How to write file to html with beauty?

I would like to write to the test.html file this html:

<h2><strong><a href="http://awesome.com">AwesomeCom</a></strong><span>is awesome</span></h2>

Which will be lokk like:

<h2>
    <strong>
        <a href="http://awesome.com">
            AwesomeCom
        </a>
    </strong>
    <span>
         is awesome
   </span>
</h2>

so it is looks beauty and so on...and i tried this code:

var html = require("html");
var beautify_html = require('js-beautify').html;
var data = '<h2><strong><a href="http://awesome.com">AwesomeCom</a></strong><span>is awesome</span></h2>';
var beautyHtml= beautify_html(data);
fs.writeFile('test.html',beautyHtml, function (err) {});

But it is stays in one line...is it wrong what i wrote? or i have to add something? Thanks for the helps

via kodaek98