Merge pull request #18436 from edx/noraiz/EDUCATOR-2773

add delay in score recalculation on enrollment update

common/djangoapps/student/models.py

@@ -103,6 +103,7 @@ UNENROLLED_TO_ENROLLED = 'from unenrolled to enrolled'
 ALLOWEDTOENROLL_TO_UNENROLLED = 'from allowed to enroll to enrolled'
 UNENROLLED_TO_UNENROLLED = 'from unenrolled to unenrolled'
 DEFAULT_TRANSITION_STATE = 'N/A'
+SCORE_RECALCULATION_DELAY_ON_ENROLLMENT_UPDATE = 30
 
 TRANSITION_STATES = (
     (UNENROLLED_TO_ALLOWEDTOENROLL, UNENROLLED_TO_ALLOWEDTOENROLL),
@@ -1342,7 +1343,15 @@ class CourseEnrollment(models.Model):
             # Only emit mode change events when the user's enrollment
             # mode has changed from its previous setting
             self.emit_event(EVENT_NAME_ENROLLMENT_MODE_CHANGED)
-            ENROLLMENT_TRACK_UPDATED.send(sender=None, user=self.user, course_key=self.course_id)
+            # this signal is meant to trigger a score recalculation celery task,
+            # `countdown` is added to celery task as delay so that cohort is duly updated
+            # before starting score recalculation
+            ENROLLMENT_TRACK_UPDATED.send(
+                sender=None,
+                user=self.user,
+                course_key=self.course_id,
+                countdown=SCORE_RECALCULATION_DELAY_ON_ENROLLMENT_UPDATE
+            )
 
     def send_signal(self, event, cost=None, currency=None):
         """

common/djangoapps/student/tests/test_enrollment.py

@@ -12,7 +12,13 @@ from nose.plugins.attrib import attr
 from course_modes.models import CourseMode
 from course_modes.tests.factories import CourseModeFactory
 from openedx.core.djangoapps.embargo.test_utils import restrict_course
-from student.models import CourseEnrollment, CourseEnrollmentAllowed, CourseFullError, EnrollmentClosedError
+from student.models import (
+    CourseEnrollment,
+    CourseEnrollmentAllowed,
+    CourseFullError,
+    EnrollmentClosedError,
+    SCORE_RECALCULATION_DELAY_ON_ENROLLMENT_UPDATE,
+)
 from student.roles import CourseInstructorRole, CourseStaffRole
 from student.tests.factories import CourseEnrollmentAllowedFactory, UserFactory
 from util.testing import UrlResetMixin
@@ -340,3 +346,34 @@ class EnrollmentTest(UrlResetMixin, SharedModuleStoreTestCase):
         # Still same
         cea.refresh_from_db()
         self.assertEqual(cea.user, user1)
+
+    def test_score_recalculation_on_enrollment_update(self):
+        """
+        Test that an update in enrollment cause score recalculation.
+        Note:
+        Score recalculation task must be called with a delay of SCORE_RECALCULATION_DELAY_ON_ENROLLMENT_UPDATE
+        """
+        course_modes = ['verified', 'audit']
+
+        for mode_slug in course_modes:
+            CourseModeFactory.create(
+                course_id=self.course.id,
+                mode_slug=mode_slug,
+                mode_display_name=mode_slug,
+            )
+        CourseEnrollment.enroll(self.user, self.course.id, mode="audit")
+
+        local_task_args = dict(
+            user_id=self.user.id,
+            course_key=str(self.course.id)
+        )
+
+        with patch(
+            'lms.djangoapps.grades.tasks.recalculate_course_and_subsection_grades_for_user.apply_async',
+            return_value=None
+        ) as mock_task_apply:
+            CourseEnrollment.enroll(self.user, self.course.id, mode="verified")
+            mock_task_apply.assert_called_once_with(
+                countdown=SCORE_RECALCULATION_DELAY_ON_ENROLLMENT_UPDATE,
+                kwargs=local_task_args
+            )

lms/djangoapps/grades/signals/handlers.py

@@ -241,12 +241,13 @@ def recalculate_course_grade_only(sender, course, course_structure, user, **kwar
 
 @receiver(ENROLLMENT_TRACK_UPDATED)
 @receiver(COHORT_MEMBERSHIP_UPDATED)
-def recalculate_course_and_subsection_grades(sender, user, course_key, **kwargs):
+def recalculate_course_and_subsection_grades(sender, user, course_key, countdown=None, **kwargs):  # pylint: disable=unused-argument
     """
     Updates a saved course grade, forcing the subsection grades
     from which it is calculated to update along the way.
     """
     recalculate_course_and_subsection_grades_for_user.apply_async(
+        countdown=countdown,
         kwargs=dict(
             user_id=user.id,
             course_key=six.text_type(course_key)