Script to grab existing meta data on a webpage in a data structure consumable by react-helmet

metadata.js

function _toConsumableArray(arr) { if (Array.isArray(arr)) { for (var i = 0, arr2 = Array(arr.length); i < arr.length; i++) { arr2[i] = arr[i]; } return arr2; } else { return Array.from(arr); } }

var s = document.createElement('script');
s.type = 'text/javascript';
s.src = 'https://code.jquery.com/jquery-3.1.1.min.js';
var x = document.getElementsByTagName('script')[0];
x.parentNode.insertBefore(s, x);

var f = document.createElement('script');
f.type = 'text/javascript';
f.src = 'https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.4/lodash.min.js';
var x = document.getElementsByTagName('script')[0];
x.parentNode.insertBefore(f, x);

setTimeout(function () {
  var metaList = $('head').find('meta').map(function (i, node) {
    var obj = {};
    [].concat(_toConsumableArray(node.attributes)).map(function (attr) {
      obj[attr.name] = attr.value;
      return obj;
    });
    return obj;
  });

  var uniqList = _.chain(metaList).map(JSON.stringify).uniq().map(JSON.parse).value();

  console.log(JSON.stringify(uniqList, 2, 2));
}, 3000);