This page lists resources about Webpacker gem. It has supporting information to my talk State of the art of managing assets in new Rails world at Rubyconf Kenya 2019. It also has examples of code snippets which will help you migrate your legacy assets pipeline code to Webpacker.


Rails 5.1: Loving JavaScript, System Tests, Encrypted Secrets, and more

Webpacker 3.0: No separate process needed, less config generated

Make Webpacker the default JavaScript compiler for Rails 6

Rails 6.0.0 beta1: Action Mailbox, Action Text, Multiple DBs, Parallel Testing, Webpacker by default

My slides for the talk given at RubyConf Kenya


What problem webpack solves

Webpacker docs

Examples for legacy code

1) require_context

// app/javascript/packs/app.js
// import all files in a folder
require.context('../utils', true)

2) module-resolver

// Before

import "./coffee-maker"

// .babelrc 

  "plugins": [     
              ["module-resolver", { "root": ["./app/javascript"], 
                                    "alias": {} }

// After

import "coffee-maker"

3) Exporting webpack modules to global scope

output: {
  // Makes exports from entry packs available to global scope
  library: ['Packs', '[name]'],
  libraryTarget: 'var'

// app/javascript/packs/application.js

export { default as CoffeeMaker } from './coffee_maker'

// app/assets/javascripts/application.js


4) Exporting libraries to global scope

module: {
  rules: [
      test: require.resolve('jquery'),
      use: [{
        loader: 'expose-loader',
        options: '$',
      }, {
        loader: 'expose-loader',
        options: 'jQuery',

Good luck embracing modern JavsScript in your Rails app. Feel free to reach out to me on [email protected] if you have any questions about Webpacker.

If you want to know more such cool information about Ruby, Rails then subscribe to my newsletter.