Can't believe this one took me so long to figure out.

Guardfile

guard 'spork', :rspec_env => { 'RAILS_ENV' => 'test' } do
  watch('Gemfile.lock')
  watch('spec/spec_helper.rb')
  watch('config/application.rb')
  watch('config/environment.rb')
  watch(%r{^config/environments/.+\.rb$})
  watch(%r{^config/initializers/.+\.rb$})
  watch(%r{^spec/support/.+\.rb$})
  watch(%r{^spec/factories/.+\.rb$})
  # watch(%r{^spec/factories/.+\.rb$}) # Uncomment when you have a large amount of factories
  # watch(%r{^spec/fabricators/.+\.rb$}) # Uncomment when you have a large amount of fabricators
end

guard 'rspec', version: 2, cli: '--drb --color --format documentation', all_on_start: false, all_after_pass: false do
  watch(%r{^lib/(.+)\.rb$})                           { |m| "spec/lib/#{m[1]}_spec.rb" }
  watch(%r{^lib/decorators/(.+)_decorator\.rb$})      { |m| "spec/models/#{m[1]}_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$})  { |m| ["spec/#{m[2]}s/#{m[1]}_#{m[2]}_spec.rb" ] }
  watch('spec/spec_helper.rb')
  watch(%r{^spec/support/.+\.rb$})
  watch(%r{^spec/((?!requests).)+_spec\.rb$})
  watch('app/controllers/application_controller.rb')  { "spec/controllers" }
  watch(%r{^spec/fabricators/(.+)_fabricator\.rb$})   { |m| "spec/models/#{m[2]}_spec.rb" }
  watch(%r{^spec/factories/(.+)_factory\.rb$})        { |m| "spec/models/#{m[2]}_spec.rb" }
end

guard 'rspec', version: 2, cli: '--color --format documentation', all_on_start: false, all_after_pass: false do
  # spork and capybara do not get along. watch capybara specs in a non-drb guard.
  watch(%r{^spec/(.*requests.*)_spec\.rb$})
  watch(%r{^app/controllers/(.+)_(controller)\.rb$})  { |m| ["spec/requests/#{m[1]}_page_spec.rb" ] }
end