my_engine
 +- app    # my engine stuff
 +- config # my engine stuff
 +- Gemfile
 +- lib    # my engine stuff
 +- public # my engine stuff
 +- spec
     +- controllers    # controller tests
     +- models         # model tests
     +- dummy          # a dummy application that is using the 'my_engine/Gemfile' 
     +- spec_helper.rb # the spec helper that boots the dummy app

在我加入Devise gem之前,我可以编写测试并运行它们

rake spec

现在我拥有Devise gem和这样的用户模型

class Manager::User < ActiveRecord::Base
    devise :database_authenticatable,:registerable,# ...
end

并且我的测试失败指向用户类和设计调用.

`method_missing': undefined method `devise'

所以现在我尝试调查错误,并找出如何使用设计和我的引擎一起启动虚拟应用程序.
规范助手看起来像这样

# my_engine/spec/spec_helper.rb#
ENV["RAILS_ENV"] ||= 'test'
require File.expand_path("../dummy/config/environment.rb",__FILE__) # boots the dummy app and fails
# more rspec stuff gies here

evnironment.rb

# my_engine/spec/dummy/config/environment.rb
# Load the rails application
require File.expand_path('../application',__FILE__)

# Initialize the rails application
Dummy::Application.initialize!

application.rb

# my_engine/spec/dummy/config/application.rb
require File.expand_path('../boot',__FILE__)
require 'rails/all'
Bundler.require(:default,Rails.env) if defined?(Bundler)
# Dummy::Application definition follows here (the common stuff)

boot.rb

# my_engine/spec/dummy/config/boot.rb
require 'rubygems'
# Loads the gemfile from 'my_engine/Gemfile'
gemfile = File.expand_path('../../../../Gemfile',__FILE__)

begin
  ENV['BUNDLE_GEMFILE'] = gemfile
  require 'bundler'
  Bundler.setup
rescue Bundler::GemNotFound => e
  STDERR.puts e.message
  STDERR.puts "Try running `bundle install`."
  exit!
end if File.exist?(gemfile)

宝石文件

# my_engine/Gemfile
source :gemcutter

gem 'rails','3.0.3'
gem 'rake'

gem 'devise','>=1.2.rc'
gem 'declarative_authorization','0.5.2'

group :test do
  gem "cucumber"
  gem "cucumber-rails"
  gem "database_cleaner"
  gem "capybara",">= 0.4.0"
  gem "capybara-envjs"
  gem "culerity"
  gem "webrat"
  gem "rspec-rails",">= 2.4.0"
  gem "jeweler"
end

我也试过这样要求我的引擎

gem "my_engine",:path => "./"

Gemfile和gem都被加载(Bundler.setup贯穿,Devise常量可用).
现在我创建了一个使用my_engine gem的外部应用程序.当我从我的引擎复制测试并运行它们时,它们都通过了.

有什么我想念的吗？也许有更好的方法来为引擎编写测试？