Rails 项目：NoMethodError：字符串的未定义方法“标识符”

Question

我最近继承了一个 Rails + Spine.JS 项目。尽管它的主题不是非常神秘的东西（面向营销：人们制作自己的邮件列表，在发送之前准备内容，实际发送等等），但是它的实现是特定的并且依赖于多个 Rails 覆盖（就像下面问题 #2 中指定的那样）。

我有两个问题需要帮助。

问题一：

直截了当：在 Spine.JS 应用程序（前端）中，我们有一个发票预览操作，它应该（并且确实）打开一个新选项卡来执行此操作。在我真正做到之前，一切看起来都很正常。没有太多毫无意义的解释，这就是发生的事情：

Started GET "/me/invoices/22/preview?oauth_token=XE03DFCGyCDYjdu8oWuU9zrN56Z6Wr7eZDuIjCbT&origin=http://localhost:9294" for 94.26.14.131 at 2013-12-08 00:55:27 +0200
  Oauth2Token Load (0.3ms)  SELECT `oauth_tokens`.* FROM `oauth_tokens` WHERE `oauth_tokens`.`type` IN ('Oauth2Token') AND (invalidated_at IS NULL AND authorized_at IS NOT NULL and token = 'XE03DFCGyCDYjdu8oWuU9zrN56Z6Wr7eZDuIjCbT') LIMIT 1
Processing by InvoicesController#preview as HTML
  Parameters: {"oauth_token"=>"XE03DFCGyCDYjdu8oWuU9zrN56Z6Wr7eZDuIjCbT", "origin"=>"http://localhost:9294", "id"=>"22"}
  User Load (0.4ms)  SELECT `users`.* FROM `users` WHERE `users`.`id` = 270932 LIMIT 1
  Invoice Load (0.2ms)  SELECT `receipts`.* FROM `receipts` WHERE `receipts`.`type` IN ('Invoice') AND `receipts`.`id` = 22 LIMIT 1
Completed 500 Internal Server Error in 8.3ms

NoMethodError (undefined method `identifier' for "preview":String):
  newrelic_rpm (3.6.9.171) lib/new_relic/agent/instrumentation/rails3/action_controller.rb:157:in     `render_with_newrelic'
  actionpack (3.2.16) lib/action_view/renderer/renderer.rb:36:in `render_template'
  actionpack (3.2.16) lib/action_view/renderer/renderer.rb:17:in `render'
  actionpack (3.2.16) lib/abstract_controller/rendering.rb:110:in `_render_template'
  actionpack (3.2.16) lib/action_controller/metal/streaming.rb:225:in `_render_template'
  actionpack (3.2.16) lib/abstract_controller/rendering.rb:103:in `render_to_body'
  actionpack (3.2.16) lib/action_controller/metal/renderers.rb:28:in `render_to_body'
  actionpack (3.2.16) lib/action_controller/metal/compatibility.rb:50:in `render_to_body'
  actionpack (3.2.16) lib/abstract_controller/rendering.rb:88:in `render'
  actionpack (3.2.16) lib/action_controller/metal/rendering.rb:16:in `render'
  actionpack (3.2.16) lib/action_controller/metal/instrumentation.rb:40:in `block (2 levels) in render'
  activesupport (3.2.16) lib/active_support/core_ext/benchmark.rb:5:in `block in ms'
  /usr/local/rvm/rubies/ruby-2.0.0-p353/lib/ruby/2.0.0/benchmark.rb:296:in `realtime'

...等等。如您所见，单词preview 是控制器操作的名称。

删除 NewRelic 没有帮助。然后错误被替换为：

NoMethodError (undefined method `formats' for "preview":String):

顺便说一句，Ruby 是 2.0.0-p353，Rails 是 3.2.16。 Rails 项目有一些自定义项，例如大多数操作的 OAuth 参数——因为 Rails 应用程序主要是 Node.JS 项目的服务器存储单元。

查看 API 文档（如这里：http://www.rubydoc.info/docs/rails/3.1.1/ActionView/Template）给我的印象是 determine_template Rails 方法（以及第二种情况下未指定的方法，没有 newrelic_rpm）不会返回 ActionView::Template但是String。知道为什么会这样吗？

问题二：

在大多数情况下，调用 rake cucumber 实际上会产生这种情况：

stack level too deep (SystemStackError)

之前的开发者确实有这个作为ActiveRecord::Base的扩展：

module ActiveRecord
  class Base
    include Documentable
    ...
    def self.has_url
      include Rails.application.routes.url_helpers

      self.default_url_options = Rails.application.default_url_options

      define_method :url do
        send "#{self.class.to_s.underscore}_url", self
      end
    end
  end
end

当然，这可能是原因。我已经尝试通过ActiveRecord::Concern 方法替换用于扩展 ActiveRecord 的（相当过时的）方法，遗憾的是这没有任何区别。我已经对这个项目进行了相当广泛的 grep，这是其中唯一一个实际包含 Rails 模块的地方，所以现在应该是该错误的唯一候选者，不是吗？

对于这两个问题，我完全不知所措。我在 Rails（大约 15 个项目）方面获得了一些经验，并且从未遇到过这样的一年级问题。

感谢您的关注。任何想法都会受到赞赏，即使我已经尝试过了。

更新 #1：

根据要求，将before_filters 粘贴到ApplicationController。

  def remove_oauth_params
    params.reject! {|k,_| %w[oauth_token bearer_token access_token].include? k}
  end

  def save_action
    @current_action = params[:action]
  end

  def set_access_header
    if request.path == "/users/sign_out"
      headers["Access-Control-Allow-Credentials"] = "true"
      headers["Access-Control-Allow-Headers"] = %w{Origin Accept Content-Type X-Requested-With X-CSRF-Token X-File-Name X-File-Size Cache-Control}.join(",")
      headers["Access-Control-Allow-Methods"] = "DELETE"
      headers["Access-Control-Allow-Origin"] = "http://#{Settings.app_domain}"
    else
      headers["Access-Control-Allow-Origin"]  = "*"
      headers["Access-Control-Allow-Methods"] = %w{GET POST PUT DELETE PATCH}.join(",")
      headers["Access-Control-Allow-Headers"] = %w{Origin Accept Content-Type X-Requested-With X-CSRF-Token X-File-Name X-File-Size Cache-Control}.join(",")
    end
    head(:ok) if request.request_method == "OPTIONS"
  end

  def set_limit_and_offset
    @limit = params.delete(:limit).to_i
    @limit = default_limit unless (1..default_limit).include?(@limit)
    @offset = params.delete(:offset).to_i
    @offset = 0 unless @offset > 0
  end

至于InvoiceController，该死的基本：

class InvoicesController < ApplicationController
  oauthenticate :interactive => false

  layout "invoice"

  def preview
    @i = Invoice.find(params[:id])
    @origin = params[:origin]
  end
end

更新 #2：

$ rake cucumber --trace
** Invoke cucumber (first_time)
** Invoke cucumber:ok (first_time)
** Invoke db:test:prepare (first_time)
** Invoke db:abort_if_pending_migrations (first_time)
** Invoke environment (first_time)
** Execute environment
[deprecated] I18n.enforce_available_locales will default to true in the future. If you really want to skip validation of your locale you can set I18n.enforce_available_locales = false to avoid this message.
** Invoke db:load_config (first_time)
** Execute db:load_config
** Execute db:abort_if_pending_migrations
** Execute db:test:prepare
** Invoke db:test:load (first_time)
** Invoke db:test:purge (first_time)
** Invoke environment 
** Invoke db:load_config 
** Execute db:test:purge
** Invoke environment 
** Execute db:test:load
** Invoke db:test:load_schema (first_time)
** Invoke db:test:purge 
** Execute db:test:load_schema
** Invoke db:schema:load (first_time)
** Invoke environment 
** Invoke db:load_config 
** Execute db:schema:load
** Invoke db:seed (first_time)
** Execute db:seed
** Invoke db:abort_if_pending_migrations 
building users for ce and ce-int brands
building example CE app owner
building CE beta app
** Execute cucumber:ok
/usr/local/rvm/rubies/ruby-2.0.0-p353/bin/ruby -S bundle exec cucumber  --profile default
Using the default profile...
[deprecated] I18n.enforce_available_locales will default to true in the future. If you really want to skip validation of your locale you can set I18n.enforce_available_locales = false to avoid this message.
Feature: Creation of robinson entries
  Create a robinson entry to prevent recipients from being mailed

  Background:                                                          # features/blocked_address/blocked_address_creation.feature:4
    Given there is the example customer with id 200                    # features/step_definitions/data_steps.rb:41
      stack level too deep (SystemStackError)
      features/blocked_address/blocked_address_creation.feature:5:in `Given there is the example customer with id 200'

Answer 1

编辑：请参阅dimitkos comment 了解解决方案。

恐怕我没有简单的答案，只有两个调试建议：

对于问题 1：

• 包括 Ruby 调试器
• 在控制台中，调用app.get "/me/invoices/22/preview?oauth_token=XE03DFCGyCDYjdu8oWuU9zrN56Z6Wr7eZDuIjCbT&origin=http://localhost:9294"
• 在堆栈中查找字符串的来源

至于2：你用git做源码控制吗？

如果是，那么现在是试用git bisect 的绝佳时机。你会找到一个较旧的提交，rake cucumber 仍在工作，而 git 可以帮助你找到破坏它的提交，只需几个步骤。更多内容：Debugging with Git - Binary search