UserMailerTest引發ArgumentError：錯誤的參數數目（0 1）

Question

我的工作軌道上的教程紅寶石的第10章，並獲得了後續錯誤：

UserMailerTest#test_account_activation: 
ArgumentError: wrong number of arguments (0 for 1) 
app/mailers/user_mailer.rb:3:in `account_activation' 
test/mailers/user_mailer_test.rb:6:in `block in <class:UserMailerTest>' 

我不知道是什麼原因造成由於代碼與教程中的代碼相同，所以錯誤。有任何想法嗎？

user_mailer.rb

class UserMailer < ApplicationMailer 
def account_activation(user) 
    @user = user 
    mail to: user.email, subject: "Account activation" 
end 

def password_reset 
    @greeting = "Hi" 
    mail to: "to@example.org" 
    end 
end 

application_mailer.rb

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

的routes.rb

Rails.application.routes.draw do 

get 'sessions/new' 

root 'welcome#index' 

get 'contact' => 'welcome#contact' 
get 'about' => 'welcome#about' 
get 'signup' => 'users#new' 
get 'login' => 'sessions#new' 
post 'login' => 'sessions#create' 
delete 'logout' => 'sessions#destroy' 

resources :users 
resources :account_activations, only: [:edit] 
match ':controller(/:action(/:id))', :via => :get 
end 

user_mailer_test.rb

require 'test_helper' 

class UserMailerTest < ActionMailer::TestCase 
test "account_activation" do 
    mail = UserMailer.account_activation 
    assert_equal "Account activation", mail.subject 
    assert_equal ["to@example.org"], mail.to 
    assert_equal ["from@example.com"], mail.from 
    assert_match "Hi", mail.body.encoded 
end 

test "password_reset" do 
    mail = UserMailer.password_reset 
    assert_equal "Password reset", mail.subject 
    assert_equal ["to@example.org"], mail.to 
    assert_equal ["from@example.com"], mail.from 
    assert_match "Hi", mail.body.encoded 
end 

end 

謝謝！

Answer 1

在測試中，您打電話給UserMailer.account_activation，但該方法需要一個用戶參數，因此您需要傳遞一個參數。