如何在角度单元测试中模拟函数实例值？

Question

我具有以下功能

  renderMap(data: any): void {
    const map = this;
    this.chartOptions = {
    chart: {
      events: {
       load(): void {
         map.cardObject = this.userOptions.series[0].data[0].dataObj;
        }
       }
     } 
   }
  }

我想从规范中模拟this.userOptions，

 it('should load highchart map on load', async () => {
   const { instance, fixture, find } = await shallow.render();
   instance.renderMap(data);
   instance.userOptions ={series: [{data: [{dataObj: "test"}]}]};
   fixture.detectChanges();

 });

但是这里的“ instance.userOptions”不是组件实例变量，而是函数实例。如何模拟呢？