如何修复Rails i18n中的“No Route Matches”路由匹配错误

问题分析 #

从错误信息能看出，路由生成时把@user对象错误赋值给了:locale参数，导致缺少必填的:id参数。核心原因有两点：

• 测试环境未继承ApplicationController中设置的default_url_options，路由助手无法自动携带locale参数
• 路由规则里的locale正则表达式存在空格，导致匹配异常

修复步骤 #

1. 修正路由规则中的正则表达式 #

打开config/routes.rb，去掉locale正则里的空格，并删除冗余路由：

Rails.application.routes.draw do
  # 修正正则表达式：移除空格，确保locale匹配正确
  scope "(:locale)", locale: /en|ja/ do
    root 'static_pages#home'

    # 删除这条冗余路由——scope已经处理了locale前缀，避免路由冲突
    # get     '/:locale' => 'static_pages#home'
    
    # 其余路由保留不变
    get     '/help',        to: 'static_pages#help'
    get     '/about',       to: 'static_pages#about'
    get     '/contact',     to: 'static_pages#contact'
    get     '/search',      to: 'movies#search'
    get     '/show',        to: 'movies#show'
    get     '/signup',      to: 'users#new'
    post    '/signup',      to: 'users#create'
    post    '/guest_login', to: 'guest_sessions#create'
    get     '/login',       to: 'sessions#new'
    post    '/login',       to: 'sessions#create'
    delete  '/logout',      to: 'sessions#destroy'
    resources :users do
      member do
        get :following, :followers
      end
    end
    resources :movies
    resources :account_activations, only: [:edit]
    resources :resend_activations,  only: [:new, :create]
    resources :password_resets,     only: [:new, :create, :edit, :update]
    resources :comments do
      resource :comments,           only: [:create, :new, :edit, :update, :destroy]
      resource :favorites,          only: [:create, :destroy]
    end
    resources :relationships,       only: [:create, :destroy]
  end
end

2. 让测试继承默认URL参数设置 #

打开test/test_helper.rb，在ActionDispatch::IntegrationTest类中添加default_url_options方法，确保测试中的路由助手自动携带locale参数：

class ActionDispatch::IntegrationTest
  def default_url_options
    { locale: I18n.locale }
  end
end

3. （可选）单个测试方法临时修复 #

如果不想修改全局测试配置，也可以在报错的测试方法中明确传递locale参数：

test "should redirect edit when not logged in" do
  # 明确指定locale参数，避免路由助手参数错乱
  get edit_user_path(@user, locale: I18n.default_locale)
  assert_not flash.empty?
  assert_redirected_to login_url
end

验证修复 #

运行对应测试命令确认错误消失：

rails test test/controllers/users_controller_test.rb:21

内容的提问来源于stack exchange，提问作者jack20xx