(I actually think I found some answers from Webpacker presents a more difficult OOB experience for JS Sprinkles than Sprockets did).
We have two platforms. Both rails 5 and we are currently migrating them to rails 6. We would like to share a common “feature” between the two. Feature is - upload file, process it, show some result. There are css, js, images, a controller.
My question is, in the long run - next 4-5 years, what is the recommended way to reuse the js? What should we aim for? Guidance would be very helpful.
With a rails engine we can reuse the controller.
With a rails engine and sprockets we can reuse css, images,
But for the js it is not clear - I read more and more about moving the js entirely to npm and getting it with webpack. People share that you should even try skipping webpacker and us directly webpack. (source - How to include JS from gems? · Issue #57 · rails/webpacker · GitHub, How to use this gem from within rails engines? · Issue #348 · rails/webpacker · GitHub). But there is also the webpacker engine support which people seem to get working, but have issues with (again - the above two threads).
Rails 6 recommends webpacker for js and sprockets for others, but if we have to manage a gem and a npm package we are probably better of just moving everything in the npm package - css, images, js.
There are no guides about this on https://guides.rubyonrails.org/.
Should we even aim for keeping any js in gems/engines or we should move all of it to npm even when it makes no sense (as this js makes no sense without the view, controller, css, images)?