REST: Fix bug 335 tests

One extra query is necessary for patch/cover endpoints to fetch labels
information.

Author: fstachura

patchwork/api/cover.py

@@ -114,7 +114,10 @@ class CoverList(ListAPIView):
     def get_queryset(self):
         return (
             Cover.objects.all()
-            .prefetch_related('series__project')
+            .prefetch_related(
+                'series__project',
+                'labels',
+            )
             .select_related('project', 'submitter', 'series')
             .defer('content', 'headers')
         )

patchwork/tests/unit/api/test_cover.py

@@ -153,7 +153,7 @@ def test_list_bug_335(self):
         series = create_series()
         create_covers(5, series=series)
 
-        with self.assertNumQueries(3):
+        with self.assertNumQueries(4):
             self.client.get(self.api_url())
 
     @utils.store_samples('cover-detail')

patchwork/tests/unit/api/test_patch.py

@@ -254,7 +254,7 @@ def test_list_bug_335(self):
         series = create_series()
         create_patches(5, series=series)
 
-        with self.assertNumQueries(5):
+        with self.assertNumQueries(6):
             self.client.get(self.api_url())
 
     @utils.store_samples('patch-detail')