return a readFile fs code example

Example 1: nodejs readfile

const fs = require('fs');

fs.readFile('/Users/joe/test.txt', 'utf8' , (err, data) => {
  if (err) {
    console.error(err);
    return
  }
  console.log(data);
});

Example 2: fs readfile promise

var Promise = require('bluebird');
var fs = Promise.promisifyAll(require('fs'));

 function getImage(index) {
     var imgPath = __dirname + "/image1" + index + ".png";
     return fs.readFileAsync(imgPath);
 }