Question

我在Angular 6中拥有此类服务：

   export class AppService {

     setValues(): Observable<any> {

       const vm: any = this;
       return new Observable(observer => {
       vm.currentValues().subscribe(data => {
           // continue modifying data and reset it

        });
     });
   }

   public currentValues(): Observable<any> {


   return new Observable(observer => {
     observer.next('data goes here')

    });

  } 
 }

currentValues（）是相当随机的，因此无法对其进行中继。如何在我的unittest文件中模拟它并在测试setValues（）方法时使用它？

我尝试了以下方法，但看不到如何使用？

export function mockCurrentValues () : Observable<any> {

    return of(
      'data'
    )
  }

Answer 1

假设AppService是@Injectable()，并且您正在为提供程序编写单元测试。您可以使用spys提供的Jasmine Framework

https://jasmine.github.io/2.0/introduction.html#section-Spies

import { getTestBed, TestBed } from '@angular/core/testing';
import { AppService } from 'path/to/app/service';
import { of } from 'rxjs';

describe( 'App Service', function() {
    let appService : AppService;

    beforeEach( function() {
        TestBed.configureTestingModule( {
            providers: [ AppService ],
        } );
        const injector = getTestBed();
        appService = injector.get( AppService );

        spyOn( appService, 'currentValues' ).and.callFake( () => {
            return of( 'data' );
        } );
    } );

    describe( 'setValues', function() {

        it( 'should set correct values', function() {
            appService.setValues().subscribe();
            // setValues will receive 'data' from the spy we just created while calling currentValues() method
            // write your unit tests here
        } );

    } );
} );

Answer 2

您可以发布完整的代码吗？无论如何，我认为您应该这样尝试returnValue：

    const injector = getTestBed();
    appService = injector.get( AppService );

    // spy the internal method setValues() calls now and return observable

    spyOn( appService, 'currentValues' ).and.returnValue(of(data));

    appService.setValues().subscribe(data=>{
        // do your test here
        done()
    }

    )

在同一服务中模拟功能以进行单元测试

2 个答案: