current_user method is returning nil - ruby-on-rails

Question

I'm following Michael Hartl's book: "Ruby on Rails Tutorial 3". I have reached section 8.4.1 where he says:
newly logged in users are correctly remembered, as you can verify by
logging in, closing the browser, and checking that you’re still logged
in when you restart the sample application and revisit the sample
application.
when I go through these steps I'm not logged in i.e: I can log in but when I restart the browser and revisit the app I'm not logged in as it is supposed to be.(I'm using localhost:3000)
If you want, you can even inspect the browser cookies to see the
result directly
This one, however, works. I can verify that the cookie is saved successfully.
I have gone through this chapter several times, making sure that I'm following the exact same steps but still no luck.
Also the test is not red, I can logout at any time. I really don't know what to do. I have been trying several things but no luck. Excuse me if this is a simple question as I'm new to rails.
Edit: you can view the chapter here: Rails tutorial 3
Edit 2:
By adding some more tests, I can find that the problem is that current_user is returning nil (note: the problem is in the cookies not in the sessions):
session_helper.rb
module SessionsHelper
# Logs in the given user.
def log_in(user)
session[:user_id] = user.id
end
# Remembers a user in a persistent session.
def remember(user)
user.remember
cookies.permanent.signed[:user_id] = user.id
cookies.permanent[:remember_token] = user.remember_token
end
def forget user
user.forget
cookies.delete(:user_id)
cookies.delete(:remember_token)
end
# Returns the user corresponding to the remember token cookie.
def current_user
if (user_id = session[:user_id])
#current_user ||= User.find_by(id: user_id)
elsif (user_id = cookies.signed[:user_id])
user = User.find_by(id: user_id)
if user && user.authenticated?(cookies[:remember_token])
log_in user
#current_user = user
end
end
end
# Returns true if the user is logged in, false otherwise.
def logged_in?
!current_user.nil?
end
# Logs out the current user.
def log_out
forget current_user
session.delete(:user_id)
#current_user = nil
end
end
models/user.rb
class User < ActiveRecord::Base
attr_accessor :remember_token
before_save { self.email.downcase! }
validates :name, presence: true, length: {maximum: 50}
Valid_email_regex = /\A[\w+\-.]+#[a-z\d\-]+(\.[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, length: {minimum: 6}
def User.digest(string)
cost = ActiveModel::SecurePassword.min_cost ? BCrypt::Engine::MIN_COST :
BCrypt::Engine.cost
BCrypt::Password.create(string, cost: cost)
end
def User.new_token
SecureRandom.urlsafe_base64
end
def remember
self.remember_token = User.new_token
update_attribute(:remember_digest, User.digest(:remember_token))
end
def forget
update_attribute(:remember_digest, nil)
end
def authenticated?(remember_token)
return false if remember_digest.nil?
BCrypt::Password.new(remember_digest).is_password?(remember_token)
end
end
session_controller
# logging in a user by email and logging them out
class SessionsController < ApplicationController
def new
end
def create
user = User.find_by(email: params[:session][:email].downcase)
if user && user.authenticate(params[:session][:password])
log_in user
params[:session][:remember_me] == '1' ? remember(user) : forget(user)
redirect_to user
else
flash.now[:danger] = "Invalid email/password combination"
render 'new'
end
end
def destroy
log_out if logged_in?
redirect_to root_url
end
end
Any help is appreciated.

Answer 1

1) The ONLY difference I can see with my own code, is in the models/user.rb
in before_save I think you either do
{ self.email.downcase }
or
{ email.downcase! }
With this, I could not reproduce your problem though. And I don't see how it could affect the log in persistence.
2) The code you posted has implemented the 'remember me'-checkbox from 8.5
So, when you signed up, did you check the checkbox?