This is a simple gem which will call webpack-cli to compile designated js files ( including dependent modules ) within the standard sprockets asset pipeline.

gem install sprockets-webpackit

requires node.js to be installed along with webpack, webpack-cli and any other node modules you require. ( eg coffeescript , truescript , etc )

npm install webpack webpack-cli --save-dev

create a webpack.config.js to control the compilation process.

tested with:

webpack:  version 4.44.1
node:     version 12.13.0

require 'sprockets/webpackit'

Sprockets::Webpackit.pattern = /^*.js$/   # optional - override the default matcher
Sprockets::Webpackit.mode = 'production'  # optional - default is RACK_ENV or 'development'

map '/assets' do
   ...
end

to process a file the name must match the given pattern. The default is a suffix of .webpack.js , .webpack.coffee etc.

eg: in your application.js

//= require application.webpack.coffee

you could also set the pattern to eg /.*/to accept all javascript files.