Implement basic login

Gemfile

@@ -65,4 +65,5 @@ end
 # Windows does not include zoneinfo files, so bundle the tzinfo-data gem
 gem 'tzinfo-data', platforms: [:mingw, :mswin, :x64_mingw, :jruby]
 gem 'bootstrap-sass', '~> 3.3', '>= 3.3.7'
-gem 'bcrypt', '~> 3.1', '>= 3.1.12'
\ No newline at end of file
+gem 'bcrypt', '~> 3.1', '>= 3.1.12'
+gem 'jquery-rails', '~> 4.3', '>= 4.3.3'
\ No newline at end of file

Gemfile.lock

@@ -90,6 +90,10 @@ GEM
     jbuilder (2.7.0)
       activesupport (>= 4.2.0)
       multi_json (>= 1.2)
+    jquery-rails (4.3.3)
+      rails-dom-testing (>= 1, < 3)
+      railties (>= 4.2.0)
+      thor (>= 0.14, < 2.0)
     listen (3.1.5)
       rb-fsevent (~> 0.9, >= 0.9.4)
       rb-inotify (~> 0.9, >= 0.9.7)
@@ -211,6 +215,7 @@ DEPENDENCIES
   chromedriver-helper
   coffee-rails (~> 4.2)
   jbuilder (~> 2.5)
+  jquery-rails (~> 4.3, >= 4.3.3)
   listen (>= 3.0.5, < 3.2)
   pg (~> 1.0)
   puma (~> 3.11)

app/assets/javascripts/application.js

-// This is a manifest file that'll be compiled into application.js, which will include all the files
-// listed below.
-//
-// Any JavaScript/Coffee file within this directory, lib/assets/javascripts, or any plugin's
-// vendor/assets/javascripts directory can be referenced here using a relative path.
-//
-// It's not advisable to add code directly here, but if you do, it'll appear at the bottom of the
-// compiled file. JavaScript code in this file should be added after the last require_* statement.
-//
-// Read Sprockets README (https://github.com/rails/sprockets#sprockets-directives) for details
-// about supported directives.
-//
+//= require jquery
+//= require bootstrap
 //= require rails-ujs
 //= require activestorage
 //= require turbolinks

app/assets/stylesheets/application.css

-/*
-= require_self
-= require 'custom'
-*/
\ No newline at end of file

app/assets/stylesheets/application.scss

+@import 'custom';
\ No newline at end of file

app/controllers/application_controller.rb

 class ApplicationController < ActionController::Base
   protect_from_forgery with: :exception
-
-  def hello
-    render html: "hello, world!"
-  end
+  include SessionsHelper
 end

app/controllers/sessions_controller.rb

+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
+      redirect_to user
+    else
+      flash.now[:danger] = "Invalid email/password combination"
+      render 'new'
+    end
+  end
+
+  def destroy
+    log_out
+    redirect_to root_url
+  end
+end

app/controllers/users_controller.rb

 class UsersController < ApplicationController
   def show
     @user = User.find(params[:id])
-    # debugger
   end
 
   def new
@@ -11,6 +10,7 @@ class UsersController < ApplicationController
   def create
     @user = User.new(user_params)
     if @user.save
+      log_in @user
       flash[:success] = "Welcome to the Sample App!"
       redirect_to @user
     else

app/helpers/sessions_helper.rb

+module SessionsHelper
+  def log_in(user)
+    session[:user_id] = user.id
+  end
+
+  def current_user
+    @current_user ||= User.find_by(id: session[:user_id])
+  end
+
+  def logged_in?
+    !current_user.nil?
+  end
+
+  def log_out
+    session.delete(:user_id)
+    @current_user = nil
+  end
+end

app/models/user.rb

@@ -8,4 +8,10 @@ class User < ApplicationRecord
 
   has_secure_password
   validates :password, presence: true, 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
 end

app/views/layouts/_header.html.erb

@@ -5,7 +5,24 @@
       <ul class="nav navbar-nav navbar-right">
         <li><%= link_to 'Home',   root_path %></li>
         <li><%= link_to 'Help',   help_path %></li>
-        <li><%= link_to 'Log in', '#' %></li>
+        <% if logged_in? %>
+          <li><%= link_to "Users", '#' %></li>
+          <li class="dropdown">
+            <a href="#" class="dropdown-toggle" data-toggle="dropdown">
+              Account <b class="caret"></b>
+            </a>
+            <ul class="dropdown-menu">
+              <li><%= link_to "Profile", current_user %></li>
+              <li><%= link_to "Settings", "#" %></li>
+              <li class="divider"></li>
+              <li>
+                <%= link_to "Log out", logout_path, method: :delete %>
+              </li>
+            </ul>
+          </li>
+        <% else %>  
+          <li><%= link_to 'Log in', login_path %></li>
+        <% end %>
       </ul>
     </nav>
   </div>

app/views/sessions/new.html.erb

+<% provide(:title, 'Log in') %>
+<h1>Log in</h1>
+
+<div class="row">
+  <div class="col-md-6 col-md-offset-3">
+    <%= form_for :session, url: login_path do |f| %>
+      <%= f.label :email %>
+      <%= f.email_field :email, class: 'form-control' %>
+
+      <%= f.label :password %>
+      <%= f.password_field :password, class: 'form-control' %>
+
+      <%= f.submit 'Log in', class: "btn btn-primary" %>
+    <% end %>
+
+    <p>New user? <%= link_to 'Sign up now!', signup_path %></p>
+  </div>
+</div>
\ No newline at end of file

config/routes.rb

@@ -3,7 +3,13 @@ Rails.application.routes.draw do
   get '/help',    to: 'static_pages#help'
   get '/about',   to: 'static_pages#about'
   get '/contact', to: 'static_pages#contact'
+  
   get '/signup',  to: 'users#new'
   post '/signup', to: 'users#create'
+
+  get '/login',   to: 'sessions#new'
+  post '/login',   to: 'sessions#create'
+  delete '/logout',  to: 'sessions#destroy'
+
   resources :users
 end

test/controllers/sessions_controller_test.rb

+require 'test_helper'
+
+class SessionsControllerTest < ActionDispatch::IntegrationTest
+  test "should get new" do
+    get login_path
+    assert_response :success
+  end
+
+end

test/fixtures/users.yml

+michael:
+  name: Michael Example
+  email: michael@example.com
+  password_digest: <%= User.digest('password') %>
\ No newline at end of file

test/integration/users_login_test.rb

+require 'test_helper'
+
+class UsersLoginTest < ActionDispatch::IntegrationTest
+  def setup
+    @user = users(:michael)
+  end
+  
+  test "login with invalid information" do
+    get login_path
+    assert_template 'sessions/new'
+    post login_path, params: { session: { email: "", password: "" } }
+    assert_template 'sessions/new'
+    assert_not flash.empty?
+    get root_path
+    assert flash.empty?
+  end
+
+  test "login with valid information followed by logout" do
+    get login_path
+    post login_path, params: { session: { email: @user.email, 
+                                          password: 'password' } }
+    assert is_logged_in?  
+    assert_redirected_to @user
+    follow_redirect!
+    assert_template 'users/show'                                          
+    assert_select "a[href=?]", login_path, count: 0
+    assert_select "a[href=?]", logout_path
+    assert_select "a[href=?]", user_path(@user)
+    delete logout_path
+    assert_not is_logged_in?
+    assert_redirected_to root_url
+    follow_redirect!
+    assert_select "a[href=?]", login_path
+    assert_select "a[href=?]", logout_path, count: 0
+    assert_select "a[href=?]", user_path(@user), count: 0
+  end
+end

test/integration/users_signup_test.rb

@@ -4,14 +4,14 @@ class UsersSignupTest < ActionDispatch::IntegrationTest
   test "invalid signup information" do
     get signup_path
     assert_no_difference 'User.count' do
-      post users_path, params: { user: {name: "",
+      post signup_path, params: { user: {name: "",
                                 email: "user@invalid",
                                 password: "foo",
                                 password_confirmation: "bar" } }
     end
     assert_template 'users/new'
-    assert_select 'div#<CSS id for error explanation>'
-    assert_select 'div.<CSS class for field with error>'
+    assert_select 'div#error_explanation'
+    assert_select 'div.field_with_errors'
   end
 
   test "valid signup information" do
@@ -24,5 +24,6 @@ class UsersSignupTest < ActionDispatch::IntegrationTest
     end
     follow_redirect!
     assert_template 'users/show'
+    assert is_logged_in?
   end
 end

test/test_helper.rb

@@ -5,5 +5,10 @@ require 'rails/test_help'
 class ActiveSupport::TestCase
   # Setup all fixtures in test/fixtures/*.yml for all tests in alphabetical order.
   fixtures :all
-  # Add more helper methods to be used by all tests here...
+  
+
+  #return true if a test user is logged in.
+  def is_logged_in?
+    !session[:user_id].nil?
+  end
 end