code: function findAllCompressionFiles(fs, folderPath) {
          // check if folder exists
          if (!fs.existsSync(folderPath))  return; 
          
          var files = fs.readdirSync(folderPath);
          //iterate all files in the current folder
          for (var i = 0; i < files.length; i++) {
              var filePath = folderPath + "/" + files[i];
              var stats = fs.statSync(filePath);
              if (stats.isDirectory()) {
                  //recursively search folders and append the matching files
                  findAllCompressionFiles(fs, filePath);
              } else {
                  addAllMatchingCompressionsToFile(files[i], filePath);
              }
          }
      }
docs: Picks all files into the matching compression's file list. Search is done recursively!
  @param {Object} fs: node.fs
  @param {string} folderPath