#28400: TransactionTestCase will truncate data created from data migration -------------------------------------+------------------------------------- Reporter: Jared | Owner: nobody Mackey | Type: Bug | Status: new Component: Testing | Version: 1.11 framework | Keywords: tests,data- Severity: Normal | migrations Triage Stage: | Has patch: 0 Unreviewed | Needs documentation: 0 | Needs tests: 0 Patch needs improvement: 0 | Easy pickings: 0 UI/UX: 0 | -------------------------------------+------------------------------------- Data migrations that create data in the database do not persist after running tests that inherit from `TransactionTestCase`. The first test that runs on the database works as expected but subsequent tests do not.
Here is an example migration: {{{ def add_group_permissions(apps, schema_editor): for app_config in apps.get_app_configs(): app_config.models_module = True create_permissions(app_config, verbosity=0) app_config.models_module = None Group = apps.get_model('auth', 'Group') Permission = apps.get_model('auth', 'Permission') group, _ = Group.objects.get_or_create(name='demo_group') group.permissions.clear() permission = Permission.objects.get(codename='existing_permission') group.permissions.add(permission) class Migration(migrations.Migration): dependencies = [ ] operations = [ migrations.RunPython(add_group_permissions, reverse_code=migrations.RunPython.noop), migrations.RunPython(lambda apps, schema_editor: ContentType.objects.clear_cache()), # hack to get the ContentType cache to clear ] }}} Here is a test case that will prove that the second test to run will fail with `django.contrib.auth.models.DoesNotExist: Group matching query does not exist.` {{{ class TestGroupsExist(TransactionTestCase): """ One of these tests will fail. Which one depends on which one the test runner runs first. The second one to run will fail. """ def test_group_exists_1(self): self.assertIsNotNone(Group.objects.get_by_natural_key('demo_group')) def test_group_exists_2(self): self.assertIsNotNone(Group.objects.get_by_natural_key('demo_group')) }}} The following log is found after the first test is ran. `TRUNCATE ... "auth_group_permissions", "auth_group", ...;; args=None` A possible solution to this is to re-run data only migrations after truncating the tables. -- Ticket URL: <https://code.djangoproject.com/ticket/28400> Django <https://code.djangoproject.com/> The Web framework for perfectionists with deadlines. -- You received this message because you are subscribed to the Google Groups "Django updates" group. To unsubscribe from this group and stop receiving emails from it, send an email to django-updates+unsubscr...@googlegroups.com. To post to this group, send email to django-updates@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/django-updates/053.92f4e7c8eed10f4567ec60879867af1d%40djangoproject.com. For more options, visit https://groups.google.com/d/optout.