Javascript Mustache invalid template on code

I am working on an application and I have install mustache via npm.

Then in my main.js file I imported it like this:

const Mustache = require('mustache')

I then have a html template file with this:

<title></title> in the tile part of the html file.

Using node I've then loaded the template file and tried to run render.

Here's the code:

fs.readFile('template.html', (err, data) => {

  var mydata = Mustache.render(data, {title: "sometitle"});

  fs.writeFile('result.html', mydata, (err) => {

    if (err) throw err;
    console.log('The file has been saved!');

  });

}); 

I keep getting this error:

TypeError: Invalid template! Template should be a "string" but "object" was given as the first argument for mustache#render

How can I fix this so I can change and save the result?

via dj2017