A module that returns a selector string for a DOM node.

get-selector.js

// Cribbed this from:
// https://web.dev/debug-web-vitals-in-the-field/#usage-with-the-web-vitals-javascript-library
export function getSelector(node, maxLen = 100) {
  let sel = '';

  try {
    while (node && node.nodeType !== 9) {
      const part = node.id ? '#' + node.id : node.nodeName.toLowerCase() + (
        (node.className && node.className.length) ?
        '.' + Array.from(node.classList.values()).join('.') : '');

      if (sel.length + part.length > maxLen - 1) {
        return sel || part;
      }

      sel = sel ? part + '>' + sel : part;

      if (node.id) {
        break;
      }

      node = node.parentNode;
    }
  } catch (e) {
    // Do nothing.
  }

  return sel;
}