在更改检测之前调用创建的间谍

Question

我想在触发更改检测之前调用创建的间谍方法。这是我的嘲笑 class.

const stubStudentService: Pick<StudentsCrudService, keyof StudentsCrudService> =
  {
    getAllStudents: jasmine
      .createSpy('getAllStudents')
      .and.returnValue(of(studentPayload)),
     ...other methods
  };

如何在 fixture.detectChanges()

之前调用 getAllStudents

 beforeEach(() => {
    fixture = TestBed.createComponent(StudentsListComponent);
    component = fixture.componentInstance;
    <-- want to call that spy here --->
    fixture.detectChanges();
  });

因为这个问题，我想这样做。但不知道如何根据我的模拟服务更改解决方案

Answer 1

你需要在这里使用TestBed.inject：

beforeEach(() => {
  TestBed.configureTestingModule({
    // ...
    providers: [
      {
        provide: StudentsCrudService,
        useValue: stubStudentService,
      },
    ],
  });
});

beforeEach(() => {
  fixture = TestBed.createComponent(StudentsListComponent);
  component = fixture.componentInstance;

  const studentsCrudService = TestBed.inject(StudentsCrudService);
  // spyOn(studentsCrudService, 'getAllStudents')...;

  fixture.detectChanges();
});