[Rails][CodeReading] Rails::Initializer (29) (30) check_gem_dependencies

Initializer.process で29番目に呼ばれる check_gem_dependencies メソッド。

   def check_gem_dependencies
     unloaded_gems = @configuration.gems.reject { |g| g.loaded? }
     if unloaded_gems.size > 0
       @gems_dependencies_loaded = false
       # don't print if the gems rake tasks are being run
       unless $gems_rake_task
         abort <<-end_error
Missing these required gems:
 #{unloaded_gems.map { |gem| "#{gem.name}  #{gem.requirement}" } * "\n  "}

You're running:
 ruby #{Gem.ruby_version} at #{Gem.ruby}
 rubygems #{Gem::RubyGemsVersion} at #{Gem.path * ', '}

Run `rake gems:install` to install the missing gems.
         end_error
       end
     else
       @gems_dependencies_loaded = true
     end
   end

# initializer.rb
     check_gem_dependencies

     # bail out if gems are missing - note that check_gem_dependencies will have
     # already called abort() unless $gems_rake_task is set
     return unless gems_dependencies_loaded

ロードされていないgemが残っていて、かつgems rake tasks中でなければabortしています。


[Rails][CodeReading] Railsの初期化コードを読む (イントロ＆目次)