angular - 我如何为公共静态方法编写 jasmine-karma 测试用例？

我正在为一个方法具有公共静态特性的服务编写 jasmine-karma 测试用例。然而，我无法在 spec.ts 文件中访问它们或为它们编写测试用例。有人能告诉我该怎么做吗？

这是我在 app.service.ts 中的方法

public static getModifiedDate(dateVal: any): string {
    if ('' === dateVal) {
      return null;
    }
    const year = dateVal.substring(
      dateVal.lastIndexOf('/') + 1,
      dateVal.length
    );
    const month = dateVal.substring(0, dateVal.indexOf('/'));
    const date = dateVal.substring(
      dateVal.indexOf('/') + 1,
      dateVal.lastIndexOf('/')
    );
    return year + '-' + month + '-' + date;
  }

在 spec.ts 文件中，我无法为这个函数编写测试用例，正如我尝试的那样，

describe('AppService', () => {
  let service: AppService;
  beforeEach(async(() => {
    TestBed.configureTestingModule({
      imports: [HttpClientTestingModule],
      providers: [RestClientService, AppService]
    });
    service = TestBed.get(AppService);
  }));

  it('getModifieddate should return date in the expected format', () => {
    const date = service.getModifiedDate('04/20/2017');
    expect(date).toEqual('2017-04-20');
  }); 
});

显示错误，因为 getModifiedDate 是一个公共静态方法。解决这个问题的正确方法是什么？

答案＃1

您应该以静态方式调用静态方法：AppService.getModifiedDate。测试可以简化如下：

describe('AppService', () => {
  it('getModifieddate should return date in the expected format', () => {
    const date = AppService.getModifiedDate('04/20/2017');
    expect(date).toEqual('2017-04-20');
  }); 
});

答案＃2

有几件事你可以尝试，下面是这些：

• it('getModifieddate should return date in the expected format', () => {
      const date = (service as any).getModifiedDate('04/20/2017');
      expect(date).toEqual('2017-04-20');
    });
  

• it('getModifieddate should return date in the expected format', () => {
      spyOn(service as any, 'getModifiedDate').and.callFake(() => {return '2017-04-20'; });
      const date = (service as any).getModifiedDate('04/20/2017');
      expect(date).toEqual('2017-04-20');
    });
  

• it('getModifieddate should return date in the expected format', () => {
      const date = AppService.getModifiedDate('04/20/2017');
      expect(date).toEqual('2017-04-20');
    });
  

希望这能帮到你。如果你有任何疑问，请告诉我。