wcs: test num queries on page display (#40675)

tests/test_wcs.py

@@ -16,8 +16,10 @@ from django.apps import apps
 from django.conf import settings
 from django.core.cache import cache
 from django.core.urlresolvers import reverse
+from django.db import connection
 from django.test import override_settings
 from django.test.client import RequestFactory
+from django.test.utils import CaptureQueriesContext
 from django.utils.six.moves.urllib import parse as urlparse
 
 import mock
@@ -1209,6 +1211,26 @@ def test_import_export_pages_with_links():
     assert new_item.cached_json == item.cached_json
 
 
+@wcs_present
+def test_view_page_with_wcs_cells_num_queries(app, admin_user):
+    page = Page.objects.create(title=u'bar', slug='index', order=1)
+    for i in range(0, 15):
+        WcsCurrentDraftsCell.objects.create(
+            page=page,
+            placeholder='content',
+            order=i)
+    for i in range(15, 50):
+        WcsCurrentFormsCell.objects.create(
+            page=page,
+            placeholder='content',
+            order=i)
+    app = login(app)
+    app.get('/')  # load once to populate caches
+    with CaptureQueriesContext(connection) as ctx:
+        app.get('/')
+        assert len(ctx.captured_queries) == 160
+
+
 @wcs_present
 def test_hourly():
     appconfig = apps.get_app_config('wcs')