如何测试在茉莉花2.5中触发setTimeout的函数？

Question

PlayOscillator(hz: number = 400, durationInSeconds: number = 1){ 
    this._Oscillators[0].frequency.value = hz; 
    this._Oscillators[0].connect(this._MainGainNode); 
    this._activeOscillatorIndex = 0; 

setTimeout(() => { 
    console.info("time out called"); 
    this._Oscillators[this._activeOscillatorIndex].disconnect(this._MainGainNode); 
this._Oscillators[this._activeOscillatorIndex] = undefined; 
}, durationInSeconds * 1000); 
} 

我想测试typeofthis._Oscillators[0]执行setTimeout后，但我无法做到这一点。我已经在这里找到了所有解决方案推荐功能不可用茉莉花2.5

我迄今

 it('Should switch from one oscillator to another',()=>{ 
       let wap = webAudioApiProvider; 
      expect(wap._Oscillators[0]).toBeUndefined(); 
      expect(()=>{wap.PlayOscillator(freq,duration)}).not.toThrow(); 
      expect(wap._Oscillators[0]).toBeUndefined(); 

     }); 

Answer 1

您应该能够使用done参数，因为茉莉花2.0支持：

it('Should switch from one oscillator to another', done => { 
    let wap = webAudioApiProvider; 
    expect(wap._Oscillators[0]).toBeUndefined(); 
    expect(()=>{wap.PlayOscillator(freq,duration)}).not.toThrow(); 

    setTimeout(() => { 
     expect(wap._Oscillators[0]).toBeUndefined(); 
     done(); 
    }, duration * 1000 + 100); // add 100 to ensure this fires after the wap's timeout 
});