Politifact "Truthfulness" score

Politifact Truthfulness.user.js

// ==UserScript==
// @name         PolitiFact "Truthfulness"
// @match        https://www.politifact.com/personalities/*
// @updateUrl    https://gist.githubusercontent.com/Fordi/a46b9437859f5b613d863527abb8719f/raw/Politifact%2520Truthfulness.user.js
// ==/UserScript==

(function() {
  'use strict';
  const weights = [1, 0.75, 0.5, 0.25, 0, -0.5];
  const template = ({ sum, total }) => {
    const truth = Math.round(100 * sum / total);
    return `
      <li class="chartlist__item">
        <span class="chartlist__label">Truthfulness</span>
        <span class="chartlist__count">
          ${sum} / ${total} (${truth}%)
        </span>
        <span class="chartlist__index" style="width:${truth}%;">
          (${truth}%)
        </span>
      </li>
    `.trim();
  };
  const processChart = (chart) => {
    const elements = [].slice.call(chart.querySelectorAll('.chartlist__count'));
    if (elements.length === 7) { return; }
    const data = elements.reduce(({ sum, total }, el, index) => {
      const score = parseInt(el.textContent);
      console.log(score);
      return {
        sum: sum + score * weights[index],
        total: total + score,
      };
    }, { sum: 0, total: 0 });
    const div = document.createElement('div');
    div.innerHTML = template(data);
    div.querySelector('.chartlist__label').setAttribute('title', `
Aggregated score based on the weighted mean of evaulated statements.
Weights are:
True: 1.0
Mostly true: 0.75
Half-true: 0.5
Mostly false: 0.25
False: 0
Pants on Fire: -0.5
    `.trim());
    chart.appendChild(div.firstElementChild);
  }
  [].forEach.call(unsafeWindow.document.querySelectorAll('.chartlist'), processChart);
})();