opal-rb-loader

Opal Webpack loader

Usage

This is a simple Webpack loader that shells out to Opal. It was built as an alternative to opal-webpack because I felt that transpiling files using their bootstrapped copy of the Opal compiler was too slow.

To use it, first install the package:

$ npm install --save opal-rb-loader

then configure the loader in your Webpack config:

module.exports = {
  // ...
  module: {
    rules: [
      { test: /\.rb$/, loader: 'opal-rb-loader' },
      // ...
    ]
  }
}

Make sure you have the opal binary somewhere in your PATH. See below for more details on installing Opal

Configuration

The only available option is includeOpal, which specifies whether or not the Opal compiler should automatically include the Opal core libraries when compiling your code. If you set this to false, you should add require 'opal' to the top of your Ruby files. This option defaults to true. To disable including Opal, specify it in the loader query:

{ test: /\.rb$/, loader: 'opal-rb-loader?includeOpal=false' },

Installing Opal

You can install Opal by running

$ gem install opal

If you'd like to use a bundled version of Opal, setup your Gemfile:

source 'https://rubygems.org'
 
gem 'opal'

and run bundle install. Then when you run webpack you can run it with bundle exec, and the loader will use the version of Opal that you installed via bundler.