perf: add CompressedCacheResponseMixin to CourseRecommendationsViewSet (

#4489)

course_discovery/apps/api/cache.py

@@ -154,14 +154,14 @@ class CompressedCacheResponseMixin():
     list_cache_timeout = settings.REST_FRAMEWORK_EXTENSIONS['DEFAULT_CACHE_RESPONSE_TIMEOUT']
 
     @conditional_decorator(
-        settings.USE_API_CACHING,
+        lambda: settings.USE_API_CACHING,
         compressed_cache_response(key_func=list_cache_key_func, timeout=list_cache_timeout),
     )
     def list(self, request, *args, **kwargs):
         return super().list(request, *args, **kwargs)
 
     @conditional_decorator(
-        settings.USE_API_CACHING,
+        lambda: settings.USE_API_CACHING,
         compressed_cache_response(key_func=object_cache_key_func, timeout=object_cache_timeout),
     )
     def retrieve(self, request, *args, **kwargs):

course_discovery/apps/api/utils.py

@@ -129,11 +129,19 @@ def reviewable_data_has_changed(obj, new_key_vals, exempt_fields=None):
     return changed_fields
 
 
-def conditional_decorator(condition, decorator):
+def conditional_decorator(condition_getter, decorator):
     """
-    Util decorator that allows for only using the given decorator arg if the condition passes
+    Util decorator that applies the given decorator only if the condition passes.
+    The condition is evaluated at runtime via the `condition_getter` callable, allowing dynamic condition checking.
+    If callable evaluates to `True`, the provided decorator is applied, otherwise, the function remains unmodified.
     """
-    return decorator if condition else lambda x: x
+    def wrapper(func):
+        def wrapped(*args, **kwargs):
+            if condition_getter():
+                return decorator(func)(*args, **kwargs)
+            return func(*args, **kwargs)
+        return wrapped
+    return wrapper
 
 
 def decode_image_data(image_data):

course_discovery/apps/api/v1/tests/test_views/test_courses.py

@@ -12,6 +12,7 @@
 from django.db.models.functions import Lower
 from django.db.models.query import Prefetch
 from django.db.models.signals import m2m_changed, pre_save
+from django.test import override_settings
 from edx_toggles.toggles.testutils import override_waffle_switch
 from rest_framework.reverse import reverse
 from testfixtures import LogCapture
@@ -2666,6 +2667,7 @@ def test_html_restricted(self):
         self.assertContains(response, 'Invalid HTML received: h1 tag is not allowed', status_code=400)
 
     @responses.activate
+    @override_settings(USE_API_CACHING=True)
     def test_recommendations(self):
         courses_sharing_program = CourseFactory.create_batch(2)
         ProgramFactory(courses=[self.course, *courses_sharing_program])
@@ -2684,4 +2686,9 @@ def test_recommendations(self):
         with self.assertNumQueries(19, threshold=3):
             url = reverse('api:v1:course_recommendations-detail', kwargs={'key': self.course.key})
             response = self.client.get(url)
-        assert response.status_code == 200
+            assert response.status_code == 200
+
+        with self.assertNumQueries(0, threshold=3):
+            url = reverse('api:v1:course_recommendations-detail', kwargs={'key': self.course.key})
+            response = self.client.get(url)
+            assert response.status_code == 200

course_discovery/apps/api/v1/views/courses.py

@@ -530,7 +530,7 @@ def retrieve(self, request, *args, **kwargs):
         return Response(serializer.data)
 
 
-class CourseRecommendationViewSet(RetrieveModelMixin, viewsets.GenericViewSet):
+class CourseRecommendationViewSet(CompressedCacheResponseMixin, RetrieveModelMixin, viewsets.GenericViewSet):
     filter_backends = (DjangoFilterBackend, )
     lookup_field = 'key'
     lookup_value_regex = COURSE_ID_REGEX