Ruby on Rails Michael Hartl chapter 9 Test fails

I was finishing up Chapter 9 from the RoR Tutorial and I was running the last test and a Failure showed up from the code which ran green in the previous tests. I searched the whole web and cross check code everywhere but I wasnt able to resolve it.

FAILURE MESSAGE:

Failure: UserTest#test_email_validation_should_reject_invalid_address [/home/ubuntu/workspace/sample_app/test/models/user_test.rb:44]: "foo@bar..com"should be invalid

user_test.eb

require 'test_helper'

class UserTest < ActiveSupport::TestCase

  def setup
    @user = User.new(name: "Example User", email: "user@example.com", password: "foobar", password_confirmation: "foobar")
  end

  test "should be valid" do 
    assert @user.valid?
  end
  test "name should be present" do
    @user.name = "   "
    assert_not @user.valid?
  end

  test "email should be present" do
    @user.email = " "
    assert_not @user.valid?
  end

  test "name should not be too long" do
   @user.name = "a" * 51
   assert_not @user.valid?
  end

  test "email shouldnt be too long" do
    @user.email = "a" * 244 + "@example.com"
    assert_not @user.valid?
  end

  test "email validation should accept valid addresses" do
    valid_addresses = %w[user@example.com USER@foo.COM A_US-ER@foo.bar.org first.last@foo.jp alice+bob@baz.cn]
    valid_addresses.each do |valid_address|
      @user.email = valid_address
      assert @user.valid?, "#{valid_address.inspect} should be valid"
    end
  end

  test "email validation should reject invalid address" do
    invalid_addresses = %w[user@example,com user_at_org.foo user.name@example. foo@bar_baz.com foo@bar+baz.com foo@bar..com]
    invalid_addresses.each do |invalid_address|
      @user.email = invalid_address
      assert_not @user.valid?, "#{invalid_address.inspect}should be invalid"
    end
  end

  test "emails should be unique" do
    duplicate_user = @user.dup
    duplicate_user.email = @user.email.upcase
    @user.save
    assert_not duplicate_user.valid?
  end

  test "passwors should be present" do
    @user.password = @user.password_confirmation = " " * 6
    assert_not @user.valid?
  end

  test "password should have minimum length" do 
    @user.password = @user.password_confirmation = "a" * 5
    assert_not @user.valid?
  end

  test "authenticated? should return false for a user with nil digest" do
    assert_not @user.authenticated?('')
  end

end

User.eb

class User < ActiveRecord::Base
  attr_accessor :remember_token
  before_save { self.email = email.downcase }
  validates :name,  presence: true, length: { maximum: 50 }
  VALID_EMAIL_REGEX = /\A[\w+\-.]+@[a-z\d\-.]+\.[a-z]+\z/i
  validates :email, presence: true, length: { maximum: 255 },
                    format: { with: VALID_EMAIL_REGEX },
                    uniqueness: { case_sensitive: false }
  has_secure_password
  validates :password, presence: true, length: { minimum: 6 }

  # Returns the hash digest of the given string.
  def User.digest(string)
    cost = ActiveModel::SecurePassword.min_cost ? BCrypt::Engine::MIN_COST :
                                                  BCrypt::Engine.cost
    BCrypt::Password.create(string, cost: cost)
  end

  # Returns a random token.
  def User.new_token
    SecureRandom.urlsafe_base64
  end

  # Remembers a user in the database for use in persistent sessions.
  def remember
    self.remember_token = User.new_token
    update_attribute(:remember_digest, User.digest(remember_token))
  end

  # Returns true if the given token matches the digest.
  def authenticated?(remember_token)
    return false if remember_digest.nil? #Add this line
    BCrypt::Password.new(remember_digest).is_password?(remember_token)
  end

  # Forgets a user.
  def forget
    update_attribute(:remember_digest, nil)
  end
end

Help me out im stuck. Thanks in advance