"Jasmine Angular Mock"组件属性 [英] Jasmine Angular Mock component attribute

问题描述

运行命令:

ng test --codeCoverage = true --progress = false --watch = false

ng test --codeCoverage=true --progress=false --watch=false

错误消息:

TypeError:无法读取未定义的属性"substring"

TypeError: Cannot read property 'substring' of undefined

组件的NgOnInit

NgOnInit of the component

private serv: ExtratosMensaisService,
ngOnInit(): void {
  const serventia: Serventia = this.serv.getServentiaSelecionada();
  const competencia: Competencia = this.serv.getCompetenciaSelecionada();
  const titularidade = serventia.titularidade.substring(0, 1).toUpperCase();
}

服务文件方法:

getServentiaSelecionada(): Serventia {
   return JSON.parse(sessionStorage.getItem('serventia'));
}

我知道该属性是未定义的，但是我无法使其变为已定义". 我已经尝试过使用jasmine.createSpyObj()中的第三个数组来监视属性，但错误仍然存​​在. 并尝试在mockExtratosMensaisService returnValue(of({object}))上传递JSON对象，并尝试执行以下操作:

I understand that the attribute is undefined, but I can't make it 'defined'. I already tried to use the third array from the jasmine.createSpyObj() to spy on properties but the error continues. And tried to pass an JSON object on the mockExtratosMensaisService returnValue(of({ object })), and tried this:

 mockExtratosMensaisService.getServentiaSelecionada.and.returnValue(of({ titularidade: 123 }));

我使用了错误的方法吗?我需要此测试通过.

Am I using the wrong approach? I need this test to pass.

spec.component文件:

spec.component file:

describe('PrestacaoContasTitularComponent', () => {
let component: PrestacaoContasTitularComponent;
let fixture: ComponentFixture<PrestacaoContasTitularComponent>;
const mockExtratosMensaisService = jasmine.createSpyObj('Obj',
['getServentiaSelecionada', 'getCompetenciaSelecionada'],
['titularidade']);

beforeEach(async(() => {
TestBed.configureTestingModule({
  imports: [ RouterTestingModule, HttpClientTestingModule ],
  declarations: [ PrestacaoContasTitularComponent ],
  providers: [ MatDialog, Overlay, MatSnackBar,
    { provide: ActivatedRoute, useValue: {} },
    { provide: InjectionToken, useValue: {} },
    { provide: MAT_DIALOG_SCROLL_STRATEGY, useValue: {} },
    { provide: ExtratosMensaisService, useValue: mockExtratosMensaisService }
  ]
})
.compileComponents();
}));

beforeEach(() => {
  fixture = TestBed.createComponent(PrestacaoContasTitularComponent);
  component = fixture.componentInstance;
  mockExtratosMensaisService.getServentiaSelecionada.and.returnValue(of({ titularidade: 123 }));
  mockExtratosMensaisService.getCompetenciaSelecionada.and.returnValue(of({ data: 'competencia'        }));
  fixture.detectChanges();
});

it('should create', () => {
  expect(component).toBeTruthy();
});

});

推荐答案

尝试将模拟更改为:

const mockExtratosMensaisService = jasmine.createSpyObj('Obj', ['getServentiaSelecionada', 'getCompetenciaSelecionada']);

然后做

mockExtratosMensaisService.getServentiaSelecionada.and.returnValue({ titularidade: 'abc' });. 

我将123更改为"abc"，因为我不确定子字符串是否适用于数字.以前，您仍在返回，这是不正确的，因为它不是可观察的，它是常规的JavaScript对象.

I changed 123 to 'abc' because I am not sure if substring would work on a number. Before, you were still returning of and this is not correct because it is not an observable, it is a regular JavaScript object.

这篇关于"Jasmine Angular Mock"组件属性的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！