Setup Rspec

Installation

When creating new apps, we run rails new with the -T flag to avoid creating any Minitest files. If you have an existing Rails app and forgot to pass that flag, you can always remove /test manually to avoid having an unused folder in your project.

Use rspec-rails to install RSpec in a Rails app, as it configures many of the things you need for Rails testing out of the box. The plain ol' rspec gem is used for testing non-Rails programs.

Be sure to add the gem to both the :development and :test groups in your Gemfile. It needs to be in :development to expose Rails generators and rake tasks at the command line.

group :development, :test do
  gem 'rspec-rails', '~> 3.0'
end

Bundle install:

bundle install

Generate RSpec files:

rails generate rspec:install

This creates the following files:

• .rspec

  Configures the default flags that are passed when you run rspec. The line --require spec_helper is notable, as it will automatically require the spec helper file for every test you run.

• spec/spec_helper.rb

  Further customizes how RSpec behaves. Because this is loaded in every test, you can guarantee it will be run when you run a test in isolation. Tests run in isolation should run near instantaneously, so be careful adding any dependencies to this file that won't be needed by every test. If you have configurations that need to be loaded for a subset of your test suite, consider making a separate helper file and load it only in those files.

  At the bottom of this file is a comment block the RSpec maintainers suggest we enable for a better experience. We agree with most of the customizations. I've uncommented them, then commented out a few specific settings to reduce some noise in test output.

• spec/rails_helper.rb

  A specialized helper file that loads Rails and its dependencies. Any file that depends on Rails will need to require this file explicitly.

The generated spec helpers come with plenty of comments describing what each configuration does. I encourage you to read those comments to get an idea of how you can customize RSpec to suit your needs. I won't cover them as they tend to change with each RSpec version.