A JavaScript function that converts a BitTorrent info-hash to a magnet URI with "the best public trackers"

toMagnetURI.js

/**
 * Convert a BitTorrent info-hash to a magnet URI that contains "the best public trackers"
 * @see https://en.wikipedia.org/wiki/Magnet_URI_scheme
 * @see https://github.com/ngosang/trackerslist
 * @example
 * toMagnetURI({hash: '286d2e5b4f8369855328336ac1263ae02a7a60d5', name: 'Ubuntu 18.04 x64'});
 * // returns a magnet link for http://releases.ubuntu.com/18.04/ubuntu-18.04.4-desktop-amd64.iso.torrent
 * 
 * @param {({hash: string, name?: string})} info
 * @returns {string} magnet uri
 */
function toMagnetURI({hash, name = "nameless"}) {
    // @ngosang/trackerslist - Updated 2020-08-03 - trackers_best.txt
    const TRACKERS_LIST =
    `udp://tracker.coppersurfer.tk:6969/announce

    udp://tracker.opentrackr.org:1337/announce

    udp://tracker.openbittorrent.com:80/announce

    udp://tracker.internetwarriors.net:1337/announce

    udp://tracker.leechers-paradise.org:6969/announce

    udp://p4p.arenabg.com:1337/announce

    udp://9.rarbg.to:2710/announce

    udp://9.rarbg.me:2710/announce

    udp://exodus.desync.com:6969/announce

    udp://tracker.cyberia.is:6969/announce

    udp://retracker.lanta-net.ru:2710/announce

    udp://open.stealth.si:80/announce

    udp://tracker3.itzmx.com:6961/announce

    udp://tracker.tiny-vps.com:6969/announce

    http://tracker1.itzmx.com:8080/announce

    udp://tracker.torrent.eu.org:451/announce

    udp://tracker.moeking.me:6969/announce

    udp://ipv4.tracker.harry.lu:80/announce

    udp://bt2.archive.org:6969/announce

    udp://bt1.archive.org:6969/announce
    `;
    
    const trackers = TRACKERS_LIST.trim().split(/\s+/);

    const uri = [
        `magnet:?xt=urn:btih:${hash}`,
        `dn=${encodeURIComponent(name)}`,
        ...trackers.map(tr => `tr=${encodeURIComponent(tr)}`),
    ].join('&');
            
    return uri;
}