我正在参加一个测试，其中我应该以这样一种方式编写代码，以便所有单元测试用例都能通过。

案例 1：

  it('should dispatch action when dispatchAction is called', async() => {
    // you need to spy on store's 'dispatch' method
    store = TestBed.get(Store);
    spyOn(store, 'dispatch').and.callThrough();

    // if you call function dispatchAction with 'movies' paramter. expect store to dispatch action='movies'
    component.dispatchAction('movies');
    fixture.detectChanges();

    expect(store.dispatch).toHaveBeenCalledWith('movies');
  });

我的代码：

  dispatchAction($event: string) {
    this.store.dispatch({type: 'movie'});
  }

但是规范失败，抛出了以下错误

Expected spy dispatch to have been called with [ 'movies' ] but actual calls were [ Object({ type: 'movies' }) ].

Reducer，

export function news (state = initialState, action: Action) {
    switch (action.type) {
        case LOAD_SECTION_NEWS: {
            return {
                newsList: mockNewsList,
                filter: action.type
            };
        }
        case FILTER_SUBSECTION: {
            return {
                newsList: mockNewsList,
                filter: action.payload
            };
        }
        default:
            return state;
    }
}

export const getNewsList = (state: any) => {
    return state;
};

export const getFilter = (state: any) => {
    return state;
};

Action

export class NewsActions {
    static LOAD_SECTION_NEWS = '[News] LOAD_SECTION_NEWS';
    static FILTER_SUBSECTION = '[News] FILTER_SUBSECTION';

    LoadSectionNews(list: News[]): Action {
        return {
            type: '',
            payload: ''
        };
    }
    FilterSubsection(subsection: string) {
        return {
            type: '',
            payload: ''
        };
    }
}

我如何修改 Reducer，以便单元测试用例通过。

这个 Ngrx 超出了教学大纲，我不知道。请帮忙。