Hide facebook sponsored ads.js

const observeDOM = (function() {
  const MutationObserver = window.MutationObserver ||
      window.WebKitMutationObserver;

  return function(obj, callback) {
    if (!obj || obj.nodeType !== 1) return;

    if (MutationObserver) {
      // define a new observer
      const mutationObserver = new MutationObserver(callback);

      // have the observer observe foo for changes in children
      mutationObserver.observe(obj, {childList: true, subtree: true});
      return mutationObserver;
    }

    // browser support fallback
    else if (window.addEventListener) {
      obj.addEventListener('DOMNodeInserted', callback, false);
      obj.addEventListener('DOMNodeRemoved', callback, false);
    }
  };
})();

observeDOM(document.body, m => {
  m.forEach(e => {
    if (!e.addedNodes.length) {
      return;
    }

    const nodes = e.addedNodes;
    nodes.forEach(node => {
      if (!node.getAttribute || !node.getAttribute('data-pagelet')) {
        return true;
      }

      const match = 'Sponsored';

      const a = node.querySelectorAll('a > span');
      a.forEach(span => maybeHideThis(span, match));
    });
  });
});

function maybeHideThis(node, text) {
  const theText = getTextRecursive(node).join('');
  console.log(theText);
  if (theText === text) {
    const wrapper = node.closest('[data-pagelet]');
    if (wrapper) {
      wrapper.style.display = 'none';
    }
  }
}

function getTextRecursive(node) {
  if (node.nodeType === 3) {
    return node.textContent;
  }
  const children = node.childNodes;
  if (!children.length) {
    return '';
  }
  const r = [];
  for (let i = 0; i < children.length; i++) {
    if (children[i].style && (children[i].style.display === 'none' || children[i].style.position === 'absolute')) {
      continue;
    }
    r[i] = getTextRecursive(children[i]);
  }
  return r.flat();
}