Question

PS这是我第一次编写测试用例。

环境细节： - Angular 4.4.3

组件

currentToken: string;

constructor(private tokenService: TokenService){}

ngOnInit(): void {
   this.tokenService.getCurrentToken().subscribe((token: string) => {
      this.currentToken = token;
   });
}

TokenService中的

export class TokenService {
   constructor(private router: Router) { }

   getCurrentToken(): Observable<string> {
      const token: string = sessionStorage.getItem("token");
      if (token) {
         return Observable.of(token);
      }else {
         this.router.navigate(['home']);
      }
   }
}

在规格

describe("AccountComponent" , () => {
   let component: AccountComponent;
   let fixture: ComponentFixture<AccountComponent>;

   beforeEach(async(() => {
      TestBed.configureTestingModule({
        imports: [],
        declaration: [ TokenService ]
      }).compileComponents();
   }));

   beforeEach(() => {
     fixture = TestBed.createComponent(AccountComponent);
     component = fixture.createInstance;
     fixture.detectChanges();
     component.ngOnInit();
   });

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

这是一个简单的测试，当我使用angular cli时会出现。你可能已经知道我会收到如下错误。

＆＃34;无法阅读财产＆＃39;订阅＆＃39;未定义＆＃34;

这是我将在所有新组件中编写的常用方法。

TIA

Answer 1

您应该使用FakeService，如下所示

使用返回某些字符串的方法定义假类。
班级
在beforeEach()

在it块中将其修改为toBeDefined()，因为该组件不能真正

describe("AccountComponent" , () => {
   let component: AccountComponent;
   let fixture: ComponentFixture<AccountComponent>;
   let tokenService : TokenService;
   class FakeTokenService {
        getCurrentToken(){
            Observable.of('some string')
        }
   }

   beforeEach(async(() => {
      TestBed.configureTestingModule({
        imports: [],
        declaration: [ ],
        providers: [
            { provide: TokenService, useClass: FakeTokenService }
        ]
      }).compileComponents();
   }));

   beforeEach(() => {
     fixture = TestBed.createComponent(AccountComponent);
     component = fixture.createInstance;
     fixture.detectChanges();
     fixture.debugElement.injector.get(TokenService);
   });

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

ngOnInit上的Mock Observable服务

1 个答案: