github-notification-count.tapermonkey.js

// ==UserScript==
// @name         GitHub notification-count
// @version      1.0
// @namespace    http://tampermonkey.net/
// @description  Shows the amount of notifications
// @match        https://*.github.com/*
// @grant        none
// @run-at       document-start
// ==/UserScript==

!async function () {
    async function queryAsync(query) {
        return new Promise(resolve => {
            const interval = setInterval(() => {
                const element = document.querySelector(query);
                if (element) {
                    clearInterval(interval);
                    return resolve(element);
                }
            }, 1000);
        });
    }

    queryAsync('.logged-in').then(() => {
        return fetch('https://github.com/notifications', {
            credentials: 'include'
        });
    }).then(v => v.text()).then(body => {
        const dom = (new DOMParser()).parseFromString(body, 'text/html');
        return dom.querySelector('.filter-item .count').innerHTML;
    }).then(async count => {

        if (!Number(count)) {
            return;
        }

        // Update notification knob
        const notificationIcon = await queryAsync('.mail-status.unread');
        notificationIcon.innerHTML = count;
        Object.assign(notificationIcon.style, {
            width: 'auto',
            height: 'auto',
            fontSize: '9px',
            fontWeight: '700',
            padding: '0.1em 0.45em',
            display: 'inline-block',
            borderRadius: '100em'
        });

        // Update title
        const [, , raw] = document.title.match(/^(\([\d ]+\)|)(.*)/);
        document.title = `(${count}) ${raw}`;
    });
}();