lib/cache_helper.js
/**
 * CacheHelper is used to cache information
 * in order to compare 2 version of screenshots
 *
 * The JSON format of element in the "screenshots" array is:
 * {
 *   description: 'image description',
 *   image_a: 'file path of first version screenshot',
 *   image_b: 'file path of second version screenshot',
 *   image_diff:  'file path of diff result',
 * }
 *
 */
CacheHelper is used to cache information
in order to compare 2 version of screenshots


CacheHelper is used to cache information in order to compare 2 version of screenshots
function CacheHelper() {
  this.screenshots = [];
  this.path = '';
  this.version_a = '';
  this.version_b = '';
  imageHelper = new ImageHelper();
}
function CacheHelper ( ) { this . screenshots = [ ] ; this . path = '' ; this . version_a = '' ; this . version_b = '' ; imageHelper = new ImageHelper ( ) ; }
CacheHelper is used to cache information
 in order to compare 2 version of screenshots
CacheHelper is used to cache information in order to compare 2 version of screenshots