JSFiddle - React, Tailwind, and code Playground

JavaScript

var HTMLEntities = function(str){
	var str = String(str), chars = {
  		'&':'&',
      '"':'"',
      '<':'&lt;',
      '>':'&gt;'
  }
  for (var i in chars) 
  		str=str.replace(new RegExp(i,'g'), chars[i]);
   return str;
};


document.getElementsByTagName('html')[0].innerHTML = HTMLEntities("<h1<img src=this.src onerror=alert('fuuuuck');>>test</</h1>h1>");