• react:16.3.0-alpha.1
• jest: “22.3.0”
• enzyme: 3.3.0
• typescript: 2.7.1

码：

class Foo extends React.PureComponent<undefined,undefined>{
   bar:number;
   async componentDidMount() {
     this.bar = 0;
     let echarts = await import('echarts'); // async import
     this.bar = 100;
   }
}

测试：

describe('...', () => {
  test('...', async () => {
    const wrapper = shallow(<Foo/>);
    const instance = await wrapper.instance();
    expect(instance.bar).toBe(100);
  });
});

错误：

Expected value to be:
  100
Received:
  0