TamperMonkey script for jumping to failed tests in Semaphore build output by clicking on red "Failed in ..." button

Semaphore jump to FAILED v2.user.js

// ==UserScript==
// @name         Semaphore jump to FAILED
// @namespace    http://tampermonkey.net/
// @version      0.1
// @description  try to take over the world!
// @author       You
// @match        https://nedap.semaphoreci.com/jobs/*
// @grant        GM_addStyle
// ==/UserScript==
// https://gist.github.com/dannylagrouw/3e7d528b15b069e879e909424af4d8fb

(function() {
    'use strict';

    var lastPos = 0;

    window.addEventListener('load', function() {
        GM_addStyle('.myButton {' +
                    '    box-shadow: 3px 4px 11px 1px #8a2a21;' +
                    '    background:linear-gradient(to bottom, #c62d1f 5%, #f24437 100%);' +
                    '    background-color:#c62d1f;' +
                    '    border-radius:42px;' +
                    '    border:9px solid #d02718;' +
                    '    display:inline-block;' +
                    '    cursor:pointer;' +
                    '    color:#ffffff;' +
                    '    font-family:Arial;' +
                    '    font-size:17px;' +
                    '    font-weight:bold;' +
                    '    padding:7px 25px;' +
                    '    text-decoration:none;' +
                    '    text-shadow:0px 1px 0px #810e05;' +
                    '}' +
                    '.myButton:hover {' +
                    '    background:linear-gradient(to bottom, #f24437 5%, #c62d1f 100%);' +
                    '    background-color:#f24437;' +
                    '}' +
                    '.myButton:active {' +
                    '    position:relative;' +
                    '    top:1px;' +
                    '}' +
                    '.myButton:focus {' +
                    '    outline:none;' +
                    '}');

        window.setTimeout(function() {
            document.querySelector('#job-log-container').style.height = '67vh';
        }, 500);
        // var jobstate = document.getElementById('job-state');
        // var jobstate = document.querySelector('#main-content .pollman-container .f7')
        var button = document.createElement('button');
        button.innerText = 'Next Error';
        button.className = 'myButton';
//        button.style.backgroundColor = '#e53935';
//        button.style.color = 'white';
        document.querySelector('#main-content h1').insertAdjacentElement('afterend', button);

        button.addEventListener('click', function() {
            // var faileds = Array.from(document.querySelectorAll('#log-table td.output span'))
            var faileds = Array.from(document.querySelectorAll('#job-log .job-log-line-body > span'))
            .filter(
                function(e) {
                    return e.innerText.endsWith(' FAILED');
                });
            faileds.forEach(function(e) {
                e.parentElement.style.color = 'white';
                e.parentElement.style.backgroundColor = '#e53935';
            });
            button.innerText = 'Next Error (' + (lastPos + 1) + '/' + faileds.length + ')';
            // var logContainer = document.getElementById('log-container');
            var logContainer = document.getElementById('job-log');
            var containerPos = logContainer.scrollTop;
            if (faileds && faileds.length > 0) {
                faileds[lastPos].scrollIntoView({smooth: true, block: 'center'});
                if (faileds.length > lastPos + 1) {
                    lastPos++;
                } else {
                    lastPos = 0;
                }
            }
        });
    }, false);
})();