Angular 如何为公共静态方法编写jasmine karma测试用例？

我正在为一个方法本质上是公共静态的服务编写jasmine karma测试用例。无论怎样，我都无法访问它们或在spec.ts文件中为它们编写测试用例。有人能告诉我怎么做吗

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，我无法在尝试时编写此函数的测试用例

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');
  }); 
});

它显示错误，因为getModifiedDate是一个公共静态方法。

---

解决此问题的正确方法是什么？

您应该以静态方式调用静态方法：

AppService.getModifiedDate

。试验可简化如下：

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

---

您可以尝试以下几种方法：

---

希望这有帮助。如果您有任何疑问，请告诉我。

它确实有效！！非常感谢您的帮助：）

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');
  });