JSFiddle - React, Tailwind, and code Playground

HTML

<div class="main">
    <ul class=" list of things">
        <li><a href="moo" class="link">lol</a></li>
    </ul>
</div>

JavaScript

function getSelector(element) {
      var selector = element.id;

      // if we have an ID, that's all we need. IDs are unique. The end.
      if(selector.id) { return "#" + selector; }

      selector = [];
      var cl;
      while(element.parentNode) {
        cl = element.getAttribute("class");
        cl = cl ? "." + cl.trim().replace(/ +/g,'.') : '';
        selector.push(element.localName + cl);
        element = element.parentNode;
      }
      return selector.reverse().join(' ');
    }

var a = document.querySelector("a");
console.log(getSelector(a));