问题的解决方法是在测试组件的之前手动创建mock store。在创建mock store之前，将使用的spies和mock selectors设置为初始值。然后创建一个mock store实例来传递到测试组件中。

下面是一个示例代码：

import { provideMockStore } from '@ngrx/store/testing';

describe('Component', () => {
  let store: MockStore;

  beforeEach(() => {
    TestBed.configureTestingModule({
      imports: [ ... ],
      providers: [
        provideMockStore({ initialState }),
        // other providers
      ]
    });

    store = TestBed.inject(MockStore);
    
    // set up the spies and selectors here with initial values
  });

  it('should display the correct value from the store', () => {
    const expectedValue = 'foo';

    // update the mock store with the expected value
    store.setState({ value: expectedValue });

    // create the component to test here
    const fixture = TestBed.createComponent(Component);
    const component = fixture.componentInstance;

    fixture.detectChanges();

    // assert that the component displays the expected value
    expect(component.value).toBe(expectedValue);
  });
});