Railsチュートリアルの第３章のRSpecの設定時にエラーが発生してしまう。

Question

現在Railsチュートリアル（http://railstutorial.jp/）を使って学習をしているんですが、第３章のテストを実行しようとした際にエラーになってしまって困っています。

3.2.1テスト駆動開発の下記コマンドを実行すると、

$ bundle exec rspec spec/requests/static_pages_spec.rb

下記のエラーが出てしまいます。

/home/hiro/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/activesupport-4.0.5/lib/active_support/dependencies.rb:229:in `require': cannot load such file -- test/unit/assertions (LoadError)
	from /home/hiro/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/activesupport-4.0.5/lib/active_support/dependencies.rb:229:in `block in require'
	from /home/hiro/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/activesupport-4.0.5/lib/active_support/dependencies.rb:214:in `load_dependency'
	from /home/hiro/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/activesupport-4.0.5/lib/active_support/dependencies.rb:229:in `require'
	from /home/hiro/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/rspec-rails-2.13.1/lib/rspec/rails/adapters.rb:3:in `<top (required)>'
	from /home/hiro/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/activesupport-4.0.5/lib/active_support/dependencies.rb:229:in `require'
	from /home/hiro/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/activesupport-4.0.5/lib/active_support/dependencies.rb:229:in `block in require'
	from /home/hiro/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/activesupport-4.0.5/lib/active_support/dependencies.rb:214:in `load_dependency'
	from /home/hiro/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/activesupport-4.0.5/lib/active_support/dependencies.rb:229:in `require'
	from /home/hiro/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/rspec-rails-2.13.1/lib/rspec/rails.rb:11:in `<top (required)>'
	from /home/hiro/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/activesupport-4.0.5/lib/active_support/dependencies.rb:229:in `require'
	from /home/hiro/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/activesupport-4.0.5/lib/active_support/dependencies.rb:229:in `block in require'
	from /home/hiro/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/activesupport-4.0.5/lib/active_support/dependencies.rb:214:in `load_dependency'
	from /home/hiro/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/activesupport-4.0.5/lib/active_support/dependencies.rb:229:in `require'
	from /home/hiro/Documents/rails_projects/sample_app/spec/spec_helper.rb:4:in `<top (required)>'
	from /home/hiro/Documents/rails_projects/sample_app/spec/requests/static_pages_spec.rb:1:in `require'
	from /home/hiro/Documents/rails_projects/sample_app/spec/requests/static_pages_spec.rb:1:in `<top (required)>'
	from /home/hiro/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/rspec-core-2.13.1/lib/rspec/core/configuration.rb:819:in `load'
	from /home/hiro/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/rspec-core-2.13.1/lib/rspec/core/configuration.rb:819:in `block in load_spec_files'
	from /home/hiro/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/rspec-core-2.13.1/lib/rspec/core/configuration.rb:819:in `each'
	from /home/hiro/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/rspec-core-2.13.1/lib/rspec/core/configuration.rb:819:in `load_spec_files'
	from /home/hiro/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/rspec-core-2.13.1/lib/rspec/core/command_line.rb:22:in `run'
	from /home/hiro/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/rspec-core-2.13.1/lib/rspec/core/runner.rb:80:in `run'
	from /home/hiro/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/rspec-core-2.13.1/lib/rspec/core/runner.rb:17:in `block in autorun'

RSpecを指定しているはずなのに、デフォルトのtest::unitが呼ばれてしまってるみたいで、どなたわかる方いらっしゃいますか？

Answer 1

Gemfileに

gem 'test-unit’

を追記すれば解決するかもしれません。
私も同じところでハマリました。

Answer 2

Gemfileに'rspec-rails'は入っていますかね?
記述しただけでなく、bundle install と rspecの設定は完了してますか

bundle install
rails generate rspec:install

正しくrspecが設定されていれば、taskにrspecが追加されていると思うので、確認してみてください。

bundle exec rake -vT
----
rake spec                                 # Run all specs in spec directory (excluding plugin specs)
rake spec:controllers                     # Run the code examples in spec/controllers
rake spec:helpers                         # Run the code examples in spec/helpers
rake spec:lib                             # Run the code examples in spec/lib
rake spec:models                          # Run the code examples in spec/models
rake spec:requests                        # Run the code examples in spec/requests
rake spec:routing                         # Run the code examples in spec/routing
rake spec:views                           # Run the code examples in spec/views