DOM patching without: provide two DOM elements, the second (and contents) will be modified such that it resembles the first

patdj.js

function patdj(target, update, preserve = true) {
  if (update.nodeType != 1 && update.nodeType == target.nodeType)
    target.nodeValue = update.nodeValue

  else if (update.nodeType != target.nodeType || update.tagName !== target.tagName || update.type !== target.type){
    const { nextSibling, parentNode } = target;
    const replacement = preserve ? update.cloneNode(true) : update;

    parentNode.removeChild(target);


    if (nextSibling) 
      parentNode.insertBefore(replacement, nextSibling);

    else 
      parentNode.appendChild(replacement);
  }

  else {
    const properties = new Set();

    for (const key in update)
      properties.add(key);

    for (const key in target)
      properties.add(key);

    for (const key of properties)
      if (!(key in update)) 
        delete target[key];

      else if (update[key] !== target[key] && !isNaN(update[key]))
        target[key] = update[key];

    for (const key of new Set(
      [...update.attributes, ...target.attributes].map(({ name }) => name)
    ))
      if (!update.hasAttribute(key)) 
        target.removeAttribute(key);

      else {
        const value = update.getAttribute(key);

        if (value !== target.getAttribute(key)) 
          target.setAttribute(key, value);
      }

    let index = Math.max(update.childNodes.length, target.childNodes.length);

    while (index-- > 0){
      if (!update.childNodes[index]) 
        target.removeChild(target.childNodes[index]);

      else 
        patdj(update.childNodes[index], target.childNodes[index]);
    }
  }
}

Revision 5 introduced sub-tree node patching at the expense of property patching