utils.js

const fs = require('fs')
const path = require('path')

/**
 * Parse a base 64 image and return the extension and buffer
 * @param  {String} imageString The image data as base65 string
 * @return {Object}             { type: String, data: Buffer }
 */
function parseBase64Image(imageString) {
  var matches = imageString.match(/^data:image\/([A-Za-z-+/]+);base64,(.+)$/);
  var resource = {};

  if (matches.length !== 3) {
    return null;
  }

  resource.type = matches[1] === 'jpeg' ? 'jpg' : matches[1];
  resource.data = new Buffer(matches[2], 'base64');
  return resource;
}


function random (low, high) {
    return Math.random() * (high - low) + low;
}

function getImageType(data) {
  if(data.indexOf("jpg") !== -1) return 'jpg'
  else if (data.indexOf("jpeg") !== -1) return 'jpeg'
  else if(data.indexOf("png") !== -1) return 'png'
  return null
}

/**
 * Remove directory recursively
 * @param {string} dir_path
 * @see https://stackoverflow.com/a/42505874/3027390
 */
function rimraf(dir_path) {
    if (fs.existsSync(dir_path)) {
        fs.readdirSync(dir_path).forEach(function(entry) {
            var entry_path = path.join(dir_path, entry);
            if (fs.lstatSync(entry_path).isDirectory()) {
                rimraf(entry_path);
            } else {
                fs.unlinkSync(entry_path);
            }
        });
        fs.rmdirSync(dir_path);
    }
}

module.exports = {
  parseBase64Image,
  random,
  getImageType,
  rimraf
}