m3u downloader and id3tag fixer

m3u.js

const m3u = require('m3ujs');
const {promisify} = require('util');
const sanitize = require("sanitize-filename");
const fetch = require('node-fetch');
const ID3Writer = require('browser-id3-writer');
const fs = require('fs');
const path = require("path");
const readFileAsync = promisify(fs.readFile);
const writeFileAsync = promisify(fs.writeFile);
const jsmediatags = require("jsmediatags");

var content = fs.readFileSync('./playlist.m3u').toString();
var parsed = m3u.parse(content);
var tracks = parsed.tracks;

function wait(ms) {return new Promise(function(resolve) {setTimeout(function () {resolve();}, ms)})}

function tagReadAsync(from) {
    return new Promise((resolve, reject) => {
        new jsmediatags.Reader(from)
            .setTagsToRead(['artist', 'title'])
            .read({
                onSuccess(meta) {
                    resolve({
                        artist: meta.tags.title,
                        title: meta.tags.artist
                    })
                },
                onError(error) {
                    resolve({

                    });
                    console.log(error.info);
                }
            })
    });
}

async function saveTrack(track) {
    var name = sanitize(track.title);
    var artist = name.split('-')[0].trim();
    var title = name.split('-')[1].trim();
    var url = track.file;
    var savePath = path.resolve(__dirname, 'music', name + '.mp3');
    const res = await fetch(url);
    const fileStream = fs.createWriteStream(savePath);
    await new Promise((resolve, reject) => {
        res.body.pipe(fileStream);
        res.body.on('error', (err) => { reject(err);});
        fileStream.on('finish', () => {
            resolve();
        });
    });

    console.log(`Finished downloading: ${name}`);
    return {
        savePath, artist, title
    };
}

async function fixTags(data) {
    let { savePath, artist, title } = data;
    let originalTags = await tagReadAsync(savePath);
    if (originalTags.artist && originalTags.title) {
        return;
    } else {
        artist = originalTags.artist || artist;
        title = originalTags.title || title;
    }

    const songBuffer = await readFileAsync(savePath);
    const writer = new ID3Writer(songBuffer);
    writer.setFrame('TIT2', title).setFrame('TPE1', [artist]);
    writer.addTag();
    const taggedSongBuffer = Buffer.from(writer.arrayBuffer);
    await writeFileAsync(savePath, taggedSongBuffer);
}

(async function() {
    for(let track in tracks) {
        let a = await saveTrack(tracks[track]);
        let b = fixTags(a);
        await wait(25);
    }
})();