RSpec 2 library for specifying and testing generators

This project contains RSpec 2 matchers, helpers and various utilities to assist in writing Rails 3 generator specs.

Rails 3 has a Rails::Generators::TestCase class for use with Test-Unit, to help test generators. This TestCase contains specific custom assertion methods that can be used to assert generator behavior. To create an RSpec 2 equivalent, I wrapped Rails::Generators::TestCase for use with RSpec 2 and created some RSpec 2 matchers that mimic the assertion methods of the Test-Unit TestCase. I have also a bunch of "extra goodies" to the mix. The new intuitive DSL RSpec DSL for specifying/testing generators should make it very easy and intuitive to test your Rails 3 generators with RSpec 2 :)

Please advice if you find any issues or have suggestions for improvements. The code is not as pretty as it could be, so feel free to refactor and improve this gem to your hearts desire!

Install

gem install generator-spec

Install from code

The gem is a jewel based on jeweler. To install the gem from the code, simply use the jeweler rake task:

rake install

Usage

The following demonstrates usage of this gem. There are many more options and DSL convenience methods.

Configuration

First setup the spec_helper.rb. Here is an example configuration.

# spec/spec_helper.rb
  
require 'rspec'
require 'generators_spec'

# configure it like this to use default settings
RSpec::Generator.configure do |config|
  config.debug = false
  config.remove_temp_dir = true
  config.default_rails_root(__FILE__)
end

# or customize the location of the temporary Rails 3 app dir used
RSpec::Generator.configure do |config|
  config.debug = false
  config.remove_temp_dir = true
  config.rails_root = '~/my/rails/folder'
end

Specs for generators

I recommend having a separate spec for each generator called a 'generator spec'. You can use the special require_generator statement to ensure that one or more generators are loaded and made available for the spec.

require_generator :canable

This will load the generator : generators/canabale_generator.rb

If the generator is in a namespace, use a nested approach like this:

require_generators :canable => ['model', 'user']

This will load the generators: generators/canable/model_generator.rb and generators/canable/user_generator.rb

You can also load generators from multiple namespaces and mix and match like this

require_generators [:canable => ['model', 'user'], :other => :side, :simple]

Auto-require all generators

You can also require all generators or all within a specific namespace like this:

require_generators :all require_generators :canable => :all

Using a shared generator loader file

If you have multiple generators in a shared namespace, the following alternative approach can be used. Create a file that loads all the generators you are specifying in this folder, fx all generators in a specific namespace. Then include this 'generator load file' in each spec.

This uses the 'require_all' gem functionality

Example usage: require generators

# spec/generators/canable.rb
require_generators :canable => ['model', 'user']

# spec/generators/canable/model_generator_spec.rb
...
# load generators to spec
require 'generators/canable'

describe 'model_generator' do
  ...   
end

# spec/generators/canable/user_generator_spec.rb
...
# load generators to spec
require 'generators/canable'

describe 'user_generator' do
  ...   
end

Example: full generator spec

# spec/generators/model_generator_spec.rb  

require File.expand_path(File.dirname(__FILE__) + '/../spec_helper')

# list of generators to spec are loaded
require 'generators/canable'

describe 'model_generator' do
  # include Rails model helpers for ActiveRecord
  # available: MongoMapper, Mongoid and DataMapper
  
  include RSpec::Rails::Orm::ActiveRecord
  
  before :each do              
    # define generator to test
    setup_generator 'model_generator' do
      tests Canable::Generators::ModelGenerator
    end    
    # ensure clean state before run
    remove_model :account
  end

  after :each do              
    # ensure clean state after each run  
    remove_model :account
  end
    
  it "should not work without an existing Account model file" do            
    with_generator do |g|   
      g.run_generator :account.args
      g.should_not generate_file :account, :model
    end
  end

  it "should decorate an existing Account model file with 'include Canable:Ables'" do            
    with_generator do |g|  
      create_model :account     
      g.run_generator 'account'.args
      g.should generate_model :account do |content|
        content.should have_class :account do |klass|
          klass.should include_module 'Canable::Ables'
        end
      end
    end
  end
end

Note on Patches/Pull Requests

Fork the project.
Make your feature addition or bug fix.
Add tests for it. This is important so I don't break it in a future version unintentionally.
Commit, do not mess with rakefile, version, or history. (if you want to have your own version, that is fine but bump version in a commit by itself I can ignore when I pull)
Send me a pull request. Bonus points for topic branches.