title: how to use js files from Gem in rails 6 application
body: <p>So I have been using rails for quite a while.  But with Rails 6 I have been really struggling to get moving.  I have some custom gems I use for assets and things and I cannot figure out how to load the js files.</p>
  
  <p>What I am used to</p>
  
  <p>application.js</p>
  
  <pre><code>//= require activestorage
  //= require jquery-3.3.1.min
  //= require popper.min
  //= require bootstrap
  //= require mdb
  //= require wysiwyg
  //= require addons/pickr.min
  //= require modules/buttons
  //= require modules/cards
  //= require modules/waves
  //= require activestorage
  //= require turbolinks
  //= require_tree .
  </code></pre>
  
  <p>But this does not load in Rails 6 with Webpacker.  I was unable to find a basic solution online for this that did not involve adding multiple js files and lines of code to the app to patch a solution together.  What I did try was</p>
  
  <p>app/javascript/packs/application.js</p>
  
  <pre><code>require("@rails/ujs").start()
  require("turbolinks").start()
  require ("jquery-3.3.1.min").start()
  require ("popper.min").start()
  require ("bootstrap").start()
  require ("mdb").start()
  require ("wysiwyg").start()
  require ("addons/pickr.min").start()
  require ("modules/buttons").start()
  require ("modules/cards").start()
  require ("modules/waves").start()
  require("@rails/activestorage").start()
  require("channels")
  </code></pre>
  
  <p>The assets are in the correct place inside the gem (so the first version in a rails 5 app does load everything as expected).  I can add some of these with yarn, but I want to use the actual files from the gem, not just get bootstrap working, is there a straightforward solution to this?  I also tried adjusting the path in the <code>require</code> but that did not work either.</p>
  
  <p>Thanks for any help!</p>