def test_form_invalid(self): """ Test :py:meth:`.FormMixin.form_invalid`. """ mixin = FormMixin() mixin.get_context_data = Mock(return_value={'foo': 'bar'}) mixin.render_to_response = Mock(return_value='response') form_mock = Mock() self.assertEqual('response', mixin.form_invalid(form=form_mock)) mixin.get_context_data.assert_called_once_with(form=form_mock) mixin.render_to_response.assert_called_once_with({'foo': 'bar'})