fix: Environments metadata n+1 for project admin (#3101)

api/permissions/permission_service.py

@@ -124,7 +124,10 @@ def get_permitted_environments_for_user(
     """
 
     if is_user_project_admin(user, project):
-        return project.environments.all()
+        queryset = project.environments.all()
+        if prefetch_metadata:
+            return queryset.prefetch_related("metadata")
+        return queryset
 
     base_filter = get_base_permission_filter(
         user, Environment, permission_key, tag_ids=tag_ids

api/tests/unit/environments/test_unit_environments_views.py

@@ -639,7 +639,8 @@ def test_view_environment_with_staff__query_count_is_expected(
 
     with_environment_permissions([VIEW_ENVIRONMENT], environment_id=environment_2.id)
 
-    # One additional query for an unrelated, unfixable N+1 issue.
+    # One additional query for an unrelated, unfixable N+1 issue that deals with
+    # the defer logic around filtered environments.
     expected_query_count += 1
 
     # Then
@@ -649,6 +650,45 @@ def test_view_environment_with_staff__query_count_is_expected(
     assert response.status_code == status.HTTP_200_OK
 
 
+def test_view_environment_with_admin__query_count_is_expected(
+    admin_client: APIClient,
+    environment: Environment,
+    project: Project,
+    django_assert_num_queries: Callable[[int], None],
+    environment_metadata_a: Metadata,
+    environment_metadata_b: Metadata,
+    required_a_environment_metadata_field: MetadataModelField,
+    environment_content_type: ContentType,
+) -> None:
+    # Given
+    url = reverse("api-v1:environments:environment-list")
+    data = {"project": project.id}
+
+    expected_query_count = 5
+    # When
+    with django_assert_num_queries(expected_query_count):
+        response = admin_client.get(url, data=data, content_type="application/json")
+
+    assert response.status_code == status.HTTP_200_OK
+
+    # Add an environment to make sure the query count is the same.
+    environment_2 = Environment.objects.create(
+        name="Second Environment", project=project
+    )
+    Metadata.objects.create(
+        object_id=environment_2.id,
+        content_type=environment_content_type,
+        model_field=required_a_environment_metadata_field,
+        field_value="10",
+    )
+
+    # Then
+    with django_assert_num_queries(expected_query_count):
+        response = admin_client.get(url, data=data, content_type="application/json")
+
+    assert response.status_code == status.HTTP_200_OK
+
+
 @pytest.mark.parametrize(
     "client",
     [lazy_fixture("admin_master_api_key_client"), lazy_fixture("admin_client")],