snippet for TMI.js to log subscriber and/or founder badge via Alca https://discordapp.com/channels/325552783787032576/477487607379656716/631960904606547980

twitch.badges.founder.subscriber.js

client.on('message', (channel, tags, message, self) => {
    if(self) return;
    const { badges, 'badge-info': badgeInfo } = tags;
    let isSubscriber = false;
    let monthsSubbed = -1;
    if(badges) {
        isSubscriber = badges.subscriber || badges.founder;
        if(isSubscriber) {
            monthsSubbed = badgeInfo.subscriber || badgeInfo.founder;
        }
    }
    if(isSubscriber) {
        console.log(`${tags.username} is a subscriber for ${monthsSubbed} month(s).`);
    }
});