Facebook Marketplace item hider

FBMarketplaceHider.user.js

// ==UserScript==
// @name        Facebook Marketplace Item Hider
// @namespace   FBMarkerplaceHider
// @match       *://www.facebook.com/marketplace/*
// @grant       GM_setValue
// @grant       GM_getValue
// @version     1.0
// @author      Ergo Enn
// @description On right-click allows to hide item in Facebook Marketplace
// @downloadURL  https://gist.github.com/ErgEnn/
// @updateURL    https://gist.github.com/ErgEnn/
// ==/UserScript==

(function () {
  'use strict';

  let hiddenItems = new Set(JSON.parse(GM_getValue('hiddenItems', '[]')));

  function hideElement(elem) {
    if (elem) {
      elem.style.opacity = 0.1;
    }
  }

  function extractItemId(href) {
    const match = href.match(/item\/(\d+)/);
    return match ? match[1] : null;
  }

  function hideMarketplaceItem(event) {
      if(confirm("Hide?")){
          event.preventDefault();
      }else{
          return;
      }
    const closestAnchor = event.target.closest('a');
    if (!closestAnchor) return;

    const itemId = extractItemId(closestAnchor.href);
    if (!itemId) return;

    let targetElement = closestAnchor;
    for (let i = 0; i < 6; i++) {
      if (targetElement.parentNode) {
        targetElement = targetElement.parentNode;
      } else {
        break;
      }
    }

    hiddenItems.add(itemId);
    GM_setValue('hiddenItems', JSON.stringify(Array.from(hiddenItems)));
    hideElement(targetElement);
  }

  function checkAndHideStoredItems() {
    document.querySelectorAll('a').forEach(anchor => {
      const itemId = extractItemId(anchor.href);
      if (itemId && hiddenItems.has(itemId)) {
        let targetElement = anchor;
        for (let i = 0; i < 6; i++) {
          if (targetElement.parentNode) {
            targetElement = targetElement.parentNode;
          } else {
            break;
          }
        }
        hideElement(targetElement);
      }
    });
  }

  new MutationObserver(checkAndHideStoredItems).observe(document.body, {
    childList: true,
    subtree: true
  });

  document.addEventListener('contextmenu', hideMarketplaceItem);
})();