Guard and Spork Setup for Rails 3.x

guard_and_spork_for_rails_3.rb

# Instructions
#   1. Add the following to the indicated files
#   2. $ bundle
#   3. $ guard
#   4. Specs should run automatically on file save
#
# Note that some finagling of gem versions might be necessary depending on the
# project.

# .rspec
--drb

# Gemfile
group :test do
  gem "childprocess"
  gem "rb-fsevent", require: false
  gem "guard", '>=2.1.0'
  gem "guard-rspec"
  gem "guard-spork"
  gem "spork", "~> 1.0.0rc4"
end

# spec/spec_helper.rb
require 'spork'

Spork.prefork do
  # Loading more in this block will cause your tests to run faster. However,
  # if you change any configuration or code from libraries loaded here, you'll
  # need to restart spork for it take effect.

  # Routes reload
  require 'rails/application'
  Spork.trap_method(Rails::Application::RoutesReloader, :reload!)

  # Existing spec_helper here
end

# Guardfile
guard 'spork', rspec_env: { 'RAILS_ENV' => 'test' } do
  watch('config/application.rb')
  watch('config/environment.rb')
  watch(%r{^config/environments/.+\.rb$})
  watch(%r{^config/initializers/.+\.rb$})
  watch('Gemfile')
  watch('Gemfile.lock')
  watch('spec/spec_helper.rb')
  watch('spec/support/')
end

guard 'rspec', all_on_start: false, all_after_pass: false, cmd: 'rspec --drb' do
  watch(%r{^spec/.+_spec\.rb$})
  watch(%r{^lib/(.+)\.rb$})     { |m| "spec/lib/#{m[1]}_spec.rb" }
  watch('spec/spec_helper.rb')  { "spec" }

  # Rails example
  watch(%r{^app/(.+)\.rb$})                           { |m| "spec/#{m[1]}_spec.rb" }
  watch(%r{^app/(.*)(\.erb|\.haml)$})                 { |m| "spec/#{m[1]}#{m[2]}_spec.rb" }
  watch(%r{^app/controllers/(.+)_(controller)\.rb$})  { |m| ["spec/routing/#{m[1]}_routing_spec.rb", "spec/#{m[2]}s/#{m[1]}_#{m[2]}_spec.rb", "spec/acceptance/#{m[1]}_spec.rb"] }
  watch(%r{^spec/support/(.+)\.rb$})                  { "spec" }
  watch('config/routes.rb')                           { "spec/routing" }
  watch('app/controllers/application_controller.rb')  { "spec/controllers" }

  # Capybara features specs
  watch(%r{^app/views/(.+)/.*\.(erb|haml)$})          { |m| "spec/features/#{m[1]}_spec.rb" }
end