feat: prefetch image related fields in event API

events/api.py

@@ -2408,6 +2408,16 @@ def _optimize_include(includes, queryset):
                 "keywords__data_source",
                 "keywords__publisher",
             )
+
+        if "images" in includes:
+            queryset = queryset.prefetch_related(
+                "images__created_by",
+                "images__data_source",
+                "images__last_modified_by",
+                "images__license",
+                "images__publisher",
+            )
+
         return queryset
 
     def get_queryset(self):

events/tests/test_event_get.py

@@ -12,12 +12,13 @@
 from django.utils import timezone
 from django.utils.timezone import localtime
 from freezegun import freeze_time
+from pytest_django.asserts import assertNumQueries
 from resilient_logger.models import ResilientLogEntry
 from rest_framework import status
 
 from events.models import Event, Language, License, PublicationStatus
 from events.tests.conftest import APIClient
-from events.tests.factories import EventFactory, OfferFactory
+from events.tests.factories import EventFactory, ImageFactory, OfferFactory
 from events.tests.utils import (
     assert_fields_exist,
     create_super_event,
@@ -1892,41 +1893,99 @@ def test_sub_events_increase_query_count_sanely(
     discover sub-sub events. Sub-sub events should also require 8 queries.
     """
 
-    def get_num_queries():
-        with CaptureQueriesContext(connections[DEFAULT_DB_ALIAS]) as queries:
-            response = get_list(api_client, query_string=qs)
-            assert response.status_code == status.HTTP_200_OK
-
-        return len(queries)
+    def get_and_check_response():
+        response = get_list(api_client, query_string=qs)
+        assert response.status_code == status.HTTP_200_OK
+        return response
 
     event_1 = EventFactory()
     event_2 = EventFactory()
 
+    def count_queries():
+        with CaptureQueriesContext(connections[DEFAULT_DB_ALIAS]) as queries:
+            get_and_check_response()
+        return len(queries)
+
     # Do one warmup list, there's some savepoint/insert happening
     # on first call related to test setup that would give higher
     # than expected number of queries.
-    get_num_queries()
+    count_queries()
 
-    base_count = get_num_queries()
+    base_count = count_queries()
 
     sub_event_1 = EventFactory(super_event=event_1)
-    one_sub_event_count = get_num_queries()
-
-    assert one_sub_event_count == base_count + sub_event_query_count
+    with assertNumQueries(base_count + sub_event_query_count):
+        get_and_check_response()
 
     # More than one sub event should NOT increase number of queries
     sub_event_2 = EventFactory(super_event=event_2)
-    assert get_num_queries() == one_sub_event_count
+    one_sub_event_count = base_count + sub_event_query_count
+    with assertNumQueries(one_sub_event_count):
+        get_and_check_response()
 
     EventFactory(super_event=sub_event_1)
-    one_sub_sub_event_count = get_num_queries()
-    assert one_sub_sub_event_count == one_sub_event_count + sub_sub_event_query_count
+    one_sub_sub_event_count = one_sub_event_count + sub_sub_event_query_count
+    with assertNumQueries(one_sub_sub_event_count):
+        get_and_check_response()
 
     # More than one sub-sub event should NOT increase number of queries
     EventFactory(super_event=sub_event_2)
     EventFactory(super_event=sub_event_2)
 
-    assert get_num_queries() == one_sub_sub_event_count
+    with assertNumQueries(one_sub_sub_event_count):
+        get_and_check_response()
+
+
+@pytest.mark.django_db
+def test_images_with_include_uses_prefetch_optimization(
+    api_client, data_source, organization, user
+):
+    """
+    Test that include=images uses prefetch_related optimization for image
+    related fields (created_by, data_source, last_modified_by, license, publisher).
+
+    The prefetch_related optimization in the EventViewSet._optimize_include method
+    should efficiently fetch all related fields for images, preventing N+1 query
+    problems when multiple events with images are listed.
+    """
+
+    def count_queries(query_string=""):
+        with CaptureQueriesContext(connections[DEFAULT_DB_ALIAS]) as queries:
+            response = get_list(api_client, query_string=query_string)
+            assert response.status_code == status.HTTP_200_OK
+        return len(queries)
+
+    _license = License.objects.create(name="Test License", url="http://test.license")
+
+    for i in range(3):
+        event = EventFactory(data_source=data_source, publisher=organization)
+        image = ImageFactory(
+            data_source=data_source,
+            publisher=organization,
+            created_by=user,
+            last_modified_by=user,
+            license=_license,
+            url=f"http://test.image/{i}.jpg",
+        )
+        event.images.add(image)
+
+    baseline_queries = count_queries(query_string="include=images")
+
+    for i in range(3, 6):
+        event = EventFactory(data_source=data_source, publisher=organization)
+        image = ImageFactory(
+            data_source=data_source,
+            publisher=organization,
+            created_by=user,
+            last_modified_by=user,
+            license=_license,
+            url=f"http://test.image/{i}.jpg",
+        )
+        event.images.add(image)
+
+    with assertNumQueries(baseline_queries):
+        response = get_list(api_client, query_string="include=images")
+        assert response.status_code == status.HTTP_200_OK
 
 
 @pytest.mark.django_db