Guardfile

require 'active_support/inflector'

guard 'rspec', :version => 2 do
  # ...
  # entries auto-generated after running "guard init rspec"
  # ...
  watch(%r{^spec/factories/(.+)\.rb$}) do |m|
    %W[
      spec/models/#{m[1].singularize}_spec.rb
      spec/controllers/#{m[1]}_controller_spec.rb
      spec/requests/#{m[1]}_spec.rb
    ]
  end
end