Use Gray-matter

Import gray-matter

const matter = require('gray-matter');

Pass a string to gray-matter.

console.log(matter('---\ntitle: Front Matter\n---\nThis is content.'));

Returns:

{
  content: '\nThis is content.',
  data: { 
    title: 'Front Matter' 
  } 
}

Example.

Create file file.html with the following content.

---
title: Hello
slug: home
---
<h1>Hello world!</h1>

Create file example.js with the following content.

const fs = require('fs');
const matter = require('gray-matter');
const str = fs.readFileSync('file.html', 'utf8');
console.log(matter(str));

Run in the terminal

node example 

As a result an object like this.

{
  content: '<h1>Hello world!</h1>',
  data: { title: 'Hello', slug: 'homes' },
  isEmpty: false,
  excerpt: ''
}

Reference Links

• https://www.npmjs.com/package/gray-matter