Jest 测试 window.scroll 监听器

问：

我有一个通过addEventListener附加的窗口滚动事件侦听器。它只是在我到达页面底部时向页面添加额外的电影。 我正在尝试使用笑话来测试它。但是我想不出正确的方法。要么我得到一个测试通过，但处理滚动的函数行没有代码覆盖率。 这是我在 react 中的组件（我删除了经过测试的多余部分）：

import React, { useState, useCallback, useEffect } from 'react';
import { useSelector, useDispatch, shallowEqual } from 'react-redux';

import { apiPathUpdated, selectQuery } from '../../modules/query/index';
import {
  selectMovies, loadMovies, addMovies, addCurrentMovieTrailerKey,
} from '../../modules/movies/index';
import { loadGenres, selectGenres } from '../../modules/genres/index';
import { updateStatus, selectStatus } from '../../modules/status/index';
import { genreFilterUpdated, selectGenreId } from '../../modules/filters/index';

import SearchResultsPage from './SearchResultsPage';

const SearchResultsPageContainer = () => {

  useEffect(() => {
    const handleScroll = () => {
      if (window.innerHeight + window.pageYOffset === document.body.clientHeight) {
        page += 1; //this line stays uncovered
        fetchUrl = getFetchUrl(searchQuery, page); //this line stays uncovered
        dispatch(addMovies(fetchUrl)); //this line stays uncovered
      }
    };
    window.addEventListener('scroll', handleScroll);

    if (page * pageSize >= movies.length && movies.length !== 0) {
      window.removeEventListener('scroll', handleScroll);
      dispatch(updateStatus('loaded'));
    }

    return () => window.removeEventListener('scroll', handleScroll);
  }, [apiPath, searchQuery, genreId]);

  return (
    <SearchResultsPage {...bunch of props}/>
  );
};

export default SearchResultsPageContainer;

这是我对组件的开玩笑测试（我还删除了额外的测试用例，所以摆脱了一些混乱）：

import React from 'react';
import ShallowRenderer from 'react-test-renderer/shallow';
import SearchResultsPageContainer from '../index';

let mockQuerySlice;
let mockGenres;
let mockMovie;
let mockMovies;
let mockMoviesSlice;
let mockFiltersSlice;
let mockStatusSlice;
let mockUseSelector;
let triggerMockUseSelector;
let renderer;
let result;

const map = {};
window.addEventListener = jest.fn((event, cb) => {
  map[event] = cb;
});
const spy = jest.spyOn(window, 'addEventListener');

beforeEach(() => {
  renderer = new ShallowRenderer();
  renderer.render(<SearchResultsPageContainer />);
  result = renderer.getRenderOutput();
});

afterEach(() => {
  renderer = null;
  result = null;
});

describe('render SearchResultsPage component', () => {
  it('handles window.scroll event correctly', () => {
    map.scroll();
    expect(spy).toHaveBeenCalled();
  });
});

我尝试使用这个解决方案，但它没有涵盖必要的代码行。（我觉得我错过了什么，但我不知道是什么）