【RSpec】RSpec実行時にエラー uninitialized constant Shoulda

Question

前提・実現したいこと

RSpec実行時にエラーが起きてしまい、原因が分かりません。RSpecが正しく実行されるようにしたいです。

RSpec教本　　「Everyday Rails - RSpecによるRailsテスト入門」　でRSpecの学習をしている初学者です。

テキストに沿って学習を進めていたはずなのですが、RSpec実行の際に

An error occurred while loading ./スペック名 　　　　　　　　　　　　　　　　　　　　　~中略~　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　 NameError:uninitialized constant Shoulda

というエラーが出るようになってしまいました。

途中までは以下のようなGem　・　Shoulda Matchersを使うようなテストが通っていました。

it { is_expected.to validate_presence_of :email }

ケアレスミスなのかもしれませんが、設定ファイルなどを変更した心当たりもありません。
よろしくお願い致します。

環境

Ruby 2.5.0
Rails 5.1.7
rspec-rails 3.8.3

発生している問題・エラーメッセージ

$ bin/rspec

Running via Spring preloader in process 5952

An error occurred while loading ./spec/controllers/home_controller_spec.rb.
Failure/Error:
  Shoulda::Matchers.configure do |config|
    config.integrate do |with|
      with.test_framework :rspec
      with.library :rails
    end
  end

NameError:
  uninitialized constant Shoulda
# ./spec/rails_helper.rb:64:in `<top (required)>'
# ./spec/controllers/home_controller_spec.rb:1:in `<top (required)>'
# -e:1:in `<main>'

An error occurred while loading ./spec/controllers/notes_controller_spec.rb.
Failure/Error:
  Shoulda::Matchers.configure do |config|
    config.integrate do |with|
      with.test_framework :rspec
      with.library :rails
    end
  end

NameError:
  uninitialized constant Shoulda
# ./spec/rails_helper.rb:64:in `<top (required)>'
# ./spec/controllers/notes_controller_spec.rb:1:in `<top (required)>'
# -e:1:in `<main>'

[中略]

Finished in 0.00037 seconds (files took 0.39113 seconds to load)
0 examples, 0 failures, 1 error occurred outside of examples

該当のソースコード

source 'https://rubygems.org'

git_source(:github) do |repo_name|
  repo_name = "#{repo_name}/#{repo_name}" unless repo_name.include?("/")
  "https://github.com/#{repo_name}.git"
end

gem 'rails', '~> 5.1.1'
gem 'sqlite3'
gem 'puma', '~> 3.7'
gem 'sass-rails', '~> 5.0'
gem 'uglifier', '>= 1.3.0'
gem 'coffee-rails', '~> 4.2'
gem 'turbolinks', '~> 5'
gem 'jbuilder', '~> 2.5'

group :development, :test do
  gem 'rspec-rails', '~> 3.6.0'
  gem "factory_bot_rails", "~> 4.10.0"
  gem 'byebug', platforms: [:mri, :mingw, :x64_mingw]
  gem 'capybara', '~> 3.25.0'
  gem 'webdrivers'
  gem 'launchy',  '~> 2.4.3'
  gem 'selenium-webdriver'
  gem 'shoulda-matchers',
    git: 'https://github.com/thoughtbot/shoulda-matchers.git',
    branch: 'rails-5'
end

group :development do
  gem 'web-console', '>= 3.3.0'
  gem 'listen', '>= 3.0.5', '< 3.2'
  gem 'spring'
  gem 'spring-watcher-listen', '~> 2.0.0'
  gem 'faker', require: false # for sample data in development
  gem 'spring-commands-rspec'
end

gem 'tzinfo-data', platforms: [:mingw, :mswin, :x64_mingw, :jruby]

gem 'bootstrap-sass'
gem 'jquery-rails'
gem 'devise'
gem 'paperclip'
gem 'geocoder'

spec/rails_helper.rb

# This file is copied to spec/ when you run 'rails generate rspec:install'
require 'spec_helper'
ENV['RAILS_ENV'] ||= 'test'
require File.expand_path('../../config/environment', __FILE__)
# Prevent database truncation if the environment is production
abort("The Rails environment is running in production mode!") if Rails.env.production?
require 'rspec/rails'
# Add additional requires below this line. Rails is not loaded until this point!
require 'capybara/rspec'

# 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 the --pattern
# option on the command line or in ~/.rspec, .rspec or `.rspec-local`.
#
# The following line is provided for convenience purposes. It has the downside
# of increasing the boot-up time by auto-requiring all files in the support
# directory. Alternatively, in the individual `*_spec.rb` files, manually
# require only the support files necessary.
#
Dir[Rails.root.join('spec/support/**/*.rb')].each { |f| require f }

# Checks for pending migration and applies them 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!

  # Filter lines from Rails gems in backtraces.
  config.filter_rails_from_backtrace!
  # arbitrary gems may also be filtered via:
  # config.filter_gems_from_backtrace("gem name")
  # コントローラスペックで、Deviseのテストヘルパーを使用する
  config.include Devise::Test::ControllerHelpers, type: :controller
  config.include RequestSpecHelper, type: :request
  config.include Devise::Test::IntegrationHelpers, type: :feature
end

Shoulda::Matchers.configure do |config|
  config.integrate do |with|
    with.test_framework :rspec
    with.library :rails
  end
end

Answer 1

自己解決しました。

最後まで原因が分かりませんでしたが、Githubにアップされている大元のソースコードをrails_heleprにコピペした所、テストが通りました。

この作業自体は質問した当日にも行ったのですが…。