index.js

var sendToContentful = (fileSend)=>{
  var name = '';
  var data = {};
  var names = {};
  var addEntryToData = (pathname)=>{
    var filename = path.basename(pathname);

    var longlocale = filename.substr(0,5);
    if(exactMatches.indexOf(longlocale.toUpperCase()) != -1){

      names[longlocale] = filename.substr(5);
      data[longlocale] = {
        contentType: mime.lookup(filename),
        fileName: filename,
        file: fs.createReadStream(pathname)
      }

      console.log(names, data);
    }else{      
      var locale = filename.substr(0,2).toUpperCase();
      for(var a in localeNames[locale]){
        names[localeNames[locale][a]] = filename.substr(3);
        data[localeNames[locale][a]] = {
          contentType: mime.lookup(filename),
          fileName: filename,
          file: fs.createReadStream(pathname)
        }
      }
    }
  }
  
  for(var a in fileSend){
    addEntryToData(fileSend[a]);
  }
  console.time('UPLOAD')

  client.getSpace(space)
  .then((space) => space.createAssetFromFiles({fields: { title: names, file: data }}))  
  .then((asset) => {
    asset.processForAllLocales(); 
    console.log(asset); 
    console.timeEnd('UPLOAD')
  })
  .then((asset) => {
    console.groupEnd('Uploading');
    console.timeEnd('Time')
  })
  .catch(console.error)
}


var folderWithFiles = process.argv[2];
var walkSync = function(dir, filelist) {  
  files = fs.readdirSync(dir);
  filelist = filelist || [];
  files.forEach(function(file) {
    if (fs.statSync(dir + file).isDirectory()) {
      filelist = walkSync(dir + file + '/', filelist);
    }
    else {
      filelist.push(file);
    }
  });
  return filelist;
};


var list = walkSync(folderWithFiles);

for (var i = list.length - 1; i >= 0; i--) {
  if(list[i].match('desktop')){
    files.desktop.push(folderWithFiles+'/'+list[i]);
  }
  if(list[i].match('tablet_v')){
    files.tablet_v.push(folderWithFiles+'/'+list[i]);
  }
  if(list[i].match('tablet_h')){
    files.tablet_h.push(folderWithFiles+'/'+list[i]);
  }
  if(list[i].match('mobile')){
    files.mobile.push(folderWithFiles+'/'+list[i]);
  }
}

if(files.desktop.length){
  sendToContentful(files.desktop);      
}
if(files.tablet_h.length){
  sendToContentful(files.tablet_h);
}
if(files.tablet_v.length){
  sendToContentful(files.tablet_v);
}
if(files.mobile.length){
  sendToContentful(files.mobile);
}