rails 从 1.8.7 升级到 1.9.2 引入语法错误答案

【问题标题】：rails upgrade from 1.8.7 to 1.9.2 introduces syntax errorrails 从 1.8.7 升级到 1.9.2 引入语法错误
【发布时间】：2011-12-22 06:16:29
【问题描述】：

目前使用 ruby-1.8.7-p302 [ i386 ]

转向 ruby ruby-1.9.2-p0 [ i386 ]

运行轨道 3.0.0

升级后出现以下错误：

# RAILS_ENV=production rails s
=> Booting WEBrick
=> Rails 3.0.0 application starting in production on http://0.0.0.0:3000
=> Call with -d to detach
=> Ctrl-C to shutdown server
Exiting
/usr/local/rvm/gems/ruby-1.9.2-p0/gems/actionpack-3.0.0/lib/abstract_controller/helpers.rb:53:in `class_eval': /usr/local/rvm/gems/ruby-1.9.2-p0/gems/actionpack-3.0.0/lib/abstract_controller/helpers.rb:54: syntax error, unexpected tLBRACE (SyntaxError)
        def {:only=>:after_sign_in_path_for}(*args, &blk)
             ^
/usr/local/rvm/gems/ruby-1.9.2-p0/gems/actionpack-3.0.0/lib/abstract_controller/helpers.rb:54: syntax error, unexpected '(', expecting $end
        def {:only=>:after_sign_in_path_for}(*args, &blk)
                                             ^
from /usr/local/rvm/gems/ruby-1.9.2-p0/gems/actionpack-3.0.0/lib/abstract_controller/helpers.rb:53:in `block in helper_method'
from /usr/local/rvm/gems/ruby-1.9.2-p0/gems/actionpack-3.0.0/lib/abstract_controller/helpers.rb:52:in `each'
from /usr/local/rvm/gems/ruby-1.9.2-p0/gems/actionpack-3.0.0/lib/abstract_controller/helpers.rb:52:in `helper_method'
from /var/www/html/matcha/app/controllers/application_controller.rb:8:in `<class:ApplicationController>'
from /var/www/html/matcha/app/controllers/application_controller.rb:1:in `<top (required)>'
from /usr/local/rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.0/lib/active_support/dependencies.rb:239:in `require'
from /usr/local/rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.0/lib/active_support/dependencies.rb:239:in `block in require'
from /usr/local/rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.0/lib/active_support/dependencies.rb:227:in `load_dependency'
from /usr/local/rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.0/lib/active_support/dependencies.rb:239:in `require'
from /usr/local/rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.0/lib/active_support/dependencies.rb:346:in `require_or_load'
from /usr/local/rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.0/lib/active_support/dependencies.rb:491:in `load_missing_constant'
from /usr/local/rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.0/lib/active_support/dependencies.rb:183:in `block in const_missing'
from /usr/local/rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.0/lib/active_support/dependencies.rb:181:in `each'
from /usr/local/rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.0/lib/active_support/dependencies.rb:181:in `const_missing'
from /usr/local/rvm/gems/ruby-1.9.2-p0/gems/aws-s3-0.6.2/lib/aws/s3/extensions.rb:206:in `const_missing_from_s3_library'
from /usr/local/rvm/gems/ruby-1.9.2-p0/gems/devise-1.5.3/app/controllers/devise/confirmations_controller.rb:1:in `<top (required)>'
from /usr/local/rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.0/lib/active_support/dependencies.rb:239:in `require'
from /usr/local/rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.0/lib/active_support/dependencies.rb:239:in `block in require'
from /usr/local/rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.0/lib/active_support/dependencies.rb:227:in `load_dependency'
from /usr/local/rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.0/lib/active_support/dependencies.rb:239:in `require'
from /usr/local/rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.0/lib/active_support/dependencies.rb:346:in `require_or_load'
from /usr/local/rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.0/lib/active_support/dependencies.rb:300:in `depend_on'
from /usr/local/rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.0/lib/active_support/dependencies.rb:216:in `require_dependency'
from /usr/local/rvm/gems/ruby-1.9.2-p0/gems/railties-3.0.0/lib/rails/engine.rb:138:in `block (2 levels) in eager_load!'
from /usr/local/rvm/gems/ruby-1.9.2-p0/gems/railties-3.0.0/lib/rails/engine.rb:137:in `each'
from /usr/local/rvm/gems/ruby-1.9.2-p0/gems/railties-3.0.0/lib/rails/engine.rb:137:in `block in eager_load!'
from /usr/local/rvm/gems/ruby-1.9.2-p0/gems/railties-3.0.0/lib/rails/engine.rb:135:in `each'
from /usr/local/rvm/gems/ruby-1.9.2-p0/gems/railties-3.0.0/lib/rails/engine.rb:135:in `eager_load!'
from /usr/local/rvm/gems/ruby-1.9.2-p0/gems/railties-3.0.0/lib/rails/application/railties.rb:11:in `each'
from /usr/local/rvm/gems/ruby-1.9.2-p0/gems/railties-3.0.0/lib/rails/application/railties.rb:11:in `all'
from /usr/local/rvm/gems/ruby-1.9.2-p0/gems/railties-3.0.0/lib/rails/application.rb:107:in `eager_load!'
from /usr/local/rvm/gems/ruby-1.9.2-p0/gems/railties-3.0.0/lib/rails/application/finisher.rb:41:in `block in <module:Finisher>'
from /usr/local/rvm/gems/ruby-1.9.2-p0/gems/railties-3.0.0/lib/rails/initializable.rb:25:in `instance_exec'
from /usr/local/rvm/gems/ruby-1.9.2-p0/gems/railties-3.0.0/lib/rails/initializable.rb:25:in `run'
from /usr/local/rvm/gems/ruby-1.9.2-p0/gems/railties-3.0.0/lib/rails/initializable.rb:50:in `block in run_initializers'
from /usr/local/rvm/gems/ruby-1.9.2-p0/gems/railties-3.0.0/lib/rails/initializable.rb:49:in `each'
from /usr/local/rvm/gems/ruby-1.9.2-p0/gems/railties-3.0.0/lib/rails/initializable.rb:49:in `run_initializers'
from /usr/local/rvm/gems/ruby-1.9.2-p0/gems/railties-3.0.0/lib/rails/application.rb:134:in `initialize!'
from /usr/local/rvm/gems/ruby-1.9.2-p0/gems/railties-3.0.0/lib/rails/application.rb:77:in `method_missing'
from /var/www/html/matcha/config/environment.rb:5:in `<top (required)>'
from /usr/local/rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.0/lib/active_support/dependencies.rb:239:in `require'
from /usr/local/rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.0/lib/active_support/dependencies.rb:239:in `block in require'
from /usr/local/rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.0/lib/active_support/dependencies.rb:225:in `block in load_dependency'
from /usr/local/rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.0/lib/active_support/dependencies.rb:591:in `new_constants_in'
from /usr/local/rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.0/lib/active_support/dependencies.rb:225:in `load_dependency'
from /usr/local/rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.0/lib/active_support/dependencies.rb:239:in `require'
from /var/www/html/matcha/config.ru:3:in `block in <main>'
from /usr/local/rvm/gems/ruby-1.9.2-p0/gems/rack-1.2.4/lib/rack/builder.rb:46:in `instance_eval'
from /usr/local/rvm/gems/ruby-1.9.2-p0/gems/rack-1.2.4/lib/rack/builder.rb:46:in `initialize'
from /var/www/html/matcha/config.ru:1:in `new'
from /var/www/html/matcha/config.ru:1:in `<main>'
from /usr/local/rvm/gems/ruby-1.9.2-p0/gems/rack-1.2.4/lib/rack/builder.rb:35:in `eval'
from /usr/local/rvm/gems/ruby-1.9.2-p0/gems/rack-1.2.4/lib/rack/builder.rb:35:in `parse_file'
from /usr/local/rvm/gems/ruby-1.9.2-p0/gems/rack-1.2.4/lib/rack/server.rb:162:in `app'
from /usr/local/rvm/gems/ruby-1.9.2-p0/gems/rack-1.2.4/lib/rack/server.rb:253:in `wrapped_app'
from /usr/local/rvm/gems/ruby-1.9.2-p0/gems/rack-1.2.4/lib/rack/server.rb:204:in `start'
from /usr/local/rvm/gems/ruby-1.9.2-p0/gems/railties-3.0.0/lib/rails/commands/server.rb:65:in `start'
from /usr/local/rvm/gems/ruby-1.9.2-p0/gems/railties-3.0.0/lib/rails/commands.rb:30:in `block in <top (required)>'
from /usr/local/rvm/gems/ruby-1.9.2-p0/gems/railties-3.0.0/lib/rails/commands.rb:27:in `tap'
from /usr/local/rvm/gems/ruby-1.9.2-p0/gems/railties-3.0.0/lib/rails/commands.rb:27:in `<top (required)>'
from script/rails:6:in `require'
from script/rails:6:in `<main>'

相关的application_controller代码：

class ApplicationController < ActionController::Base
  include Facebooker2::Rails::Controller
  helper :all # include all helpers, all the time
  protect_from_forgery
  layout :layout_by_resource
  before_filter :set_cache_buster
  before_filter :current_facebook_user, :only => :after_sign_in_path_for
  helper_method :current_facebook_client, :only => :after_sign_in_path_for
  ...
end

它在“helper_method :current_facebook_client, :only => :after_sign_in_path_for”上大吃一惊，但在我的一生中，我看不出语法有什么问题（尤其是因为它在 1.8.7 中有效。

【问题讨论】：

尝试升级到最新的 1.9.2 或 1.9.3
为什么 helper_method “只”存在于 after_sign_in_path_for... 它是一种方法。你不应该有 :only => :after_sign_in_path_for

标签： ruby-on-rails ruby ruby-1.9.2

【解决方案1】：

对 helper_method 的方法调用是错误的，helper_method(*meths) 采用可变数量的符号表示助手名称，它确实不采用 opts 哈希 helper_method(*meths, opts = {})

# from http://api.rubyonrails.org/

helper_method(*meths)
# Declare a controller method as a helper. For example, the 
# following makes the current_user controller method available to the view:

class ApplicationController < ActionController::Base
  helper_method :current_user, :logged_in?

  def current_user
    @current_user ||= User.find_by_id(session[:user])
  end

   def logged_in?
     current_user != nil
   end
end

【讨论】：

顺便说一句，如果你要升级 ruby，我建议使用 ruby 1.9.2-p290 而不是 -p0 有很多修复。
如果他正在升级，那么他还不如升级到 1.9.3-p0，据说在 Rails 启动时间方面有很多加速。或者同时出现了那个版本和 Rails 的任何新问题？
我还没有尝试过 1.9.3，所以我不能保证它，但是，是的，听起来很合理。
尝试将我的 1.9.2-p290 升级到 ruby 1.9.3（对于 rails 3.0.X 项目）并在堆栈级别上运行测试太深。另一个项目在安装 RedCloth 时死了，所以我在 1.9.3 上还没有运气。 YMMV。