昨天将项目更新到 React v16.0 ，但是 CI 构建出现如下问题：

 Error:
              Enzyme Internal Error: Enzyme expects an adapter to be configured, but found none. To
              configure an adapter, you should call `Enzyme.configure({ adapter: new Adapter() })`
              before using any of Enzyme's top level APIs, where `Adapter` is the adapter
              corresponding to the library currently being tested. For example:
              import Adapter from 'enzyme-adapter-react-15';
              To find out more about this, see http://airbnb.io/enzyme/docs/installation/index.html

查阅文档发现 Enzyme 3.0 Api 发生变化

按照官方的说法，需要在 setup file 中添加如下代码。

// http://airbnb.io/enzyme/docs/installation/react-16.html
// setup file
import { configure } from 'enzyme';
import Adapter from 'enzyme-adapter-react-16';

configure({ adapter: new Adapter() });

那么问题来了，应该添加到什么地方？

尝试添加到每个测试文件前，没有成功
尝试添加到 `karma.conf.js` 的 `files: []` 中，也没有成功。