Native JavaScript or ES6 way to encode and decode HTML entities?

There is no native function in the JavaScript API that convert ASCII characters to their "html-entities" equivalent. Here is a beginning of a solution and an easy trick that you may like

A nice function using es6 for escaping html:

const escapeHTML = str => str.replace(/[&<>'"]/g, 
  tag => ({
      '&': '&amp;',
      '<': '&lt;',
      '>': '&gt;',
      "'": '&#39;',
      '"': '&quot;'
    }[tag]));