How to use async or Promise.then()

[Josí de Mattos Neto]

How can I use gray-matter in a asynchronous way? It doesn't offer even a callback function (which would allow one to use utils.promisify).

[Brian Woodward]

gray-matter is synchronous so there is no need to use async or Promise.then().

[Josí de Mattos Neto]

Sorry, I think I didn't explained well: is there a way to use read function asynchronously?

I wish to use gray-matter in a Node.js application, which needs all file operations be performed asynchronously.

[Brian Woodward]

In that case, you could read the file in first, then pass it to gray-matter:

const fs = require('fs').promises;
const matter = require('gray-matter');

const read = async (filepath, options) {
  const str = await fs.readFile(filepath, 'utf8');
  const file = matter(str, options);
  file.path = filepath;
  return file;
};

The above will give you a .read method that looks like matter.read, but is async and can be used like:

const file = await read('./path/to/my-file.md');

If you just want to get the file object back "as-is" without adding the .path to it, you can also do something like this...

const filepath = './path/to/my-file.md';
const str = await fs.readFile(filepath, 'utf8');
const file = matter(str);