Estou tentando descobrir o que há de errado com este código. Ou seja, ele não pode encontrar o método 'stub_model'. Tentei procurar solução para isso, mas em todos os lugares que olho meus arquivos parece ser bom. Por favor, dê uma olhada nele, talvez eu não consiga ver um erro simples. Muito obrigado :) Modelo de livro é criado em db.

Minha especificação de visualização (spec / view / books_spec.rb) tem a seguinte aparência:

require 'rails_helper'

describe 'books/new' do

  it 'displays the book form' do
    book = stub_model(Book)
    assign(:book, book)
    render
    expect(rendered).to have_selector("form label[for *= 'Title']")
    expect(rendered).to have_selector("form label[for *= 'Author']")
    expect(rendered).to have_selector("form label[for *= 'Cover Photo']")
    expect(rendered).to have_button "Add Book"
  end
end

e o erro é o seguinte:

1) books/new displays the book form
     Failure/Error: book = stub_model(Book)
     NoMethodError:
       undefined method `stub_model' for #<RSpec::ExampleGroups::BooksNew:0x00000103e61870>
     # ./spec/views/books_spec.rb:6:in `block (2 levels) in <top (required)>'

Meu rails_helper.rb se parece com:

# This file is copied to spec/ when you run 'rails generate rspec:install'
ENV["RAILS_ENV"] ||= 'test'
require 'spec_helper'
require File.expand_path("../../config/environment", __FILE__)
require 'rspec/rails'

# Requires supporting ruby files with custom matchers and macros, etc, in
# spec/support/ and its subdirectories. Files matching `spec/**/*_spec.rb` are
# run as spec files by default. This means that files in spec/support that end
# in _spec.rb will both be required and run as specs, causing the specs to be
# run twice. It is recommended that you do not name files matching this glob to
# end with _spec.rb. You can configure this pattern with with the --pattern
# option on the command line or in ~/.rspec, .rspec or `.rspec-local`.
Dir[Rails.root.join("spec/support/**/*.rb")].each { |f| require f }

# Checks for pending migrations before tests are run.
# If you are not using ActiveRecord, you can remove this line.
ActiveRecord::Migration.maintain_test_schema!

RSpec.configure do |config|
  # Remove this line if you're not using ActiveRecord or ActiveRecord fixtures
  config.fixture_path = "#{::Rails.root}/spec/fixtures"

  # If you're not using ActiveRecord, or you'd prefer not to run each of your
  # examples within a transaction, remove the following line or assign false
  # instead of true.
  config.use_transactional_fixtures = true

  # RSpec Rails can automatically mix in different behaviours to your tests
  # based on their file location, for example enabling you to call `get` and
  # `post` in specs under `spec/controllers`.
  #
  # You can disable this behaviour by removing the line below, and instead
  # explicitly tag your specs with their type, e.g.:
  #
  #     RSpec.describe UsersController, :type => :controller do
  #       # ...
  #     end
  #
  # The different available types are documented in the features, such as in
  # https://relishapp.com/rspec/rspec-rails/docs
  config.infer_spec_type_from_file_location!
end

e meu Gemfile.rb:

source 'https://rubygems.org'


# Bundle edge Rails instead: gem 'rails', github: 'rails/rails'
gem 'rails', '4.1.2.rc1'
# Use postgresql as the database for Active Record
gem 'pg'
# Use SCSS for stylesheets
gem 'sass-rails', '~> 4.0.3'
# Use Uglifier as compressor for JavaScript assets
gem 'uglifier', '>= 1.3.0'
# Use CoffeeScript for .js.coffee assets and views
gem 'coffee-rails', '~> 4.0.0'
# See https://github.com/sstephenson/execjs#readme for more supported runtimes
# gem 'therubyracer',  platforms: :ruby

# Use jquery as the JavaScript library
gem 'jquery-rails'
# Turbolinks makes following links in your web application faster. Read more: https://github.com/rails/turbolinks
gem 'turbolinks'
# Build JSON APIs with ease. Read more: https://github.com/rails/jbuilder
gem 'jbuilder', '~> 2.0'
# bundle exec rake doc:rails generates the API under doc/api.
gem 'sdoc', '~> 0.4.0',          group: :doc

# Spring speeds up development by keeping your application running in the background. Read more: https://github.com/rails/spring
gem 'spring',        group: :development


group :test do
  gem 'cucumber-rails', :require => false
  gem 'database_cleaner'
end

group :development, :test do
  gem 'rspec-rails'
  gem 'factory_girl_rails'
end
# Use ActiveModel has_secure_password
# gem 'bcrypt', '~> 3.1.7'

# Use unicorn as the app server
# gem 'unicorn'

# Use Capistrano for deployment
# gem 'capistrano-rails', group: :development

# Use debugger
# gem 'debugger', group: [:development, :test]