Amazon - Show absolute review numbers

Adds the number of reviews to each rating separately

You will need to install an extension such as Tampermonkey, Greasemonkey or Violentmonkey to install this script.

You will need to install an extension such as Tampermonkey to install this script.

You will need to install an extension such as Tampermonkey or Violentmonkey to install this script.

You will need to install an extension such as Tampermonkey or Userscripts to install this script.

You will need to install an extension such as Tampermonkey to install this script.

You will need to install a user script manager extension to install this script.

(I already have a user script manager, let me install it!)

You will need to install an extension such as Stylus to install this style.

You will need to install an extension such as Stylus to install this style.

You will need to install an extension such as Stylus to install this style.

You will need to install a user style manager extension to install this style.

You will need to install a user style manager extension to install this style.

You will need to install a user style manager extension to install this style.

(I already have a user style manager, let me install it!)

// ==UserScript==
// @name         Amazon - Show absolute review numbers
// @namespace    graphen
// @version      1.2.6
// @description  Adds the number of reviews to each rating separately
// @license      MIT
// @author       Graphen
// @include      /^https?:\/\/(www|smile)\.amazon\.(cn|in|co\.jp|sg|se|ae|fr|de|pl|it|nl|es|co\.uk|ca|com(\.(mx|au|br|tr|be))?)\/.*(dp|gp\/(product|video)|exec\/obidos\/ASIN|o\/ASIN|product-reviews)\/.*$/
// @grant        none
// @noframes
// @icon         https://www.amazon.com/favicon.ico
// ==/UserScript==

/* jshint esversion: 6 */

// Testpages:
// https://www.amazon.de/s?k=roccat+kone+pure+2017&__mk_de_DE=%C3%85M%C3%85%C5%BD%C3%95%C3%91&qid=1556553434&ref=sr_pg_1
// https://www.amazon.de/dp/B078S8YZZ6/

(function(doc) {
    'use strict';

    var totalReviewCount = doc.querySelector('[data-hook="total-review-count"]').innerText;
    var arrPercentages = Array.from(doc.querySelectorAll("#histogramTable .a-text-right"));

    if (totalReviewCount && arrPercentages) {
        // Sanitize totalReviewCount
        // Remove all non-digits
        totalReviewCount = totalReviewCount.replace(/\D/g, '');
        // Convert string to integer
        totalReviewCount = parseInt(totalReviewCount, 10);
        // Check for nonsense (Most reviewed product has ~100000 at the moment)
        if (totalReviewCount < 250000) {
            for (var e of arrPercentages) {
                let percentValue = e.innerText;
                // Get rid of percentage sign and convert string to integer
                percentValue = parseInt(percentValue, 10);
                // Calculate absolute review count
                percentValue = Math.round(percentValue * totalReviewCount / 100);
                // Cancel if nonsense
                if (percentValue > totalReviewCount || percentValue < 0) {
                    break;
                }
                // Append calculated value to visible node
                var absNum = doc.createTextNode(" (" + percentValue + ")");
                e.appendChild(absNum);
            }
        }
    }

    // Insert own stylesheet
    let reviewStyle = doc.createElement("style");
    reviewStyle.innerHTML = "#histogramTable td:last-of-type { text-align: right !important; }";
    doc.head.appendChild(reviewStyle);


})(document);