Alternate Ways of Configuring Heroku for Webpack with Rails

Here’s an nice article from Arkency on configuring Rails with Webpack:

Creating custom Heroku buildpack for Webpack and Ruby on Rails integration

I’m going to compare this to how we configure react-webpack-rails-tutorial, live example at

The article does a fine job of explaining how to create a custom buildpack to solve the Rails + Webpack deployment problem.

At ShakaCode, we took a different approach:

  1. Some changes to our app
  2. Using the standard node buildpack

The article assumes the following about the application structure. Below each quoted bullet, I describe how our technique is different.

NOTE quoted sections like this are from the Arkency article.

package.json (one or two)

  • The Node.js package.json resides under app/assets within the Rails application root.

We create a top level package.json containing:

  "scripts": {
    "postinstall": "cd client && npm install",
    "test": "rspec && (cd client && npm run lint)"

The default node.js buildpack depends on the top level package.json.

Where We Put Our Client Code

  • Source files are stored under app/assets/source.

We use /app/client/app. This allows us to have the client app be isolated from the Rails app.

Manifest file for JavaScript

  • Webpack compiles the bundle into app/assets/javascripts directory and this bundle is required within application manifest (application.js)

We do the same thing in application.js:

//= require generated/vendor-bundle
//= require generated/app-bundle

devDependencies and the NODE_ENV

  • Webpack, Babel and loaders are installed as devDependencies so they are not installed if Node.js environment is set to production.
  • All JavaScript dependencies of the codebase are installed on the Node.js side as regular dependencies.
  • There is a npm script named build-production that creates the production-ready bundle (by production-ready I mean - deduped one)

We take a different approach:

  1. Add all build tools that heroku needs to dependencies. Since Webpack will strip out anything that is not referenced in the bundles, this is not problem.
  2. Configure our webpack.client.rails.config to depend on the NODE_ENV. Thus we have just one script for Rails.

This is how we determine if we’re doing a “devBuild”:

const devBuild = process.env.NODE_ENV !== 'production';