How do I format JQuery in Drupal 8?

Question

I'm trying to write a simple JQuery function in order to animate my mobile navigation. However, I'm not sure how to format the .js file. I've looked up some examples online, but I couldn't get my function to work, when I tried to use the example templates. Here's what I'm currently using, which works in Chrome, but FireFox logs an error, which I'll also post below:

My code:

(function ($, Drupal) {
      $(function(){
        $( '#mobile-menu-toggle-button' ).click(function(){
          $( '.mobile-menu-toggle' ).toggleClass( "open" );
        });
        $( '.overlay' ).click(function(e){
          if(e.target != this) return;
          $( '.mobile-menu-toggle' ).toggleClass( "open" );
        });
      });
})(jQuery, Drupal);

FireFox errors:

ReferenceError: Drupal is not defined

I'm thinking my formatting is off. Any help would be greatly appreciated.

Answer 1

D8 makes fewer assumptions about what you need in the page, so the Drupal JS library isn't included unless it's specified.

Just add

- core/drupal

as one of your library's dependancies, rebuild the cache, and all should be well.