Railsチュートリアル第１１章にてメールプレビューにアクセスできない

コード


config/environments/development.rbファイル

Rails.application.configure do
 
  config.cache_classes = false


  config.eager_load = false

  
  config.consider_all_requests_local = true

  
  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

  # Don't care if the mailer can't send.
  config.action_mailer.raise_delivery_errors = true
  config.action_mailer.delivery_method = :test
  host = '自分のホスト名'     # クラウドIDE
  config.action_mailer.default_url_options = { host: host, protocol: 'https' }

 略

end

app/mailers/application_mailer.rbファイル

class ApplicationMailer < ActionMailer::Base
  default from: "noreply@example.com"
  layout 'mailer'
end


app/mailers/user_mailer.rbファイル

class UserMailer < ApplicationMailer

  # Subject can be set in your I18n file at config/locales/en.yml
  # with the following lookup:
  #
  #   en.user_mailer.account_activation.subject
  #
  def account_activation(user)
    @user = user
    mail to: user.email, subject: "Account activation"
  end
  # Subject can be set in your I18n file at config/locales/en.yml
  # with the following lookup:
  #
  #   en.user_mailer.password_reset.subject
  #
  def password_reset
    @greeting = "Hi"

    mail to: "to@example.org"
  end
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

実行結果

以下URLのプレビューページへアクセスを試みるも、、、

http://自分のホスト名/rails/mailers/user_mailer/account_activation

このようなエラー画面になる。

テストの実行結果

ERROR["test_account_activation", UserMailerTest, 1.4476014219999342]
 test_account_activation#UserMailerTest (1.45s)
ArgumentError:         ArgumentError: wrong number of arguments (given 0, expected 1)
            app/mailers/user_mailer.rb:8:in `account_activation'
            test/mailers/user_mailer_test.rb:6:in `block in <class:UserMailerTest>'

 FAIL["test_password_reset", UserMailerTest, 1.459731961999978]
 test_password_reset#UserMailerTest (1.46s)
        Expected: ["from@example.com"]
          Actual: ["noreply@example.com"]
        test/mailers/user_mailer_test.rb:16:in `block in <class:UserMailerTest>'

  43/43: [===============================] 100% Time: 00:00:01, Time: 00:00:01

Finished in 1.46772s
43 tests, 167 assertions, 1 failures, 1 errors, 0 skips

解決法分かる方ご享受願います。