組件中的watch如下:player(isPlay) {  if (isPlay) {    this.playState = 'play'  } else {    this.playState = 'pause'  }}測(cè)試文件Home.spec.js中的相關(guān)用例如下it('播放狀態(tài)切換', () => {  const Constructor = Vue.extend(Home)  const vm = new Constructor().$mount()  vm.playerShow = true  Vue.nextTick( () => {    expect(vm.playState).to.equal("play")  })  vm.playerShow = false  Vue.nextTick( () => {    expect(vm.playState).to.equal("pause")    done()  })})這樣寫了之后查看覆蓋率報(bào)告,發(fā)現(xiàn)組件中watch部分代碼沒(méi)有被覆蓋(都是紅的)請(qǐng)教下如何寫用例才能夠把watch的代碼覆蓋到