within the next fifteen minutes
+
+    Returns `None` if conditions are not met for the user to receive a push notification. Otherwise returns
+    an `int` which represents the # of seconds until the oncall shift starts.
     """
     NOTIFICATION_TIMING_BUFFER = 7 * 60  # 7 minutes in seconds
     FIFTEEN_MINUTES_IN_SECONDS = 15 * 60
@@ -417,13 +420,13 @@ def conditionally_send_going_oncall_push_notifications_for_schedule(schedule_pk)
 
             cache_key = _generate_going_oncall_push_notification_cache_key(user_pk, schedule_event)
             already_sent_this_push_notification = cache_key in relevant_notifications_already_sent
+            seconds_until_going_oncall = should_we_send_going_oncall_push_notification(
+                now, mobile_app_user_settings, schedule_event
+            )
 
-            if (
-                should_we_send_going_oncall_push_notification(now, mobile_app_user_settings, schedule_event)
-                and not already_sent_this_push_notification
-            ):
+            if seconds_until_going_oncall is not None and not already_sent_this_push_notification:
                 message = _get_youre_going_oncall_fcm_message(
-                    user, schedule, device_to_notify, mobile_app_user_settings.going_oncall_notification_timing
+                    user, schedule, device_to_notify, seconds_until_going_oncall
                 )
                 _send_push_notification(device_to_notify, message)
                 cache.set(cache_key, True, PUSH_NOTIFICATION_TRACKING_CACHE_KEY_TTL)

engine/apps/mobile_app/tests/test_your_going_oncall_notification.py

@@ -217,8 +217,9 @@ def test_conditionally_send_going_oncall_push_notifications_for_schedule(
         ),
     ]
 
+    seconds_until_shift_starts = 58989
     mock_get_youre_going_oncall_fcm_message.return_value = mock_fcm_message
-    mock_should_we_send_going_oncall_push_notification.return_value = True
+    mock_should_we_send_going_oncall_push_notification.return_value = seconds_until_shift_starts
     mock_oncall_schedule_final_events.return_value = final_events
 
     schedule = make_schedule(organization, schedule_class=OnCallScheduleWeb)
@@ -236,7 +237,7 @@ def test_conditionally_send_going_oncall_push_notifications_for_schedule(
 
     tasks.conditionally_send_going_oncall_push_notifications_for_schedule(schedule.pk)
 
-    mock_get_youre_going_oncall_fcm_message.assert_called_once_with(user, schedule, device, ONCALL_TIMING_PREFERENCE)
+    mock_get_youre_going_oncall_fcm_message.assert_called_once_with(user, schedule, device, seconds_until_shift_starts)
     mock_send_push_notification.assert_called_once_with(device, mock_fcm_message)
     assert cache.get(cache_key) is True