Using callback

const fs = require('fs');

const path = './file.txt';

fs.access(path, (error, stats) => {
  if (error) {
    console.error(error);
  } else {
    console.log(stats);
  }
});

Using util.promisify

Node v8.0.0 added support for a built-in util.promisify.

const fs = require('fs');
const { promisify } = require('util');

const path = './file.txt';

// Convert `fs.access()` into a function that returns a promise
const accessAsync = promisify(fs.access);

(async () => {
   try {
    const stats = await accessAsync(path);

    console.log(stats);
   } catch (error) {
    console.error(error);
   }
})();

Using fs.promises

The fs.promises API provides an alternative set of asynchronous file system methods that return Promise objects rather than using callbacks.

Node v10.0.0 added support for a built-in util.promisify.

const fsPromises = require('fs').promises; // Alternatively, you can import fs with require('fs/promises')

const path = './file.txt';

(async () => {
   try {
    const stats = await fsPromises.stat(path);

    console.log(stats);
   } catch (error) {
    console.error(error);
   }
})();
fs