所以......第一次向StackOverflow提问：
我将现有的Rails 4.2.5应用程序（使用Ruby 2.2.4）转换为Rails 5.1.3应用程序（使用Ruby 2.4.1），遵循Rails指南和RailsApps项目。
启动开发服务器会产生：
Taruns-iMac:Play_Ball tarunchattoraj$ rails s
=> Booting Puma
=> Rails 5.1.3 application starting in development on http://localhost:3000
=> Run `rails server -h` for more startup options
Puma starting in single mode...
* Version 3.9.1 (ruby 2.4.1-p111), codename: Private Caller
* Min threads: 5, max threads: 5
* Environment: development
* Listening on tcp://0.0.0.0:3000
Use Ctrl-C to stop
这就是我所期望的。
导航到localhost：3000会产生一个ActionController错误：
Started GET "/" for 127.0.0.1 at 2017-08-13 11:05:38 -0400
(0.2ms) SELECT "schema_migrations"."version" FROM "schema_migrations" ORDER BY "schema_migrations"."version" ASC
ActionController::RoutingError (Couldn't find Api::KeepScoresHelper, expected it to be defined in helpers/api/keep_scores_helper.rb):
app/controllers/application_controller.rb:1:in `<top (required)>'
app/controllers/welcome_controller.rb:1:in `<top (required)>'
我希望看到我的应用在网页上正常运行。
这question似乎很明显。我尝试了“触摸”所有帮助文件的解决方案，但无济于事。
当我从Rails 4.2.5转换为5.1.3时，我运行$ rails app:update并覆盖了大多数文件 - 那些我没有特定于我的应用程序的代码的文件，但我选择不覆盖配置/ routes.rb中。
config / routes.rb：
Rails.application.routes.draw do
resources :alerts
get 'games/decide_game_view' => 'games#decide_game_view', as: :decide_game_view
resources :games
resources :game_hitting_stats
resources :game_pitching_stats
resources :locations
resources :players
get 'welcome/index'
get 'welcome/about'
resources :users do
resources :players
end
resources :sessions, only: [:new, :create, :destroy]
resources :teams do
resources :notes
end
# namespace :api, defaults: {format: :http} do
namespace :api do
match '/texts', to: 'texts#preflight', via: [:options]
resources :texts, only: [:create]
match '/keepscore/teams', to: 'keep_scores#preflight', via: [:options]
get 'keepscore/teams' => 'keep_scores#get_teams', as: :get_teams
match '/keepscore/roster', to: 'keep_scores#preflight', via: [:options]
get 'keepscore/roster' => 'keep_scores#get_roster', as: :get_roster
match '/keepscore/post_game_stats', to: 'keep_scores#preflight', via: [:options]
post 'keepscore/post_game_stats' => 'keep_scores#post_game_stats', as: :post_game_stats
end
# The priority is based upon order of creation: first created -> highest priority.
# See how all your routes lay out with "rake routes".
# You can have the root of your site routed with "root"
# root 'welcome#index'
# Example of regular route:
# get 'products/:id' => 'catalog#view'
# Example of named route that can be invoked with purchase_url(id: product.id)
# get 'products/:id/purchase' => 'catalog#purchase', as: :purchase
# Example resource route (maps HTTP verbs to controller actions automatically):
# resources :products
# Example resource route with options:
# resources :products do
# member do
# get 'short'
# post 'toggle'
# end
#
# collection do
# get 'sold'
# end
# end
# Example resource route with sub-resources:
# resources :products do
# resources :comments, :sales
# resource :seller
# end
# Example resource route with more complex sub-resources:
# resources :products do
# resources :comments
# resources :sales do
# get 'recent', on: :collection
# end
# end
# Example resource route with concerns:
# concern :toggleable do
# post 'toggle'
# end
# resources :posts, concerns: :toggleable
# resources :photos, concerns: :toggleable
# Example resource route within a namespace:
# namespace :admin do
# # Directs /admin/products/* to Admin::ProductsController
# # (app/controllers/admin/products_controller.rb)
# resources :products
# end
root 'welcome#index'
end
ActionController似乎在告诉我它无法找到KeepScoresHelper模块并且它正在查找helpers / api / keep_scores_helper.rb。但该文件存在请参见Pic of App Controller and Helper Tree Structure。
helpers / api / keep_scores_helper.rb的内容：
module API::KeepScoresHelper
end
的Gemfile：
source 'https://rubygems.org'
ruby "2.4.1"
# Bundle edge Rails instead: gem 'rails', github: 'rails/rails'
gem 'rails', '5.1.3'
gem 'puma'
gem 'pundit'
gem 'bcrypt'
gem 'active_model_serializers', '~> 0.10.0'
# Use SCSS for stylesheets
gem 'sass-rails', '~> 5.0'
# Use Uglifier as compressor for JavaScript assets
gem 'uglifier', '>= 1.3.0'
# Use CoffeeScript for .coffee assets and views
gem 'coffee-rails', '~> 4.2.2'
# See https://github.com/rails/execjs#readme for more supported runtimes
# gem 'therubyracer', platforms: :ruby
# Use jquery as the JavaScript library
gem 'jquery-rails'
# Turbolinks makes following links in your web application faster. Read more: https://github.com/rails/turbolinks
gem 'turbolinks'
gem 'jquery-turbolinks'
gem 'bootstrap-sass'
gem 'figaro'
gem 'pry'
# Build JSON APIs with ease. Read more: https://github.com/rails/jbuilder
gem 'jbuilder', '~> 2.0'
# bundle exec rake doc:rails generates the API under doc/api.
gem 'sdoc', '~> 0.4.0', group: :doc
# Use ActiveModel has_secure_password
# gem 'bcrypt', '~> 3.1.7'
# Use Unicorn as the app server
# gem 'unicorn'
# Use Capistrano for deployment
# gem 'capistrano-rails', group: :development
group :production do
gem 'pg'
gem 'rails_12factor'
end
group :test do
gem 'pundit-matchers', '~>1.0.1'
end
group :development, :test do
# Call 'byebug' anywhere in the code to stop execution and get a debugger console
gem 'listen'
gem 'byebug'
gem 'web-console', '~> 3.5.1'
# Spring speeds up development by keeping your application running in the background. Read more: https://github.com/rails/spring
gem 'spring'
gem 'rspec-rails'
gem 'shoulda'
gem 'faker'
gem 'factory_girl_rails'
gem 'rails-controller-testing'
end
group :development do
# Access an IRB console on exception pages or by using <%= console %> in views
gem 'sqlite3'
end
当然，非常感谢任何帮助...
答案 0 :(得分：3)
希望帮助那些偶然发现这一点的人。
升级您在问题中提到的相同版本时，我遇到了同样的问题。我首先从4.2升级到5.0，然后从那里升级到5.1.3。
第一次升级工作正常但我开始收到相同的错误消息（例如uninitialized constant ActionController::RedirectBackError ...关于无法找到帮助程序，但这只发生在我跳到rails 5.1时。
我尝试了很多其他修复程序，如github issue中所述，因为它似乎是同样的错误，但没有任何效果，我的路径似乎都是正确的（路径或套管没有差异）。
我最终删除了所有帮助程序，并收到一条新错误，导致我在我的应用程序中找到导致问题的代码。
# app/controllers/application_controller.rb
# Catch exceptions if :back is not set throughout the app. This is a fallback redirect if request.referer is not set.
rescue_from ActionController::RedirectBackError do |exception|
redirect_to key_activities_ministries_activities_path, alert: exception.message
end
该代码导致路由错误：uninitialized constant ActionController::RedirectBackError。但是这个错误只出现在我删除所有助手的时候。 我删除了此代码，重新启用了帮助程序，然后重新启动了服务器，一切都按预期工作。
答案 1 :(得分：2)
在config / environments / development.rb中，设置：
config.action_controller.include_all_helpers = false
这会将Helpers返回到pre-Rails 5行为。对于Rails 5.1.3，每RoR API，“默认情况下，每个控制器都包含所有帮助程序。” Pre Rails 5，控制器将包括与其名称匹配的帮助程序。进行上述指定的设置将返回Pre-Rails 5行为。