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Ruby on Rails Tutorial Exercise Answers
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01_ror_tutorial_exercise_answers.md

Ruby on Rails Tutorial Exercise Answers

Chapter 1

Section 1.1.1

  1. https://rubygems.org hosts the Ruby gem for Ruby on Rails.
  2. The current stable version number of Rails is 5.1.4, with 5.2.0.beta2 being the overall latest version.
  3. As of this writing, Ruby on Rails has been downloaded 118,011,892 across all versions.

Section 1.3.2

  1. The current version of Ruby on my system in 2.5.0 (ruby -v reports ruby 2.5.0p0 (2017-12-25 revision 61468) [x86_64-darwin17]).
  2. The current version of Rails on my system is 5.1.4.

Section 1.3.4

  1. Doing so changes the contents of the hello method to be render html: "hola, mundo!".
  2. Doing so changes the contents of the hello method to be render html: "¡Hola, mundo!".
  3. Doing so adds a goodbye method with the contents render html: "goodbye, world" and modifies the root route line in router.rb to read root 'application#goodbye'.

Section 1.5.3

  1. In the current state of the project, getting the production version of the app to show "hola, mundo!" simply required the text to be altered from "¡Hola, mundo!" in the hello method inside the application controller (remove the inverted question mark and change the H in Hola to lowercase) and modifying the root route to point to the hello method in the ApplicationController. After these changes had been committed, running $ git push heroku updated the live site with these changes.
  2. Switching the root route in routes.rb to point back to the goodbye method in the application controller (application#goodbye), committing the change, and pushing it to heroku was all that was required for this exercise.

Section 1.5.4

  1. The command to display logs is $ heroku logs.
  2. The most recent event was (line breaks added for readability):
2018-01-07T04:55:46.209028+00:00 app[web.1]: I, [2018-01-07T04:55:46.208969 #4] 
INFO -- : [11747d4f-ddad-45be-b5a5-51a288465c2e]
Completed 200 OK in 8ms (Views: 0.9ms)

Chapter 2

Section 2.2.1

  1. The CSS id for the text “User was successfully created.” is notice. When you refresh the browser, the text goes away.
  2. When you try to create a user with a name but no email address, the creation of the user is successful, with no email address being set for the user.
  3. When you try create a user with an invalid email address, the user is successfully created with the invalid email address populating the email field of the user.
  4. By default, Rails displays "User was successfully destroyed." when a user is destroyed.

Section 2.2.2

  1. The steps for visiting /users/1/edit are as follows:
    1. The browser issues a request for the /users/1/edit URL.
    2. Rails routes /users/1/edit to the edit action in the Users controller.
    3. The edit action asks the User model to retrieve the user with an id of 1 (User.find(params[:id])).
    4. The User model pulls the specified user from the database.
    5. The User model returns the single users to the controller.
    6. The controller captures the user in the @user variable, which is passed to the edit view.
    7. The view uses embedded Ruby to render the page as HTML.
    8. The controller passes the HTML back to the browser.
  2. The line in the scaffolding code that retrieves the user from the database is @user = User.find(params[:id]).
  3. The name of the view file for the user edit page is edit.html.erb.

Section 2.3.1

  1. The CSS id for the text “Micropost was successfully created.” is notice. When you refresh the browser, the text goes away.
  2. When you try to create a micropost with empty content and no user id, the creation of the micropost is successful, with no content or user id being set for the micropost.
  3. The micropost with the content length set to over 140 characters successfully creates.
  4. Destroying these microposts removes them and displays "Micropost was successfully destroyed." in the flash.

Section 2.3.2

  1. Microposts with a content length longer than 140 trigger a validation error and fail to create.
  2. The CSS id of the error message produced by the previous exercise is error_explanation.

Section 2.3.3

  1. To complete this exercise, I added the following to the bottom of app/views/users/edit.html.erb:

    <h2>First Micropost</h2>
<%= @user.microposts.first.content %>

  2. The validation error message that shows when presence: true is included on the Micropost's model content validation is "Content can't be blank".

  3. The user model reads as follows after completing this exercise: To complete this exercise, I added the following to the bottom of app/views/users/edit.html.erb:

    class User < ApplicationRecord
  has_many :microposts
  validates :name, presence: true
  validates :email, presence: true
end

Section 2.3.4

  1. The line that causes ApplicationController to inherit from ActionController::Base is class ApplicationController < ActionController::Base.

  2. The analogous file containing a line where ApplicationRecord inherits from ActiveRecord::Base is app/models/application_record.rb:

    class ApplicationRecord < ActiveRecord::Base
  self.abstract_class = true
end

Section 2.3.5

  1. Create 2nd and third users Foo Bar (foo@bar.com) and Baz Quux (baz@quux.com).
  2. Create Second post and Third post for the first user.
  3. Confirmed that the validation from Listing 2.13 works on the production app.

Chapter 3

Section 3.1

  1. I did not use bitbucket, but the page does correctly show here on GitHub.
  2. The deployment to Heroku did succeed.

Section 3.2.1

  1. Output:
$ rails g controller FooController bar baz
Running via Spring preloader in process 51437
      create  app/controllers/foo_controller_controller.rb
      ...
      create      app/assets/stylesheets/foo_controller.scss
  1. Output:
$ rails d controller FooController bar baz
Running via Spring preloader in process 51465
      ...
      remove      app/assets/stylesheets/foo_controller.scss

Section 3.4.2

  1. Changing the StaticPageController tests to use the @base_title instance variable still correctly shows all tests passing.

Section 3.4.3

  1. Work for the exercise can be viewed in these two commits: dd51f1c and a0e388e.

Section 3.4.4

  1. Work for this exercise can be viewed in this commit: 2a31cef.

Chapter 4

Section 4.2.2

>> city = 'Charleston'
=> "Charleston"
>> state = "South Carolina"
=> "South Carolina
>> puts "#{city}, #{state}"
"Charleston, South Carolina"
=> nil
>> puts "#{city}\t#{state}"
Charleston	South Carolina
=> nil
>> puts '#{city}\t#{state}'
#{city}\t#{state}
=> nil

Section 4.2.3

>> "racecar".length
=> 7
>> "racecar".reverse
=> "racecar"
>> s = "racecar"
=> "racecar"
>> s == s.reverse
=> true
>> s = "onomatopoeia"            
=> "onomatopoeia"
>> s == s.reverse    
=> false

Section 4.2.4

>> def palindrome_tester(s)
>>   if s == s.reverse
>>     puts "It's a palindrome!"
>>   else
>>     puts "It's not a palindrome."
>>   end
>> end
>> palindrome_tester("racecar")
It's a palindrome!
=> nil
>> palindrome_tester("onomatopoeia")
It's not a palindrome.
=> nil
>> palindrome_tester("racecar").nil? 
It's a palindrome!
=> true

Section 4.3.1

>> a = "A man, a plan, a canal, Panama".split(', ')
=> ["A man", "a plan", "a canal", "Panama"]
>> s = a.join
=> "A mana plana canalPanama"
>> s = a.join
=> "A mana plana canalPanama"
>> s = s.split.join
=> "AmanaplanacanalPanama"
>> s == s.reverse
=> false
>> s.downcase == s.reverse.downcase
=> true
>> ('a'..'z').to_a[7]        
=> "h"
>> ('a'..'z').to_a.reverse[7]
=> "s"

Section 4.3.2

>> (0..16).each { |i| puts i ** 2 }
0
1
4
...
256
=> 0..16
>> def yeller(char_arr)
>>   char_arr.map(&:upcase).join
>> end
=> :yeller
>> yeller(['o', 'l', 'd'])
=> "OLD"
>> def random_subdomain
>>   ('a'..'z').to_a.sample(8).join
>> end
=> :random_subdomain
>> random_subdomain
=> "rsbpxjgf"
>> def random_subdomain
>>   ('a'..'z').to_a.sample(8).join
>> end
=> :random_subdomain
>> random_subdomain
=> "rsbpxjgf"

Section 4.3.3

>> hash = { 'one' => 'uno', 'two' => 'dos', 'three' => 'tres' }
=> {"one"=>"uno", "two"=>"dos", "three"=>"tres"}
>> hash.each do |key, value|
?>   puts "'#{key}' in Spanish is '#{value}'"
>> end
'one' in Spanish is 'uno'
'two' in Spanish is 'dos'
'three' in Spanish is 'tres'
=> {"one"=>"uno", "two"=>"dos", "three"=>"tres"}
>> person1 = { first: "Dwayne", last: "Lusk" }
=> {:first=>"Dwayne", :last=>"Lusk"}
>> person2 = { first: "Susan", last: "Lusk" }
=> {:first=>"Susan", :last=>"Lusk"}
>> person3 = { first: "Josh", last: "Lusk" }
=> {:first=>"Josh", :last=>"Lusk"}
>> params = { father: person1, mother: person2, child: person3 }
=> {:father=>{:first=>"Dwayne", :last=>"Lusk"}, :mother=>{:first=>"Susan", :last=>"Lusk"}, :child=>{:first=>"Josh", :last=>"Lusk"}}
>> params[:father][:first]
=> "Dwayne"
>> user = { name: "Josh Lusk", email: "josh@example.com", password_digest: "lybfcdsopjbcxsdf" }
=> {:name=>"Josh Lusk", :email=>"josh@example.com", :password_digest=>"lybfcdsopjbcxsdf"}
>> { "a" => 100, "b" => 200 }.merge({ "b" => 300 })
=> {"a"=>100, "b"=>300}

Section 4.4.1

  1. (0..10) is the literal constructor for the range of integers from 1 to 10
  2. Range.new(0, 10) is the constructor using the Range class and the new method.
>> (0..10) == Range.new(0, 10)
=> true

Section 4.4.2

  1. The class hierarchy for a range is Range -> Class -> Module -> Object -> BasicObject, the class hierarchy for a hash is Hash -> Class -> Module -> Object -> BasicObject, and the class hierarchy for a symbol is Symbol -> Class -> Module -> Object -> BasicObject.
>> class Word < String
>>   def palindrome?
>>     self == reverse
>>   end
>> end
=> :palindrome?
>> Word.new('level').palindrome?
=> true

Section 4.4.3

>> "racecar".palindrome?
=> true
>> "onomatopoeia".palindrome?
=> false
>> "Malayalam".downcase.palindrome?
=> true
>> class String
>>   def shuffle
>>     self.split('').shuffle.join
>>   end
>> end
=> :shuffle
>> "foobar".shuffle
=> "rbfooa"
>> class String
>>   def shuffle
>>     split('').shuffle.join
>>   end
>> end
=> :shuffle
>> "foobar".shuffle
=> "oabfro"

Section 4.4.4

>> user = User.new
=> #<User id: nil, name: nil, email: nil, created_at: nil, updated_at: nil>
user.class
=> User(id: integer, name: string, email: string, created_at: datetime, updated_at: datetime)
>> user.class.superclass
=> ApplicationRecord(abstract)
>> user.class.superclass.superclass
=> ActiveRecord::Base
>> user.class.superclass.superclass.superclass
=> Object

Section 4.4.5

class User
	attr_accessor :first_name, :last_name, :email

	def initialize(attributes = {})
		@first_name = attributes[:first_name]
		@last_name = attributes[:last_name]
		@email = attributes[:email]
	end

	def full_name
		"#{@first_name} #{@last_name}"
	end

	def formatted_email
		"#{full_name} <#{@email}>"
	end
end
def alphabetical_name
   "#{@last_name}, #{@first_name}"
end
>> require './example_user'
=> true
>> user = User.new(first_name: "Josh", last_name: "Lusk")
=> #<User:0x00007f855acf1958 @first_name="Josh", @last_name="Lusk", @email=nil>
>> user.full_name.split == user.alphabetical_name.split(', ').reverse
=> true

Chapter 5

Section 5.1.1

  1. $ curl -OL cdn.learnenough.com/kitten.jpg
  2. $ mv kitten.jpg app/assets/images/kitten.jpg
  3. <%= image_tag("kitten.png", alt: "Kitten") %>

Section 5.1.2

  1. <%#= image_tag("kitten.jpg", alt: "Kitten") %>
img {
  display: none;
}

Section 5.1.3

  1. Adding the rails_default partial acted as expected.
StaticPagesControllerTest#test_should_get_contact:
ActionView::Template::Error: Missing partial layouts/_rails_default with {:locale=>[:en], :formats=>[:html], :variants=>[], :handlers=>[:raw, :erb, :html, :builder, :ruby, :coffee, :jbuilder]}. Searched in:
  * "/Users/joshualusk/Code/sample_app/app/views"
  1. 5 runs, 9 assertions, 0 failures, 0 errors, 0 skips

Section 5.2.4

  1. The CSS for the footer has been converted to SCSS.

Section 5.3.2

  1. get '/help', to: 'static_pages#help', as: 'helf'
test "should get help" do
  get helf_path
  assert_response :success
  assert_select "title", "Help | #{@base_title}"
end
  1. Changes successfully reverted and tests passing.

Section 5.3.3

  1. <li><%= link_to "Help", helf_path %></li>
  2. Changes successfuly reverted.

Section 5.3.4

<li><%= link_to "About", contact_path %></li>
<li><%= link_to "Contact", contact_path %></li>
test "full title helper" do
  assert_equal full_title,         "Ruby on Rails Tutorial Sample App"
  assert_equal full_title("Help"), "Help | Ruby on Rails Tutorial Sample App"
end

Section 5.4.1

  1. In config/routes.rb:
get 'users/new', as: 'signup'

In test/controllers/users_controller_test.rb:

test "should get new" do
  get signup_path
  assert_response :success
end
  1. The temporary config/routes.rb change does allow the tests to pass.

Section 5.4.2

  1. I did solve the exercise in Section 5.4.1.1.
  2. Test verified to work by commenting out /signup route.
get signup_path
assert_select "title", full_title("Sign up")

Chapter 6

Section 6.1.1

  1. db/schema.db contains a similar create_table command to the migration file, along with other lines of code:
ActiveRecord::Schema.define(version: 20180117172914) do

  # These are extensions that must be enabled in order to support this database
  enable_extension "plpgsql"

  create_table "users", force: :cascade do |t|
    t.string "name"
    t.string "email"
    t.datetime "created_at", null: false
    t.datetime "updated_at", null: false
  end

end
  1. Code contents of db/schema.db after running $ rails db:rollback:
ActiveRecord::Schema.define(version: 0) do

  # These are extensions that must be enabled in order to support this database
  enable_extension "plpgsql"

end
  1. After running $ rails db:migrate, db/schema.rb looks the same as listed in exercise 1.

Section 6.1.2

>> user = User.new
=> #<User id: nil, name: nil, email: nil, created_at: nil, updated_at: nil>
>> user.class
=> User(id: integer, name: string, email: string, created_at: datetime, updated_at: datetime)
>> user.class.superclass
=> ApplicationRecord(abstract)
>> user.class.superclass.superclass
=> ActiveRecord::Base

Section 6.1.3

>> user.name.class
=> String
>> user.email.class
=> String
>> user.created_at.class
=> ActiveSupport::TimeWithZone
>> user.updated_at.class
=> ActiveSupport::TimeWithZone

Section 6.1.4

>> User.find_by(name: 'Josh Lusk')
  User Load (0.4ms)  SELECT  "users".* FROM "users" WHERE "users"."name" = $1 LIMIT $2  [["name", "Josh Lusk"], ["LIMIT", 1]]
=> #<User id: 1, name: "Josh Lusk", email: "josh@example.com", created_at: "2018-01-17 17:52:01", updated_at: "2018-01-17 17:52:01">
>> User.find_by_name('Josh Lusk')
  User Load (0.4ms)  SELECT  "users".* FROM "users" WHERE "users"."name" = $1 LIMIT $2  [["name", "Josh Lusk"], ["LIMIT", 1]]
=> #<User id: 1, name: "Josh Lusk", email: "josh@example.com", created_at: "2018-01-17 17:52:01", updated_at: "2018-01-17 17:52:01">
>> User.all.class
=> User::ActiveRecord_Relation
>> User.all.length
  User Load (0.5ms)  SELECT "users".* FROM "users"
=> 2

Section 6.1.5

>> user.name = "Josh Lusk"
=> "Josh Lusk"
>> user.save
   (0.3ms)  SAVEPOINT active_record_1
  SQL (0.5ms)  UPDATE "users" SET "name" = $1, "updated_at" = $2 WHERE "users"."id" = $3  [["name", "Josh Lusk"], ["updated_at", "2018-01-17 18:09:58.956613"], ["id", 1]]
   (0.2ms)  RELEASE SAVEPOINT active_record_1
=> true
>> user.update_attributes(email: 'josh@example.com')
   (0.3ms)  SAVEPOINT active_record_1
  SQL (0.5ms)  UPDATE "users" SET "email" = $1, "updated_at" = $2 WHERE "users"."id" = $3  [["email", "josh@example.com"], ["updated_at", "2018-01-17 18:10:25.000923"], ["id", 1]]
   (0.2ms)  RELEASE SAVEPOINT active_record_1
=> true
>> user.created_at = 1.year.ago
=> Tue, 17 Jan 2017 18:10:51 UTC +00:00
>> user.save
   (0.3ms)  SAVEPOINT active_record_1
  SQL (0.6ms)  UPDATE "users" SET "created_at" = $1, "updated_at" = $2 WHERE "users"."id" = $3  [["created_at", "2017-01-17 18:10:51.168168"], ["updated_at", "2018-01-17 18:10:53.677700"], ["id", 1]]
   (0.3ms)  RELEASE SAVEPOINT active_record_1
=> true

Section 6.2.1

>> User.new(name: "Example User", email: "user@example.com").valid?
=> true
>> User.new.valid?
=> true

Section 6.2.2

>> u = User.new
=> #<User id: nil, name: nil, email: nil, created_at: nil, updated_at: nil>
>> u.valid?
=> false
>> u.errors.full_messages
=> ["Name can't be blank", "Email can't be blank"]
>> u.errors.messages
=> {:name=>["can't be blank"], :email=>["can't be blank"]}
>> u.errors.messages.class == Hash
=> true
>> u.errors[:email]
=> ["can't be blank"]

Section 6.2.3

>> user = User.new(name: "a" * 51, email: "a" * 244 + "@example.com")
=> #<User id: nil, name: "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa...", email: "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa...", created_at: nil, updated_at: nil>
>> user.valid?
=> false
>> user.errors.full_messages
=> ["Name is too long (maximum is 50 characters)", "Email is too long (maximum is 255 characters)"]

Section 6.2.4

  1. rubular
$ rails test:models
Started with run options --seed 41153

Run options: --seed 41153--=---=---=---=---=--] 0% Time: 00:00:00,  ETA: ??:??:??

# Running:

.....  7/6: [===============================      ] 85% Time: 00:00:00,  ETA: 00:.  7/7: [====================================] 100% Time: 00:00:00, Time: 00:00:00
.
Finished in 0.04103s
7 tests, 16 assertions, 0 failures, 0 errors, 0 skips



Finished in 0.054347s, 128.8020 runs/s, 294.4045 assertions/s.
7 runs, 16 assertions, 0 failures, 0 errors, 0 skips
  1. rubular

Section 6.2.5

  1. Solution presented in Listing 6.33.
  2. The before_save callback can be written as before_save { email.downcase! } to modify the email attribute directly.

Section 6.3.2

>> user = User.new(name: "Example User", email: "user@example.com")
=> #<User id: nil, name: "Example User", email: "user@example.com", created_at: nil, updated_at: nil, password_digest: nil>
>> user.valid?
  User Exists (1.6ms)  SELECT  1 AS one FROM "users" WHERE LOWER("users"."email") = LOWER($1) LIMIT $2  [["email", "user@example.com"], ["LIMIT", 1]]
=> false
>> user.errors.full_messages
=> ["Password can't be blank"]
>>

Section 6.3.3

>> user = User.new(name: "Example User", email: "user@example.com", password: "a" * 5, password_confirmation: "a" * 5)
=> #<User id: nil, name: "Example User", email: "user@example.com", created_at: nil, updated_at: nil, password_digest: "$2a$10$2YbdzqoPAuIralVqoHzaBO.PfPqA2547P.UxMYgEy9D...">
>> user.valid?
  User Exists (0.6ms)  SELECT  1 AS one FROM "users" WHERE LOWER("users"."email") = LOWER($1) LIMIT $2  [["email", "user@example.com"], ["LIMIT", 1]]
=> false
>> user.errors.full_messages
=> ["Password is too short (minimum is 6 characters)"]

Section 6.3.4

>> user = User.find_by(email: "jlusk@example.com")
  User Load (0.5ms)  SELECT  "users".* FROM "users" WHERE "users"."email" = $1 LIMIT $2  [["email", "jlusk@example.com"], ["LIMIT", 1]]
=> #<User id: 6, name: "Josh Lusk", email: "jlusk@example.com", created_at: "2018-01-17 20:30:34", updated_at: "2018-01-17 20:30:34", password_digest: "$2a$10$PzRIAXrzLt7r22udGGJIAefVk7I.6VMXnuWc62mX2Th...">
  1. The call to save did not work because the validations around the password virtual attribute were not met.
>> user.name = "Josh H. Lusk"
=> "Josh H. Lusk"
>> user.save
   (0.3ms)  BEGIN
  User Exists (0.6ms)  SELECT  1 AS one FROM "users" WHERE LOWER("users"."email") = LOWER($1) AND ("users"."id" != $2) LIMIT $3  [["email", "jlusk@example.com"], ["id", 6], ["LIMIT", 1]]
   (0.2ms)  ROLLBACK
=> false
>> user.errors.full_messages
=> ["Password can't be blank", "Password is too short (minimum is 6 characters)"]
>> user.update_attribute(:name, "Josh H. Lusk")
   (0.3ms)  BEGIN
  SQL (0.7ms)  UPDATE "users" SET "name" = $1, "updated_at" = $2 WHERE "users"."id" = $3  [["name", "Josh H. Lusk"], ["updated_at", "2018-01-17 20:39:54.809455"], ["id", 6]]
   (2.3ms)  COMMIT
=> true

Chapter 7

Section 7.1.1

  1. The controller and action of the params hash for /about are static_pages and about, respectively.
>> user = User.first 
  User Load (0.5ms)  SELECT  "users".* FROM "users" ORDER BY "users"."id" ASC LIMIT $1  [["LIMIT", 1]]
=> #<User id: 1, name: "Example User", email: "user@example.com", created_at: "2018-01-21 04:05:46", updated_at: "2018-01-21 04:05:46", password_digest: "$2a$10$Nzw7IByN9Y23cUP3zPf/SOpcGTvPoOlN.eYPlF2ayRY...">
>> puts user.attributes.to_yaml
---
id: 1
name: Example User
email: user@example.com
created_at: !ruby/object:ActiveSupport::TimeWithZone
  utc: &1 2018-01-21 04:05:46.891622000 Z
  zone: &2 !ruby/object:ActiveSupport::TimeZone
    name: Etc/UTC
  time: *1
updated_at: !ruby/object:ActiveSupport::TimeWithZone
  utc: &3 2018-01-21 04:05:46.891622000 Z
  zone: *2
  time: *3
password_digest: "$2a$10$Nzw7IByN9Y23cUP3zPf/SOpcGTvPoOlN.eYPlF2ayRYPL6tgpfnje"
=> nil
>> y user.attributes
---
id: 1
name: Example User
email: user@example.com
created_at: !ruby/object:ActiveSupport::TimeWithZone
  utc: &1 2018-01-21 04:05:46.891622000 Z
  zone: &2 !ruby/object:ActiveSupport::TimeZone
    name: Etc/UTC
  time: *1
updated_at: !ruby/object:ActiveSupport::TimeWithZone
  utc: &3 2018-01-21 04:05:46.891622000 Z
  zone: *2
  time: *3
password_digest: "$2a$10$Nzw7IByN9Y23cUP3zPf/SOpcGTvPoOlN.eYPlF2ayRYPL6tgpfnje"
=> nil

Section 7.1.2

<%= @user.name %>, <%= @user.email %> <br>
Created at <%= @user.created_at %>, updated last at <%= @user.updated_at %>.
  1. Refreshing the browser with the time code embedded (see below) reevaluates/redisplays the current time.
<%= @user.name %>, <%= @user.email %> <br>
Created at <%= @user.created_at %>, updated last at <%= @user.updated_at %>. <br>
Current Time: <%= Time.now %>.

Section 7.1.3

  1. Displaying the params hash as YAML (see below) looks exactly the same as the debug output in the HTML.
Started GET "/users/1" for 127.0.0.1 at 2018-01-20 23:20:03 -0500
Processing by UsersController#show as HTML
  Parameters: {"id"=>"1"}
  User Load (0.2ms)  SELECT  "users".* FROM "users" WHERE "users"."id" = $1 LIMIT $2  [["id", 1], ["LIMIT", 1]]
Return value is: nil

[1, 10] in /Users/joshualusk/environment/sample_app/app/controllers/users_controller.rb
    1: class UsersController < ApplicationController
    2: 
    3: 	def show
    4: 		@user = User.find(params[:id])
    5: 		debugger
=>  6: 	end
    7: 
    8:   def new
    9:   end
   10: end
(byebug) puts params.to_yaml
--- !ruby/object:ActionController::Parameters
parameters: !ruby/hash:ActiveSupport::HashWithIndifferentAccess
  controller: users
  action: show
  id: '1'
permitted: false
nil

Started GET "/users/new" for 127.0.0.1 at 2018-01-20 23:22:43 -0500
Processing by UsersController#new as HTML
Return value is: nil

[1, 10] in /Users/joshualusk/environment/sample_app/app/controllers/users_controller.rb
    1: class UsersController < ApplicationController
    2: 
    3: 	def show
    4: 		@user = User.find(params[:id])
    5: 	end
    6: 
    7:   def new
    8:   	debugger
=>  9:   end
   10: end
(byebug) @user
nil

Section 7.1.4

  1. The MD5 hash associated with the image for my gravatar email address is a61b37d367dff8110f986469327d1cc4.
  2. The code in listing 7.12 does correctly manipulate the size of the image based on the keyword argument.
  3. The code in listing 7.13 is confirmed to be able to be used in place of the code in listing 7.12.

Section 7.2.1

undefined method `nome' for #<User:0x00007f82d2cf2220>
Did you mean?  name
  1. foobar would be a bad choice for the block variable (currently f) because while f can me mapped to form as a good shorthand variable, foobar is simply a placeholder word that in no way relates to form.

Section 7.2.2

  1. Learn Enough HTML to be Dangerous does not include a server-side component that, in most simple examples, would be required to demonstrate the function of a form tag.

Section 7.3.2

  1. Debug information (from /signup?admin=1 path) displayed below:
--- !ruby/object:ActionController::Parameters
parameters: !ruby/hash:ActiveSupport::HashWithIndifferentAccess
  admin: '1'
  controller: users
  action: new
permitted: false

Section 7.3.3

  1. Chaing the minum password length to 5 updates the error message to read: Password is too short (minimum is 5 characters).
  2. We've pointed the signup route to users#new, but the call to render the new view from the create action results in the path being /users (see Table 7.1).

Section 7.3.4

test "invalid signup information" do
  get signup_path
  assert_no_difference 'User.count' do
  post users_path, params: { user: { name: "",
                                     email: "user@invalid",
                                     password:              "foo",
                                     password_confirmation: "bar" } }
  end
  assert_template 'users/new'
  assert_select 'div#error_explanation'
  assert_select 'div.alert.alert-danger'
  assert_select "li", "Name can't be blank"
  assert_select "li", "Email is invalid"
  assert_select "li", "Password confirmation doesn't match Password"
  min_validation = User.validators_on(:password).find do |v|
    v.options.key?(:minimum)
  end
  min_length = min_validation.options[:minimum]
  assert_select "li", "Password is too short (minimum is #{min_length} characters)"
end
  1. The tests are still green because pointing post /signup to users#create just add another way to navigate to that route, it does not invalidate the use of post /users as a means to trigger the users#create action.
  2. The tests are still green aftering modifying the new.html.erb users view to match Listing 7.2.6.
  3. Adding assert_select 'form[action="/signup"]' as the second assertion in the users_signup integration test helps verify that the sign up form is POSTing to the /signup route, not the /users route.

Section 7.4.1

>> user = User.find(2) # User created on form submission (2nd overall user)
  User Load (0.5ms)  SELECT  "users".* FROM "users" WHERE "users"."id" = $1 LIMIT $2  [["id", 2], ["LIMIT", 1]]
=> #<User id: 2, name: "Josh Lusk", email: "jlusk@example.com", created_at: "2018-01-21 21:06:43", updated_at: "2018-01-21 21:06:43", password_digest: "$2a$10$7jQSCRZ4z8h0eBRnqWYk5.8r4ZFzUKuYvFylU/gxCVt...">
>> user.attributes                                                         
=> {"id"=>2, "name"=>"Josh Lusk", "email"=>"jlusk@example.com", "created_at"=>Sun, 21 Jan 2018 21:06:43 UTC +00:00, "updated_at"=>Sun, 21 Jan 2018 21:06:43 UTC +00:00, "password_digest"=>"$2a$10$7jQSCRZ4z8h0eBRnqWYk5.8r4ZFzUKuYvFylU/gxCVt0ypb6DRime"}
  1. Verified that by updating Listing 7.28 and submitting a valid user that redirect_to user_url(@user) has the same effect as redirect_to @user.

Section 7.4.2

>> "#{:success}"
=> "success"
  1. The section of the flash iteration that sets the class names for the div could be rewritten as follows:
<div class="<%= "alert alert-#{message_type}" %>">

Section 7.4.3

  1. Verified the user was successfully created as in Listing 7.32.
  2. Verified that the Gravatar correctly appear for a new user created with my personal email address.

Section 7.4.4

  1. The line assert_not flash.empty? was added to the bottom of the signup validity test.
  2. All tests still pass after implementing the change in Listing 7.35.
  3. The tests do fail when the redirect_to line in commented out of the User controller's create method (action).
  4. If @user.save is returning false, most likely the validations are catching incorrect user information that is trying to be saved (triggered when User.count is not one more that it was before).

Section 7.5.3

  1. The SSL lock and https appear in next to the URL in my heroku app.
  2. My gravatar does appear correctly on the production site.

Chapter 8

Section 8.1.1

  1. GET login_path routes to the Sessions Controller's show action and POST login_path routes to the Sessions Controller's 'create` action.
$ rails routes | grep 'users#'
   signup GET    /signup(.:format)         users#new
          POST   /signup(.:format)         users#create
    users GET    /users(.:format)          users#index
          POST   /users(.:format)          users#create
 new_user GET    /users/new(.:format)      users#new
edit_user GET    /users/:id/edit(.:format) users#edit
     user GET    /users/:id(.:format)      users#show
          PATCH  /users/:id(.:format)      users#update
          PUT    /users/:id(.:format)      users#update
          DELETE /users/:id(.:format)      users#destroy
$ rails routes | grep 'sessions#'
    login GET    /login(.:format)          sessions#new
          POST   /login(.:format)          sessions#create
   logout DELETE /logout(.:format)         sessions#destroy
$ rails routes | grep 'users#' | wc -l
      10
$ rails routes | grep 'sessions#' | wc -l
       3

Section 8.1.2

  1. Because we addded the key :url to the form_for's hash with the value login_path, the path the URL will be posting to is /login. in config/routes.rb, this path is routed to go to the create action in the sessions controller.

Section 8.1.3

>> user = nil
=> nil
>> !!(user && user.authenticate('foobar'))
=> false
>> user = User.first
  User Load (0.7ms)  SELECT  "users".* FROM "users" ORDER BY "users"."id" ASC LIMIT $1  [["LIMIT", 1]]
=> #<User id: 6, name: "Josh H. Lusk", email: "jlusk@example.com", created_at: "2018-01-17 20:30:34", updated_at: "2018-01-17 20:39:54", password_digest: "$2a$10$PzRIAXrzLt7r22udGGJIAefVk7I.6VMXnuWc62mX2Th...">
>> !!(user && user.authenticate('foobaz'))
=> false
>> !!(user && user.authenticate('foobar'))
=> true

Section 8.1.4

  1. Verified that the flash message disappears when you click on a second page, away from the login view.

Section 8.2.1

  1. Found using Edit My Cookie Chrome Extension: session token
  2. 22/01/2019 4:24PM is the expire time on the session token

Section 8.2.2

>> User.find_by(id: 1000)
  User Load (0.4ms)  SELECT  "users".* FROM "users" WHERE "users"."id" = $1 LIMIT $2  [["id", 1000], ["LIMIT", 1]]
=> nil
  1. Specifically note that no SQL is executed on the last ||= used in conjunction with @current_user:
>> session = {}
=> {}
>> session[:user_id] = nil                              
=> nil
>> @current_user ||= User.find_by(id: session[:user_id])
  User Load (0.4ms)  SELECT  "users".* FROM "users" WHERE "users"."id" IS NULL LIMIT $1  [["LIMIT", 1]]
=> nil
>> session[:user_id] = User.first.id                    
  User Load (0.3ms)  SELECT  "users".* FROM "users" ORDER BY "users"."id" ASC LIMIT $1  [["LIMIT", 1]]
=> 1
>> @current_user ||= User.find_by(id: session[:user_id])
  User Load (0.5ms)  SELECT  "users".* FROM "users" WHERE "users"."id" = $1 LIMIT $2  [["id", 1], ["LIMIT", 1]]
=> #<User id: 1, name: "Rails Tutorial", email: "example@railstutorial.org", created_at: "2018-01-21 21:24:43", updated_at: "2018-01-21 21:24:43", password_digest: "$2a$10$pYeW./EatWhQgNsFlkE1nOIlUmjLPu9IjBLxQAYfjce...">
>> @current_user ||= User.find_by(id: session[:user_id])
=> #<User id: 1, name: "Rails Tutorial", email: "example@railstutorial.org", created_at: "2018-01-21 21:24:43", updated_at: "2018-01-21 21:24:43", password_digest: "$2a$10$pYeW./EatWhQgNsFlkE1nOIlUmjLPu9IjBLxQAYfjce...">

Section 8.2.3

delete session 2. delete session on quit

Section 8.2.4

  1. Removing the ! from the line !current_user.nil? (within the logged_in? method) does cause the tests in test/integration/users_login_test.rb to fail.
  2. The tests again path when the ! is reinstated.

Section 8.2.5

  1. The test suite become red if you comment out the log_in line in Listing 8.25.
  2. The test suite is confirmed to toggle between red and green based on whether or not the log_in line in Listing 8.24 is commented out or not.

Section 8.3

  1. Verified that the logout link works as expected. Once the redirect happens, the Account drop-down is replaced by the Log in link, which is what gets asserted in the last three lines of the test.
  2. The session is correctly removed after logging out.

Chapter 9

>> user = User.first
  User Load (0.5ms)  SELECT  "users".* FROM "users" ORDER BY "users"."id" ASC LIMIT $1  [["LIMIT", 1]]
=> #<User id: 1, name: "Rails Tutorial", email: "example@railstutorial.org", created_at: "2018-01-21 21:24:43", updated_at: "2018-01-21 21:24:43", password_digest: "$2a$10$pYeW./EatWhQgNsFlkE1nOIlUmjLPu9IjBLxQAYfjce...", remember_digest: nil>
>> user.remember
   (0.3ms)  BEGIN
  SQL (51.2ms)  UPDATE "users" SET "updated_at" = $1, "remember_digest" = $2 WHERE "users"."id" = $3  [["updated_at", "2018-01-29 04:39:23.382813"], ["remember_digest", "$2a$10$WautEzRlvGWz2WyiRA6ukOkO5ddMAJt4Kr6zblyA.veO8re/LvctW"], ["id", 1]]
   (0.6ms)  COMMIT
=> true
>> user.remember_token
=> "iNlGdGeybz9yzt90jLPONA"
>> user.remember_digest
=> "$2a$10$WautEzRlvGWz2WyiRA6ukOkO5ddMAJt4Kr6zblyA.veO8re/LvctW"
  1. Both methods (outlined in Listing 9.4 and Listing 9.5 work correctly.

Section 9.1.2

  1. token and user id
>> user = User.first
  User Load (0.5ms)  SELECT  "users".* FROM "users" ORDER BY "users"."id" ASC LIMIT $1  [["LIMIT", 1]]
=> #<User id: 1, name: "Rails Tutorial", email: "example@railstutorial.org", created_at: "2018-01-21 21:24:43", updated_at: "2018-01-29 04:55:49", password_digest: "$2a$10$pYeW./EatWhQgNsFlkE1nOIlUmjLPu9IjBLxQAYfjce...", remember_digest: "$2a$10$2pVtFKovRYJDn5QrWXh6jeMXfwuCxrGq40pt7S/ckeE...">
>> user.authenticated?('notokenyet')
=> false
>> user.remember
   (0.3ms)  BEGIN
  SQL (0.6ms)  UPDATE "users" SET "updated_at" = $1, "remember_digest" = $2 WHERE "users"."id" = $3  [["updated_at", "2018-01-29 04:59:40.255900"], ["remember_digest", "$2a$10$9jvDJhDMEG2mh9OfLx5E2O2g8JQSialxY1YYah8GJdqxeHOcfs1.q"], ["id", 1]]
   (0.8ms)  COMMIT
=> true
>> user.authenticated?(user.remember_token)
=> true
>>

Section 9.1.3

  1. remember cookies removed

Section 9.1.4

  1. double logout error
  2. double browser logout error
  3. Uncommenting the fixes does change the test suite from red to green:
Finished in 0.54743s
24 tests, 68 assertions, 0 failures, 0 errors, 0 skips
...
Finished in 0.578573s, 41.4814 runs/s, 117.5305 assertions/s.
24 runs, 68 assertions, 0 failures, 0 errors, 0 skips

Section 9.2

  1. The checkbox is having its intended effect; checking it adds both a remember_token and a user_id cookie to the browser, and not checking it adds neither.
>> 1 == 2 ? 'no way' : 'phew!'
=> "phew!"
>> 2 == 2 ? 'that\'s better' : 'not gonna happen'
=> "that's better"

Section 9.3.2

  1. The test fails with the authenticated? part of the expression removed:
Failure:
SessionsHelperTest#test_current_user_returns_nil_when_remember_digest_is_wrong [/Users/joshualusk/environment/sample_app/test/helpers/sessions_helper_test.rb:17]:
Expected #<User id: 208889123, name: "Foo Bar", email: "foo@bar.com", created_at: "2018-02-03 15:42:48", updated_at: "2018-02-03 15:42:48", password_digest: "$2a$04$vpjPuDJWYiardb28TO1/yet4Tx6XudLZ.rjnrhDAEDK...", remember_digest: "$2a$04$pMwZWHcZ8RtD7o5M13M6ielnjUKyCf0P/.GvKlRqVK5..."> to be nil.
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