select.js

function getDomPath(el) {
    if (!el) {
      return;
    }
    var stack = [];
    var isShadow = false;
    while (el.parentNode != null) {
      // console.log(el.nodeName);
      var sibCount = 0;
      var sibIndex = 0;
      // get sibling indexes
      for ( var i = 0; i < el.parentNode.childNodes.length; i++ ) {
        var sib = el.parentNode.childNodes[i];
        if ( sib.nodeName == el.nodeName ) {
          if ( sib === el ) {
            sibIndex = sibCount;
          }
          sibCount++;
        }
      }
      // if ( el.hasAttribute('id') && el.id != '' ) { no id shortcuts, ids are not unique in shadowDom
      //   stack.unshift(el.nodeName.toLowerCase() + '#' + el.id);
      // } else
      var nodeName = el.nodeName.toLowerCase();
      if (isShadow) {
        nodeName += "::shadow";
        isShadow = false;
      }
      if ( sibCount > 1 ) {
        stack.unshift(nodeName + ':nth-of-type(' + (sibIndex + 1) + ')');
      } else {
        stack.unshift(nodeName);
      }
      el = el.parentNode;
      if (el.nodeType === 11) { // for shadow dom, we
        isShadow = true;
        el = el.host;
      }
    }
    stack.splice(0,1); // removes the html element
    return stack.join(' > ');
}

function getSelectedNode()
  {
      if (document.selection)
          return document.selection.createRange().parentElement();
      else
      {
          var selection = window.getSelection();
          if (selection.rangeCount > 0)
              return selection.getRangeAt(0).startContainer.parentNode;
      }
} 

var node_path = getDomPath(getSelectedNode());
chrome.runtime.sendMessage({type: "notification", options: { 
  type: "basic", 
  title: "path",
  message: node_path
}});