JSFiddle - React, Tailwind, and code Playground

HTML

<console/>

JavaScript

var text = [
    "<div>Test</div>",
    "<div>Test</div><div>ds",
    "<div>Test</div><br/>ds<br />",
    "</a>",
    "<br/>",
    "fssdfg"
];

var regex = /^(?:<(\w+)(?:(?:\s+\w+(?:\s*=\s*(?:".*?"|'.*?'|[^'">\s]+))?)+\s*|\s*)>[^<>]*<\/\1+\s*>|<\w+(?:(?:\s+\w+(?:\s*=\s*(?:".*?"|'.*?'|[^'">\s]+))?)+\s*|\s*)\/>|<!--.*?-->|[^<>]+)*$/;

var console=$('console');
console.log=function(msg) {
   this.append(msg+'<br>');
};

var len=text.length;
for(var i=0;i<len;i++) {
    console.log(escapeHtml(text[i]) + ' : <b>' + regex.test(text[i]) + '</b>');
}

function escapeHtml(code) {
    return code.replace(/&/g, "&amp;").replace(/</g, "&lt;").replace(/>/g, "&gt;");
}