Cache upgrade_deadline on CourseEnrollment objects

common/djangoapps/student/models.py

@@ -1696,7 +1696,7 @@ class CourseEnrollment(models.Model):
     def verified_mode(self):
         return CourseMode.verified_mode_for_course(self.course_id)
 
-    @property
+    @cached_property
     def upgrade_deadline(self):
         """
         Returns the upgrade deadline for this enrollment, if it is upgradeable.

common/djangoapps/student/tests/test_models.py

@@ -132,6 +132,21 @@ class CourseEnrollmentTests(SharedModuleStoreTestCase):
         self.assertEqual(Schedule.objects.all().count(), 0)
         self.assertEqual(enrollment.upgrade_deadline, course_mode.expiration_datetime)
 
+
+    @skip_unless_lms
+    # NOTE: We mute the post_save signal to prevent Schedules from being created for new enrollments
+    @factory.django.mute_signals(signals.post_save)
+    def test_upgrade_deadline_with_schedule(self):
+        """ The property should use either the CourseMode or related Schedule to determine the deadline. """
+        course = CourseFactory(self_paced=True)
+        CourseModeFactory(
+            course_id=course.id,
+            mode_slug=CourseMode.VERIFIED,
+            # This must be in the future to ensure it is returned by downstream code.
+            expiration_datetime=datetime.datetime.now(pytz.UTC) + datetime.timedelta(days=1),
+        )
+        enrollment = CourseEnrollmentFactory(course_id=course.id, mode=CourseMode.AUDIT)
+
         # The schedule's upgrade deadline should be used if a schedule exists
         DynamicUpgradeDeadlineConfiguration.objects.create(enabled=True)
         schedule = ScheduleFactory(enrollment=enrollment)