添加CombineReducer后无法读取未定义(读取“map”)的属性

我组合了两个reducer函数,一个是返回电影列表,另一个是我正在构建的,用于处理用户将电影添加到“收藏夹列表”的逻辑。

import { combineReducers } from 'redux';
import movieReducer from './movieReducer';
import movieFavReducer from './movieFavReducer';

//combined reducers 
export default combineReducers({ movieReducer, movieFavReducer });

如果我不合并这两个减缩器,只合并movieReducer,我会得到我所有的电影,然而,当我合并这两个减缩器时,我会得到错误消息:

Uncaught TypeError: Cannot read properties of undefined (reading 'map')

以下是相关代码:

import React from 'react';
import { connect } from 'react-redux';
import * as actionCreators from '../actions/movieActions';
import MovieListItem from './MovieListItem';
import MovieFooter from './MovieFooter';

const MovieList = (props)=> {
    const{ movies, favorites } = props
    // const movies = [];

    return (
        <div className="col">
            <table className="table table-striped table-hover">
                <thead>
                <tr>
                    <th>Title</th>
                    <th>Director</th>
                    <th>Genre</th>
                    <th>Metascore</th>
                    <th></th>
                </tr>
                </thead>

                <tbody>
                    {
                        props.movies.map(movie=><MovieListItem key={movie.id} movie={movie}/>)
                    }
                </tbody>
            </table>
            
            <MovieFooter totalMovies={movies.length}/>
        </div>
    );
}

//reaching into state and getting specific properties I want
const mapStateToProps = state => {
    return {
        movies: state.movies,
        favorites: state.movies
    }
}

export default connect(mapStateToProps, actionCreators) (MovieList);

我读过一些解决方案,建议我在映射之前先检查电影中是否包含任何内容,这样就符合了 movies?.map 问题是,这没什么,尽管当我不合并我的减缩器时,电影会被传下来。

请帮我弄清楚