RSpec on Railsで、controllerで使うライブラリのテストをする (環境 : ruby 1.9.2, rails : 3.0.9, rspec-rails : 2.1.12)

application.rb

require File.expand_path('../boot', __FILE__)

require 'rails/all'

# If you have a Gemfile, require the gems listed there, including any gems
# you've limited to :test, :development, or :production.
Bundler.require(:default, Rails.env) if defined?(Bundler)

module AppLibTest
  class Application < Rails::Application
    # Settings in config/environments/* take precedence over those specified here.
    # Application configuration should go into files in config/initializers
    # -- all .rb files in that directory are automatically loaded.

    # Custom directories with classes and modules you want to be autoloadable.
    # config.autoload_paths += %W(#{config.root}/extras)
    # lib以下をautoloadする
    config.autoload_paths += Dir["#{config.root}/lib/**/"]

    # Only load the plugins named here, in the order given (default is alphabetical).
    # :all can be used as a placeholder for all plugins not explicitly named.
    # config.plugins = [ :exception_notification, :ssl_requirement, :all ]

    # Activate observers that should always be running.
    # config.active_record.observers = :cacher, :garbage_collector, :forum_observer

    # Set Time.zone default to the specified zone and make Active Record auto-convert to this zone.
    # Run "rake -D time" for a list of tasks for finding time zone names. Default is UTC.
    # config.time_zone = 'Central Time (US & Canada)'

    # The default locale is :en and all translations from config/locales/*.rb,yml are auto loaded.
    # config.i18n.load_path += Dir[Rails.root.join('my', 'locales', '*.{rb,yml}').to_s]
    # config.i18n.default_locale = :de

    # JavaScript files you want as :defaults (application.js is always included).
    # config.action_view.javascript_expansions[:defaults] = %w(jquery rails)

    # Configure the default encoding used in templates for Ruby 1.9.
    config.encoding = "utf-8"

    # Configure sensitive parameters which will be filtered from the log file.
    config.filter_parameters += [:password]
  end
end

test_lib.rb

# -*- encoding: utf-8 -*-
module TestLib
  # includeされたら、before_filterを追加する
  def self.included(klass)
    klass.class_eval do
      before_filter :add_unit
    end
  end
  # "円"を追加する
  def add_unit
    params['price'] = "#{params['price']}円"
  end
end

test_lib_spec.rb

# -*- encoding: utf-8 -*-
require File.dirname(__FILE__) + '/../spec_helper'

# テスト用のコントローラ
class TestLibController < ApplicationController
  include TestLib
  def index
    response.content_type = 'text/html'
    render :text => params['price']
  end
end

# :type => :controller でcontrollerのspec_helperを使えるようにする
# * controllerディレクトリのテストの場合は勝手にやってくれる
describe TestLibController, :type => :controller do
  before :all do
    # テスト用のroutesを追加
    AppLibTest::Application.routes.draw do
      match 'index', :to => 'test_lib#index'
    end
  end

  # routesの初期化
  after(:all){ Rails.application.reload_routes! }

  subject do
    get :index, :price => '100'
    response
  end
  it{ subject.should be_success }
  its(:body){ '100円' }
end