https://www.peluchesetjouetsenbois.fr/wp-content/plugins/generateperf/js/progress-bar.js?ver=2.8.6

1const progressJS = {
2  defaults: {
3    attach: null,
4    round: 2
5  },
6  start: function(configs = {}) {
7    const { attach: attachSelector, round: roundto } = { ...this.defaults, ...configs };
8    const progressJSelem = document.createElement("div");
9    progressJSelem.classList.add("progress-bar");
10    document.body.appendChild(progressJSelem);
11    const attachElem = attachSelector ? document.querySelector(attachSelector) : null;
12    const maxHeight = document.body.scrollHeight;
13    const sizeHeight = window.innerHeight;
14    let formattedPercentage;
15    function updateProgressBar() {
16      const scrolls = window.scrollY;
17      const percentageValue = (scrolls / (maxHeight - sizeHeight)) * 100;
18      formattedPercentage = percentageValue.toFixed(roundto);
19      progressJSelem.style.width = `${formattedPercentage}%`;
20      if (attachElem) {
21        attachElem.textContent = formattedPercentage;
22      }
23      requestAnimationFrame(updateProgressBar);
24    }
25    requestAnimationFrame(updateProgressBar);
26  }
27}
28progressJS.start();