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Diffstat (limited to 'tests/model_forms')
| -rw-r--r-- | tests/model_forms/tests.py | 35 |
1 files changed, 35 insertions, 0 deletions
diff --git a/tests/model_forms/tests.py b/tests/model_forms/tests.py index 5e443011c2..2af5b5a07d 100644 --- a/tests/model_forms/tests.py +++ b/tests/model_forms/tests.py @@ -828,6 +828,41 @@ class ModelToDictTests(TestCase): # Ensure many-to-many relation appears as a list self.assertIsInstance(d['categories'], list) + def test_reuse_prefetched(self): + # model_to_dict should not hit the database if it can reuse + # the data populated by prefetch_related. + categories = [ + Category(name='TestName1', slug='TestName1', url='url1'), + Category(name='TestName2', slug='TestName2', url='url2'), + Category(name='TestName3', slug='TestName3', url='url3') + ] + for c in categories: + c.save() + writer = Writer(name='Test writer') + writer.save() + + art = Article( + headline='Test article', + slug='test-article', + pub_date=datetime.date(1988, 1, 4), + writer=writer, + article='Hello.' + ) + art.save() + for c in categories: + art.categories.add(c) + + art = Article.objects.prefetch_related('categories').get(pk=art.pk) + + with self.assertNumQueries(0): + d = model_to_dict(art) + + #Ensure all many-to-many categories appear in model_to_dict + for c in categories: + self.assertIn(c.pk, d['categories']) + #Ensure many-to-many relation appears as a list + self.assertIsInstance(d['categories'], list) + class OldFormForXTests(TestCase): def test_base_form(self): |