code: async function readFileAsync(...args) {
    return new Promise((resolve, reject) => {
      fs.readFile(...args, (err, result) => {
        if (err) {
          reject(err);
        } else {
          resolve(result);
        }
      });
    });
  }
docs: Promise interface for `fs.readFile`
  
  @param {<string> | <Buffer> | <URL> | <integer>} p filename or file descriptor
  @param {<Object> | <string>} options