Fast machine names for Drupal 8 - hacky

fast_machine_names.js

(function ($, Drupal) {
  delete Drupal.behaviors.machineName.transliterate;

  Drupal.behaviors.machineName.transliterate = function(str) {
    var transliterated = str.replace(' ', '_').replace(/[^\w]+/g,'').toLowerCase();
    var deferred = $.Deferred();
    var promise = deferred.promise();
    deferred.resolve(transliterated);
    promise.abort = function() {};
    return promise;
  }

})(jQuery, Drupal);

fast_machine_names.libraries.yml

fast_machine_names:
  version: 0.5
  js:
    fast_machine_names.js: {}
  dependencies:
    - core/drupal.machine-name

fast_machine_names.module

<?php

function fast_machine_names_form_field_ui_field_storage_add_form_alter(&$form, \Drupal\Core\Form\FormStateInterface $form_state, $form_id) {
  $form['new_storage_wrapper']['field_name']['#attached']['library'][] = 'fast_machine_names/fast_machine_names';
}