有没有办法监视Promise构造器？

Question

我有这个功能

public pick(config?: FilePickerConfig): Promise<FilePickerResult> {
    return new Promise<FilePickerResult>(resolve => {
      this.pickWithCallbacks(resolve, resolve, config);
    });
  }

我想测试对this.pickWithCallbacks的调用是否将函数的resolve参数作为第一个和第二个参数。

有没有办法用jest或jasmine来做到这一点呢？我曾试图监视window, 'Promise'，但没有起作用。

编辑:这不是Spying on a constructor using Jasmine的解体，因为这是我尝试过的，但没有起作用。

我已经尝试过了：

      const dummyResolve = () => { };
      const promiseSpy = spyOn(window, 'Promise').and.callFake((dummyResolve)=>{});
      const pickWithCallbacksSpy = spyOn(sut, 'pickWithCallbacks');
      sut.pick();

      expect(pickWithCallbacksSpy).toHaveBeenCalledWith(dummyResolve, dummyResolve, undefined);

Answer 1

所以最后我只留下了Promise，做他的事情，我捕获了resolve回调

    test('on success should call pickWithCallbacks with the resolve function of a promise', (done) => {
      const cordovaExecSpy = spyOn(sut, 'pickWithCallbacks');
      const dummyReturn = {};
      sut.pick().then(obtained => {
        expect(obtained).toBe(dummyReturn);
        done();
      });

      const capturedOnSucess = cordovaExecSpy.calls.mostRecent().args[0];
      capturedOnSucess(dummyReturn);
    });

    test('on Error should call pickWithCallbacks with the resolve function of a promise', (done) => {
      const cordovaExecSpy = spyOn(sut, 'pickWithCallbacks');
      const dummyReturn = {};
      sut.pick().then(obtained => {
        expect(obtained).toBe(dummyReturn);
        done();
      });

      const capturedOnError = cordovaExecSpy.calls.mostRecent().args[1];
      capturedOnError(dummyReturn);
    });