Guard, red green refactor with Rubocop

Guardfile

group :red_green_refactor, halt_on_fail: true do
  guard :rspec, failed_mode: :keep, all_after_pass: true do
    watch('spec/spec_helper.rb')                        { "spec" }
    watch('spec/factories/factories.rb')                { "spec" }
    watch('config/routes.rb')                           { "spec/routing" }
    watch('app/controllers/application_controller.rb')  { "spec/controllers" }
    watch(%r{^spec/.+_spec\.rb$})
    watch(%r{^app/(.+)\.rb$})                           { |m| "spec/#{m[1]}_spec.rb" }
    watch(%r{^lib/(.+)\.rb$})                           { |m| "spec/lib/#{m[1]}_spec.rb" }
    watch(%r{^app/controllers/(.+)_(controller)\.rb$})  { |m| ["spec/routing/#{m[1]}_routing_spec.rb", "spec/#{m[2]}s/#{m[1]}_#{m[2]}_spec.rb", "spec/acceptance/#{m[1]}_spec.rb"] }
  end

  guard :rubocop, all_on_start: false, cli: ['--format', 'simple', '--rails'] do
    watch(%r{.+\.rb$})
    watch(%r{(?:.+/)?\.rubocop\.yml$}) { |m| File.dirname(m[0]) }
  end
end

Rakefile

if %w(development test).include?(Rails.env)
  require 'rubocop/rake_task'
  Rubocop::RakeTask.new

  task(:default).clear
  task default: [:spec, :rubocop]
end