def test_form_valid_without_object(self, super_mock):
"""
Test :py:meth:`.ModelFormMixin.form_valid` without ``self.object`` set.
"""
super_class = Mock()
super_class.form_valid.return_value = 'form-valid'
super_mock.return_value = super_class
form = Mock()
model_obj = Mock()
mixin = ModelFormMixin()
mixin.object = None
mixin.document_class = Mock(return_value=model_obj)
self.assertEqual('form-valid', mixin.form_valid(form))
form.populate_obj.assert_called_once_with(model_obj)
mixin.object.save.assert_called_once_with()
super_mock.assert_called_once_with(ModelFormMixin, mixin)
super_class.form_valid.assert_called_once_with(form)
