AA-158: Fix date ordering for multiple events on the same date

This change will prefer putting assignments before other course
events (such as end date or verification deadline date) in the
case where they share the same date.

lms/djangoapps/courseware/courses.py

@@ -461,7 +461,17 @@ def get_course_date_blocks(course, user, request=None, include_access=False,
     Return the list of blocks to display on the course info page,
     sorted by date.
     """
-    block_classes = [
+    blocks = []
+    if RELATIVE_DATES_FLAG.is_enabled(course.id):
+        blocks.append(CourseExpiredDate(course, user))
+        blocks.extend(get_course_assignment_date_blocks(
+            course, user, request, num_return=num_assignments,
+            include_access=include_access, include_past_dates=include_past_dates,
+        ))
+
+    # Adding these in after the assignment blocks so in the case multiple blocks have the same date,
+    # these blocks will be sorted to come after the assignments. See https://openedx.atlassian.net/browse/AA-158
+    default_block_classes = [
         CourseEndDate,
         CourseStartDate,
         TodaysDate,
@@ -469,15 +479,9 @@ def get_course_date_blocks(course, user, request=None, include_access=False,
         VerifiedUpgradeDeadlineDate,
     ]
     if not course.self_paced and certs_api.get_active_web_certificate(course):
-        block_classes.insert(0, CertificateAvailableDate)
+        default_block_classes.insert(0, CertificateAvailableDate)
 
-    blocks = [cls(course, user) for cls in block_classes]
-    if RELATIVE_DATES_FLAG.is_enabled(course.id):
-        blocks.append(CourseExpiredDate(course, user))
-        blocks.extend(get_course_assignment_date_blocks(
-            course, user, request, num_return=num_assignments,
-            include_access=include_access, include_past_dates=include_past_dates,
-        ))
+    blocks.extend([cls(course, user) for cls in default_block_classes])
 
     return sorted((b for b in blocks if b.date and (b.is_enabled or include_past_dates)), key=date_block_key_fn)
 

lms/djangoapps/courseware/tests/test_date_summary.py

@@ -551,7 +551,10 @@ class CourseDateSummaryTest(SharedModuleStoreTestCase):
         CourseEnrollmentFactory(course_id=course.id, user=verified_user, mode=CourseMode.VERIFIED)
         course.certificate_available_date = datetime.now(utc) + timedelta(days=7)
         enable_course_certificates(course)
-        CertificateAvailableDate(course, audit_user)
+        expected_blocks = [
+            CourseEndDate, CourseStartDate, TodaysDate, VerificationDeadlineDate, CertificateAvailableDate
+        ]
+        self.assert_block_types(course, verified_user, expected_blocks)
         for block in (CertificateAvailableDate(course, audit_user), CertificateAvailableDate(course, verified_user)):
             self.assertIsNotNone(course.certificate_available_date)
             self.assertEqual(block.date, course.certificate_available_date)