Schedule fetching rosters for sections

After a sucesful course roster fetch, if the course has sections, we will
schedule a task to fetch the rosters for that course's sections.

lms/tasks/roster.py

@@ -237,6 +237,15 @@ def fetch_course_roster(*, lms_course_id) -> None:
             lms_course = request.db.get(LMSCourse, lms_course_id)
             roster_service.fetch_course_roster(lms_course)
 
+            # Check the if course has any sections, if it does, schedule fetching its rosters
+            if request.db.scalars(
+                select(LMSSegment.id).where(
+                    LMSSegment.lms_course_id == lms_course_id,
+                    LMSSegment.type == "canvas_section",
+                )
+            ).first():
+                fetch_canvas_sections_roster.delay(lms_course_id=lms_course_id)
+
 
 @app.task(
     acks_late=True,
@@ -268,3 +277,19 @@ def fetch_segment_roster(*, lms_segment_id) -> None:
         with request.tm:
             assignment = request.db.get(LMSSegment, lms_segment_id)
             roster_service.fetch_canvas_group_roster(assignment)
+
+
+@app.task(
+    acks_late=True,
+    autoretry_for=(Exception,),
+    max_retries=2,
+    retry_backoff=3600,
+    retry_backoff_max=7200,
+)
+def fetch_canvas_sections_roster(*, lms_course_id) -> None:
+    """Fetch the roster for all sections of a given course."""
+    with app.request_context() as request:
+        roster_service: RosterService = request.find_service(RosterService)
+        with request.tm:
+            lms_course = request.db.get(LMSCourse, lms_course_id)
+            roster_service.fetch_canvas_sections_roster(lms_course)

tests/unit/lms/tasks/roster_test.py

@@ -8,6 +8,7 @@
     fetch_assignment_roster,
     fetch_course_roster,
     fetch_segment_roster,
+    fetch_canvas_sections_roster,
     schedule_fetching_assignment_rosters,
     schedule_fetching_course_rosters,
     schedule_fetching_rosters,
@@ -25,6 +26,20 @@ def test_fetch_course_roster(self, roster_service, db_session):
 
         roster_service.fetch_course_roster.assert_called_once_with(lms_course)
 
+    def test_fetch_course_roster_with_sections(
+        self, roster_service, db_session, fetch_canvas_sections_roster
+    ):
+        lms_course = factories.LMSCourse()
+        factories.LMSSegment(lms_course=lms_course, type="canvas_section")
+        db_session.flush()
+
+        fetch_course_roster(lms_course_id=lms_course.id)
+
+        roster_service.fetch_course_roster.assert_called_once_with(lms_course)
+        fetch_canvas_sections_roster.delay.assert_called_once_with(
+            lms_course_id=lms_course.id
+        )
+
     def test_fetch_assignment_roster(self, roster_service, db_session):
         assignment = factories.Assignment()
         db_session.flush()
@@ -41,6 +56,14 @@ def test_fetch_segment_roster(self, roster_service, db_session):
 
         roster_service.fetch_canvas_group_roster.assert_called_once_with(lms_segment)
 
+    def test_fetch_canvas_sections_roster(self, roster_service, db_session):
+        lms_course = factories.LMSCourse()
+        db_session.flush()
+
+        fetch_canvas_sections_roster(lms_course_id=lms_course.id)
+
+        roster_service.fetch_canvas_sections_roster.assert_called_once_with(lms_course)
+
     def test_schedule_fetching_rosters(
         self,
         schedule_fetching_assignment_rosters,
@@ -302,6 +325,10 @@ def fetch_assignment_roster(self, patch):
     def fetch_segment_roster(self, patch):
         return patch("lms.tasks.roster.fetch_segment_roster")
 
+    @pytest.fixture
+    def fetch_canvas_sections_roster(self, patch):
+        return patch("lms.tasks.roster.fetch_canvas_sections_roster")
+
     @pytest.fixture
     def schedule_fetching_segment_rosters(self, patch):
         return patch("lms.tasks.roster.schedule_fetching_segment_rosters")