Basic JS for Drupal 8/9 project (module, theme)

myproject.js

window.Drupal = window.Drupal || { behaviors: {}, locale: {} };

(function ($, Drupal, settings) {

'use strict';

Drupal.myproject = {
  preInit: function() {},
  init: function(settings) {},
  postInit: function() {}
};
Drupal.behaviors.myproject = {
  attach: function (context, settings) {
  // DOM loaded
    Drupal.myproject.preInit();
    $(document, context).once('myprojectInit').each( function() {
    // Page ready -- with single run wrapper
      Drupal.myproject.init(settings);
      $(window).on('load', function() {
      // Page fully loaded
        Drupal.myproject.postInit();
      });
    });
  }
};
})(jQuery, Drupal, drupalSettings);