asciimike

// set it up
firebase.storage().ref().constructor.prototype.putFiles = function(files) { 
  var ref = this;
  return Promise.all(files.map(function(file) {
    return ref.child(file.name).put(file);
  }));
}

// use it!
firebase.storage().ref().putFiles(files).then(function(metadatas) {