Angular 8 Jasmine与HTTP请求不匹配

我有一个Angular服务发出一些HTTP请求，我想测试它是否以正确的方式发出请求

在其依赖项中，它还有一个

EnvironmentService

，它根据环境返回正确的API端点，我用Jasmine模仿了它

我的测试如下所示：

describe('ShipmentsService', () => {

    let httpTestingController: HttpTestingController;
    let service: ShipmentsService;
    const envSpy = jasmine.createSpyObj('EnvironmentService', ['getRestEndpoint', 'dev']);

    beforeEach(() => {
        TestBed.configureTestingModule({
            providers: [
                ShipmentsService,
                {provide: EnvironmentService, useValue: envSpy}
            ],
            imports: [HttpClientTestingModule]
        });

        httpTestingController = TestBed.get(HttpTestingController);
        service = TestBed.get(ShipmentsService);
    });

    it('does the right HTTP request', () => {
        envSpy.getRestEndpoint.and.returnValue('foo');
        service.doStuff(123);
        expect(envSpy.getRestEndpoint)
            .toHaveBeenCalledWith('changePackingProperties');

        const request = httpTestingController.expectOne('foo');
        request.flush({shipmentId: 123});
        httpTestingController.verify();    
    });
});

这是我的

ShipmentsService

方法：

doStuff(shipmentId: number) {
    let path = this.environmentService.getRestEndpoint('changePackingProperties');
    return this.http.post(path, body, {headers}).pipe(map(
      (response) => response
    ));
}

---

我遗漏了什么？

遗漏的是，我的服务方法确实返回了一个可观察的

，
，因此要完成测试，需要
订阅它

因此，为了使测试能够工作，实际的服务调用需要

service.doStuff(123).subscribe(() => {});