test_migrations.py 文件源码

def test_custom_migration_operation(self):
        project_state = self.set_up_test_model()
        operation = AddField(
            app_label='tests',
            model_name='pony',
            name='yellow',
            field=models.BooleanField(default=True)
        )
        new_state = project_state.clone()
        operation.state_forwards('tests', new_state)

        self.assertColumnNotExists('tests_pony', 'yellow')
        with connection.schema_editor() as editor:
            operation.database_forwards('tests', editor, project_state, new_state)

        self.assertColumnExists('tests_pony', 'yellow')
        with connection.schema_editor() as editor:
            operation.database_backwards('tests', editor, new_state, project_state)

        self.assertColumnNotExists('tests_pony', 'yellow')