角茉莉花测试无法通过ngOninit测试

Question

我为我的角度应用程序编写了一个茉莉花测试。但是我在ngOninit（）上遇到了错误

TypeError: Cannot read property 'cStations' of undefined 

我的代码如下：-

public ngOnInit(): void {
    if (this.sResult.cStations) {
      this.cStations = this.sResult.cStations;
    } else if (this.sResult.rs) {
      this.cStations = this.sResult.rs.length > 0 ? this.sResult.rs[0].cStations : undefined;
    }
  }

我的单元测试如下：-

describe('BarChartHorizontalComponent', () => {
  let component: BarChartHorizontalComponent;
  let fixture: ComponentFixture<BarChartHorizontalComponent>;
  let cStations: CStation;
  beforeEach(async(() => {
    TestBed.configureTestingModule({
      declarations: [ BarChartHorizontalComponent ]
    })
    .compileComponents();
  }));

  beforeEach(() => {
    fixture = TestBed.createComponent(BarChartHorizontalComponent);
    component = fixture.componentInstance;
    component.cStations = [];
    fixture.detectChanges();
  });
  afterEach(() => {
    fixture.destroy();
  });

  it('should have input value', () => {
    expect(component.cStations).toBeTruthy();
  });
});

问题是如何在测试中定义或初始化ngOninit函数的属性

任何解决方案？

Answer 1

替换

 component.cStations = [];

使用

 component.sResult = {cStations: []};