Rails教程(M.Hartl)-我收到两个错误,需要帮助

我的RubyonRails应用程序中有2个错误。我正在尝试完成Rails教程中的示例应用程序。

以下是我的错误:

1) Error:
UserMailerTest#test_account_activation:
ArgumentError: wrong number of arguments (1 for 0)    app/mailers/user_mailer.rb:3:in `account_activation'     test/mailers/user_mailer_test.rb:9:in `block in <class:UserMailerTest>'

2) Failure:
UserMailerTest#test_password_reset [/home/andy/Ruby_Projects/sam
ple_app/test/mailers/user_mailer_test.rb:21]: Expected: ["from@example.com"] Actual: ["noreply@example.com"]

这是我针对这两个问题的代码:

require 'test_helper'

class UserMailerTest < ActionMailer::TestCase

  test "account_activation" do
    user = users(:andy)
    user.activation_token = User.new_token
    mail = UserMailer.account_activation(user)
    assert_equal "Account activation", mail.subject
    assert_equal [user.email], mail.to
    assert_equal ["noreply@example.com"], mail.from
    assert_match user.name,               mail.body.encoded
    assert_match user.activation_token,   mail.body.encoded
    assert_match CGI::escape(user.email), 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

这是UserMailer.rb:

class UserMailer < ApplicationMailer

  def account_activation
    user = user
    mail to: user.email, subject: "Account activation"
  end

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

我一直在遵循教程,用教程中的内容检查我的代码,但仍然无法发现我做错了什么。如果你需要更多信息,请告诉我。我会尽力提供。