RequireJS + Rails + Jasmine

This repository is a tutorial and straw-man design proposal for integrating Jasmine test support into a Rails app using RequireJS via the requirejs-rails gem. My ultimate goal is to see all of this wrapped up so that it's as easy as adding a gem to your app's Gemfile.

Goals

it should play nicely with the Asset Pipeline

Rails' Asset Pipeline provides useful conventions, plugins, workflow and tools. As much as possible, I'd like to preserve that while bringing the benefits of RequireJS and Jasmine into play.

it should be DRY

A suite of AMD source code in a Rails app makes its dependencies explicit via require() and define() calls. The Jasmine configuration should not make the developer reiterate this knowledge.

Other Approaches

guard

One approach by Michael Kessler uses guard to transpile and assemble the test suite from sources and specs. This is handy for general Ruby apps without Sprockets. For a Rails app, it fails to be DRY and doesn't respect the configuration and processing built into the Asset Pipeline.

Jasmine helpers

Scott Burch's jasmine-require helper is another integration approach. I honestly never did get it configured and working with requirejs-rails, but that's probably a (lack of) documentation issue. Setup aside, Scott's requireStubs() call is a nice idea worth keeping in mind.

My personal bias is that I would prefer a "native-AMD" module style rather than a Jasmine helper.

Step-by-step guide

This section explains the changes made to enable Jasmine support with requirejs-rails as described in the Introduction.

Based on the above discussion, here are some guidelines this template adheres to:

• Asset path compatibility: Specs should reference source files using the same path structure as the source files themselves use.
• Specs live in spec/javascripts/spec. Like any asset, they can be in any format that transpiles to JavaScript, such as CoffeeScript.
• Helpers live in spec/javascripts/helpers as usual. They are not currently processed through Sprockets, so CoffeeScript, etc. is not supported.

Update Gemfile

Add these lines to your Gemfile, then run bundle install:

gem 'requirejs-rails', '~> 0.8.0'

group :development, :test do
  gem 'jasmine', :git => 'git://github.com/pivotal/jasmine-gem.git'
end

Run the jasmine generator

rake g jasmine:install

Update development asset paths

Add this line to config/environments/development.rb:

config.assets.paths << Rails.root.join("spec", "javascripts")

Add files from this repository

You'll need to add these files, in these relative locations, to your Rails app:

spec/javascripts/support/jasmine_config.rb
spec/javascripts/support/run.html.erb
spec/javascripts/support/jasmine.yml

Add specs

Create your specs in spec/javascripts/spec. Check out the example spec file in that directory. To run it, start the jasmine server via the usual rake jasmine and navigate to http://localhost:8888/.

A spec in CoffeeScript would look like this:

define (require) ->
  PlaylistModel = require('models/playlist_model')

  describe 'existence', ->
    it 'should be defined', ->
      expect(PlaylistModel).toBeDefined()