ルーティングエラーが消えないのはなぜ？

Question

Railsチュートリアルの11.2.2のところで、アカウント有効化メールのプレビューが表示されず躓いています。
どなたかわかるかた、ご教示ください！

エラー内容は以下の通りです。

---

そしてここでいじったのが
・config/environments/development.rbファイル

Rails.application.configure do
  # Settings specified here will take precedence over those in config/application.rb.
  # In the development environment your application's code is reloaded on
  # every request. This slows down response time but is perfect for development
  # since you don't have to restart the web server when you make code changes.
  config.cache_classes = false

  # Do not eager load code on boot.
  config.eager_load = false

  # Show full error reports.
  config.consider_all_requests_local = true

  # Enable/disable caching. By default caching is disabled.
  if Rails.root.join('tmp/caching-dev.txt').exist?
    config.action_controller.perform_caching = true

    config.cache_store = :memory_store
    config.public_file_server.headers = {
      'Cache-Control' => "public, max-age=#{2.days.seconds.to_i}"
    }
  else
    config.action_controller.perform_caching = false

    config.cache_store = :null_store
  end
  
  config.action_mailer.raise_delivery_errors = true
  config.action_mailer.delivery_method = :test
  host = 'rails-tutorial-mhartl.c9users.io'     # クラウドIDE
config.action_mailer.default_url_options = { host: host, protocol: 'https' }

  # Don't care if the mailer can't send.
  config.action_mailer.raise_delivery_errors = false

  config.action_mailer.perform_caching = false

  # Print deprecation notices to the Rails logger.
  config.active_support.deprecation = :log

  # Raise an error on page load if there are pending migrations.
  config.active_record.migration_error = :page_load

  # Debug mode disables concatenation and preprocessing of assets.
  # This option may cause significant delays in view rendering with a large
  # number of complex assets.
  config.assets.debug = true

  # Suppress logger output for asset requests.
  config.assets.quiet = true

  # Raises error for missing translations
  # config.action_view.raise_on_missing_translations = true

  # Use an evented file watcher to asynchronously detect changes in source code,
  # routes, locales, etc. This feature depends on the listen gem.
  config.file_watcher = ActiveSupport::EventedFileUpdateChecker
end

・test/mailers/previews/user_mailer_preview.rbファイル

# Preview all emails at http://localhost:3000/rails/mailers/user_mailer
class UserMailerPreview < ActionMailer::Preview

  # Preview this email at http://localhost:3000/rails/mailers/user_mailer/account_activation
  def account_activation
    user = User.first
    user.activation_token = User.new_token
    UserMailer.account_activation(user)
  end

  # Preview this email at http://localhost:3000/rails/mailers/user_mailer/password_reset
  def password_reset
    UserMailer.password_reset
  end

end

上記の２つです。

Answer 1

なぜだかわかりませんがきちんと表示されるようになりました。
URLが間違っていたか、test/mailers/previews/user_mailer_preview.rbファイルの中身が間違っていたかだと思います。

上述のファイルの中身をこのように書き換え、

# Preview all emails at http://localhost:3000/rails/mailers/user_mailer
class UserMailerPreview < ActionMailer::Preview

  # Preview this email at
  # http://localhost:3000/rails/mailers/user_mailer/account_activation
  def account_activation
    user = User.first
    user.activation_token = User.new_token
    UserMailer.account_activation(user)
  end

  # Preview this email at
  # http://localhost:3000/rails/mailers/user_mailer/password_reset
  def password_reset
    UserMailer.password_reset
  end
end

自分のベースのURLの後に以下のように入れました。

/rails/mailers/user_mailer/account_activation