异步有时返回未定义

调用以下方法时：

getLyrics: async function(song) {
    const body = await this.getSongBody(song);
    const lyrics = await cheerio.text(body('.lyrics'));
    return lyrics;
} 

因此：

genius.getLyrics('What a wonderful')
    .then((res) => console.log(res))
    .catch((err) => console.log(err.message));

一切正常，控制台中弹出Louise Armstrong的“多么美好的世界”的歌词。

但是，当我运行相同的代码但在“ cheerio.text ...”前面没有“ await”时，有时会产生歌词，而有时会在控制台中显示“ undefined”。现在让我抓狂了一段时间的是，“ cheerio.text ...”没有返回承诺（尽管“ getSongBody”可以实现），所以据我所知，不需要“等待”它完成。

我显然缺少有关异步/等待的东西，但不知道是什么。任何帮助将不胜感激！

谢谢

编辑：添加了可重复的示例，如下所示：

const fetch = require('node-fetch');
const cheerio = require('cheerio');


// API
function geniusApi(token) {
    this._token = token;
    this._auth = {'Authorization': 'Bearer ' + this._token};
};

geniusApi.prototype = {  
    getSongURL : async function(search_keyword){
        const res = await fetch('https://api.genius.com/search?q=' + 
                                 search_keyword,{headers: this._auth});
        const body = await res.text();
        const body_parsed = JSON.parse(body);

        if (body_parsed.response.hits.length == 0){
            console.log('No such song found');
            throw Error('No such song found');
        } 

        const url = body_parsed.response.hits[0].result.url;
        return url;
    },

    getSongBody: async function (song){
        const url = await this.getSongURL(song);
        const response = await fetch(url);
        const body = await response.text();
        const body_parsed = cheerio.load(body);
        return body_parsed;
    },

    getLyrics: async function(song) {
        const body = await this.getSongBody(song);
        const lyrics = cheerio.text(body('.lyrics'));
        return lyrics;
    }
}

// TEST EXAMPLE
const token = 
'OTh1EYlsNdO1kELVwcevqLPtsgq3FrxfShIXg_w0EaEd8CHZrJWbWvN8Be773Cyr';
const genius = new geniusApi(token);

genius.getLyrics('What a wonderful')
    .then((res) => console.log(res))
    .catch((err) => console.log(err.message));