异步自定义茉莉花匹配器-“预期未定义”错误

Question

我创建了一个自定义茉莉花匹配器：

export class OwnMatchers implements jasmine.CustomMatcherFactories {
  [index: string]: any;  
  public toCheck(util: jasmine.MatchersUtil, customEqualityTesters: Array<jasmine.CustomEqualityTester>) {

    return {
      compare: async function (actual:any, expected: any) {
        if (expected === undefined) {
          expected = '';
        }

        const result = <jasmine.CustomMatcherResult>{};
        let resultTest = await SreenShotTest.Check(expected.Data);          

        result.pass = util.equals(resultTest, true, customEqualityTesters);

        if (result.pass)
          {result.message = "Success" + ' ' + expected.Data;}
        else
          {result.message = "Not Success" + ' ' + expected.Data;}

        return result;
      }
    }

  }
}

我用那个

const customOwnMatchers = new OwnMatchers();

describe('App', () => {
  let page: AppPage;

  beforeEach(() => {
    page = new AppPage();
    jasmine.addMatchers(customOwnMatchers);
  });

   it('Test 1', async() => {            
      ...
      ...
      await (<any>expect()).toCheck({Data: '1'});
    });
}); 

运行测试（ng e2e）后，我收到此错误消息：

预期为undefined以检查Object（{Data：'1'}）。

谢谢您的回答