fix: ensure navigation sidebar serves fresh data after course publish

lms/djangoapps/course_home_api/outline/tests/test_view.py

@@ -907,3 +907,37 @@ def test_vertical_icon_determined_by_icon_class(self):
         response = self.client.get(reverse('course-home:course-navigation', args=[self.course.id]))
         vertical_data = response.data['blocks'][str(self.vertical.location)]
         assert vertical_data['icon'] == 'video'
+
+    def test_navigation_serves_fresh_data_after_publish(self):
+        """
+        Regression test: the navigation sidebar should serve fresh data when
+        the modulestore has changed but the block structure cache is stale.
+
+        This simulates a production scenario where:
+        1. A unit is deleted and the course is auto-published
+        2. The block structure rebuild Celery task is queued with a 30s delay
+        3. A learner hits the navigation endpoint during that 30s window
+
+        Without the fix, stale block structure data gets cached for 1 hour.
+        """
+        self.add_blocks_to_course()
+        CourseEnrollment.enroll(self.user, self.course.id, CourseMode.VERIFIED)
+
+        # First request — populates both block structure and navigation caches
+        response = self.client.get(self.url)
+        assert response.status_code == 200
+        sequential_data = response.data['blocks'][str(self.sequential.location)]
+        assert str(self.vertical.location) in sequential_data['children']
+
+        # Delete the vertical directly in the modulestore. Signals are disabled
+        # in ModuleStoreTestCase, so the block structure cache is now stale —
+        # mirroring the 30s window in production before the rebuild task runs.
+        self.store.delete_item(self.vertical.location, self.user.id)
+        update_outline_from_modulestore(self.course.id)
+
+        # Without the fix, this returns stale data with the deleted vertical.
+        # With the fix, update_collected_if_needed() detects staleness and rebuilds.
+        response = self.client.get(self.url)
+        assert response.status_code == 200
+        sequential_data = response.data['blocks'][str(self.sequential.location)]
+        assert str(self.vertical.location) not in sequential_data['children']

lms/djangoapps/course_home_api/outline/views.py

@@ -51,6 +51,7 @@
 from lms.djangoapps.courseware.views.views import get_cert_data
 from lms.djangoapps.grades.course_grade_factory import CourseGradeFactory
 from lms.djangoapps.utils import OptimizelyClient
+from openedx.core.djangoapps.content.block_structure.api import get_block_structure_manager
 from openedx.core.djangoapps.content.course_overviews.api import get_course_overview_or_404
 from openedx.core.djangoapps.content.learning_sequences.api import get_user_course_outline
 from openedx.core.djangoapps.course_groups.cohorts import get_cohort
@@ -483,6 +484,9 @@ def get(self, request, *args, **kwargs):
             course_blocks = cache.get(cache_key)
 
         if not course_blocks:
+            # Ensure the block structure cache is up-to-date before reading.
+            get_block_structure_manager(course_key).update_collected_if_needed()
+
             if getattr(enrollment, 'is_active', False) or bool(staff_access):
                 course_blocks = get_course_outline_block_tree(request, course_key_string, request.user)
             elif allow_public_outline or allow_public or user_is_masquerading: