Rails Test errors, while learning rails tutorial - ruby-on-rails

Question

I am currently learning Rails Tutorial. I have error messages after rails test, TDD. There are more messages, but first of all i want to debug these. Even though rails test is not working well, application itself is working without problem as of now.
I took a look this sample codes.
https://github.com/yasslab/sample_apps
Error messages
11) Error:
StaticPagesControllerTest#test_should_get_about:
NameError: undefined local variable or method `static_pages_about_url' for #<StaticPagesControllerTest:0x00000006f89228>
StaticPagesControllerTest#test_should_get_home:NameError: undefined local variable or method `static_pages_home_url' for #<StaticPagesControllerTest:0x00000006f964a0>
test/controllers/static_pages_controller_test.rb:7:in `block in <class:StaticPagesControllerTest>' 13) Error:
StaticPagesControllerTest#test_should_get_contact:NameError: undefined local variable or method `static_pages_contact_url' for #<StaticPagesControllerTest:0x0000000623d600>
test/controllers/static_pages_controller_test.rb:27:in `block in <class:StaticPagesControllerTest>' 14) Error:StaticPagesControllerTest#test_should_get_help:NameError: undefined local variable or method `static_pages_help_url' for #<StaticPagesControllerTest:0x00000006f9d6d8> test/controllers/static_pages_controller_test.rb:13:in `block in <class:StaticPagesControllerTest>'
static_pages_controller.rb
class StaticPagesController < ApplicationController
def home
end
def help
end
def about
end
def contact
end
end
static_pages_controller_test.rb
class StaticPagesControllerTest < ActionController::TestCase
test "should get home" do
get static_pages_home_url
assert_response :success
assert_select "title", "Ruby on Rails Tutorial Sample App"
end
test "should get help" do
get static_pages_help_url
assert_response :success
assert_select "title", "Help | Ruby on Rails Tutorial Sample App"
end
test "should get about" do
get static_pages_about_url
assert_response :success
assert_select "title", "About | Ruby on Rails Tutorial Sample App"
end
test "should get contact" do
get static_pages_contact_url
assert_response :success
assert_select "title", "Contact | Ruby on Rails Tutorial Sample App"
end
end
routes.rb
Rails.application.routes.draw do
get 'sessions/new'
root 'static_pages#home'
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
I want to make these errors into assertions.
Could you kindly help me?