AliExpress: cart: 'real shipping' = shipping - 'shipping saved'

saved-shipping.aliexpress.tamper.js

// ==UserScript==
// @name         AliExpress: cart: 'real shipping' = shipping - 'shipping saved'
// @namespace    https://gist.github.com/vogler
// @downloadURL  https://gist.github.com/vogler/41f0b6a5bead9e4670dc9c9b30454a0e/raw/saved-shipping.aliexpress.tamper.js
// @version      0.2
// @description  Show the real shipping cost, i.e. minus the shared/saved shipping. Without this it's hard to optimize shipping since there also might be other savings.
// @author       Ralf Vogler
// @match        https://shoppingcart.aliexpress.com/shopcart/*
// @grant        none
// ==/UserScript==

(function() {
  'use strict';

  const num = el => parseFloat(el.innerText.match(/\d+\.\d+/));

  const f = t => {
    // console.log('target', t);
    if (t.className != 'next-loading-masker') return;
    const el = document.querySelector('#shoppingcart-price');
    const shipping = num(el.querySelectorAll('.charges-totle dd')[1]);
    const savings = el.querySelectorAll('.charges-detail dl');
    let real = shipping;
    for (const x of savings) {
      const [dt, dd] = x.children;
      if (dt.innerText.match(/Shipping +saved/)) {
        const saved = num(dd);
        real = (shipping - saved).toFixed(2);
        console.log(shipping, saved, real);
      }
    }
    // beware infinite mutation-observer-loop! need to only set text if it's different.
    const shipping_el = el.querySelectorAll('.charges-totle dt')[1];
    const check_set = s => { if (shipping_el.innerText != s) shipping_el.innerText = s };
    check_set(`Shipping (eff. ${real})`);
  }

  // handle dynamically loaded/changed items
  // the #shoppingcart-price we want to observe is not there initially, so we try until it exists
//   const tryUntil = (f, a, c, t=200, n=5) => {
//     const r = f.apply(this, [a]);
//     if (r) c.apply(this, [r]);
//     else if (n) window.setTimeout(() => tryUntil(f,a,c,t,n-1), t)
//   }
  const observe = (n) => {
    const id = '#price-overview';
    const target = document.querySelector(id);
    if (target) {
      console.log(`${id} found!`);
      (new MutationObserver((ms, ob) =>
        ms.forEach(m => {
          // console.log(m);
          m.removedNodes.forEach(f);
        })
      )).observe(target, { childList: true, subtree: true });
    } else if (n) {
      console.log(`${id} not yet found`);
      window.setTimeout(() => observe(n-1), 100);
    }
  };
  observe(10);
})();