how to use js files from Gem in rails 6 application - ruby-on-rails

Question

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.
What I am used to
application.js
//= 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 .
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
app/javascript/packs/application.js
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")
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 require but that did not work either.
Thanks for any help!

Answer 1

You need to import js files via gem. Maybe this can help you:
import jQuery from 'jquery'
<%= File.read(File.join(Gem.loaded_specs['bla_bla_gem'].full_gem_path, 'lib', 'assets', 'javascripts', 'bla_bla.js')) %>
Related issue comment

Answer 2

So to answer in rails 6 you will notice the use of the javascript folder app/javascript this means that anything you do with JS should be done from there. The reliance on gems for these is now minimal and replaced by yarn.
I will give you an example of my process for using js libraries. for the example i will call bootstrap using yarn. I have included the custom files to help you call each library.
this is a process I like to use which I have modified from something i read on medium a while back
# app/javascript/packs/application.js
import '../stylesheets/application'
# app/views/layouts/application.html.erb
<%= stylesheet_pack_tag 'application', media: 'all', 'data-turbolinks-track': 'reload' %>
<%= javascript_pack_tag 'application', 'data-turbolinks-track': 'reload' %>
in the console run
yarn add bootstrap#4.3.1 jquery popper.js
then
# config/webpack/environment.js
...
const webpack = require('webpack')
environment.plugins.append(
'Provide',
new webpack.ProvidePlugin({
$: 'jquery',
jQuery: 'jquery',
Popper: ['popper.js', 'default']
})
)
...
then
# app/javascript/packs/bootstrap_custom.js
import 'bootstrap/js/dist/alert'
import 'bootstrap/js/dist/button'
import 'bootstrap/js/dist/carousel'
import 'bootstrap/js/dist/collapse'
import 'bootstrap/js/dist/dropdown'
import 'bootstrap/js/dist/index'
import 'bootstrap/js/dist/modal'
import 'bootstrap/js/dist/popover'
import 'bootstrap/js/dist/scrollspy'
import 'bootstrap/js/dist/tab'
import 'bootstrap/js/dist/toast'
import 'bootstrap/js/dist/tooltip'
import 'bootstrap/js/dist/util'
And link it in your app/javascript/packs/application.js file.
# app/javascript/packs/application.js
import './bootstrap_custom.js'
then
# app/javascript/stylesheets/application.scss
#import './bootstrap_custom.scss'
then
# app/javascript/stylesheets/bootstrap_custom.scss
#import '~bootstrap/scss/_functions.scss';
#import '~bootstrap/scss/_variables.scss';
#import '~bootstrap/scss/_mixins.scss';
#import '~bootstrap/scss/_root.scss';
#import '~bootstrap/scss/_reboot.scss';
#import '~bootstrap/scss/_type.scss';
#import '~bootstrap/scss/_alert.scss';
#import '~bootstrap/scss/_badge';
#import '~bootstrap/scss/_breadcrumb';
#import '~bootstrap/scss/_button-group';
#import '~bootstrap/scss/_buttons';
#import '~bootstrap/scss/_buttons.scss';
#import '~bootstrap/scss/_card.scss';
#import '~bootstrap/scss/_carousel.scss';
#import '~bootstrap/scss/_close.scss';
#import '~bootstrap/scss/_code.scss';
#import '~bootstrap/scss/_custom-forms.scss';
#import '~bootstrap/scss/_dropdown.scss';
#import '~bootstrap/scss/_forms.scss';
#import '~bootstrap/scss/_grid.scss';
#import '~bootstrap/scss/_images.scss';
#import '~bootstrap/scss/_input-group.scss';
#import '~bootstrap/scss/_jumbotron.scss';
#import '~bootstrap/scss/_list-group.scss';
#import '~bootstrap/scss/_media.scss';
#import '~bootstrap/scss/_modal.scss';
#import '~bootstrap/scss/_nav.scss';
#import '~bootstrap/scss/_navbar.scss';
#import '~bootstrap/scss/_pagination.scss';
#import '~bootstrap/scss/_popover.scss';
#import '~bootstrap/scss/_print.scss';
#import '~bootstrap/scss/_progress.scss';
#import '~bootstrap/scss/_spinners.scss';
#import '~bootstrap/scss/_tables.scss';
#import '~bootstrap/scss/_toasts.scss';
#import '~bootstrap/scss/_tooltip.scss';
#import '~bootstrap/scss/_transitions.scss';
#import '~bootstrap/scss/_utilities.scss';
If you choose to follow this follow it precisely, do not change the scss lines etc it will mess it up

Answer 3

You'll need to get them directly from the gem files.
Change your application.js to application.js.erb and follow demir solution. You can also use the next to import more than one file.
<% ['file_1', 'file_2'].each do |file| %>
import "<%= File.join(Gem.loaded_specs['my_gem'].full_gem_path, 'app', 'assets', 'javascripts', file) %>";
<% end %>

Answer 4

I think the location of file may be creating an issue for your case:
File should be in app/assets/javascripts/application.js while the your file is in
app/javascript/packs/application.js
Hope this will help you.