no route matches service-worker.js

Question

I generated rails application and I got this message out of box. I don't know what service-worker.js is but I assume it can be bundled with some default gem?

Started GET "/service-worker.js" for 127.0.0.1 at 2015-07-21 19:48:33 +0200

ActionController::RoutingError (No route matches [GET] "/service-worker.js"):
  actionpack (4.2.3) lib/action_dispatch/middleware/debug_exceptions.rb:21:in `call'
  web-console (2.2.1) lib/web_console/middleware.rb:39:in `call'
  actionpack (4.2.3) lib/action_dispatch/middleware/show_exceptions.rb:30:in `call'
  railties (4.2.3) lib/rails/rack/logger.rb:38:in `call_app'
  railties (4.2.3) lib/rails/rack/logger.rb:20:in `block in call'
  activesupport (4.2.3) lib/active_support/tagged_logging.rb:68:in `block in tagged'
  activesupport (4.2.3) lib/active_support/tagged_logging.rb:26:in `tagged'
  activesupport (4.2.3) lib/active_support/tagged_logging.rb:68:in `tagged'
  railties (4.2.3) lib/rails/rack/logger.rb:20:in `call'
  actionpack (4.2.3) lib/action_dispatch/middleware/request_id.rb:21:in `call'
  rack (1.6.4) lib/rack/methodoverride.rb:22:in `call'
  rack (1.6.4) lib/rack/runtime.rb:18:in `call'
  activesupport (4.2.3) lib/active_support/cache/strategy/local_cache_middleware.rb:28:in `call'
  rack (1.6.4) lib/rack/lock.rb:17:in `call'
  actionpack (4.2.3) lib/action_dispatch/middleware/static.rb:116:in `call'
  rack (1.6.4) lib/rack/sendfile.rb:113:in `call'
  railties (4.2.3) lib/rails/engine.rb:518:in `call'
  railties (4.2.3) lib/rails/application.rb:165:in `call'
  rack (1.6.4) lib/rack/lock.rb:17:in `call'
  rack (1.6.4) lib/rack/content_length.rb:15:in `call'
  rack (1.6.4) lib/rack/handler/webrick.rb:88:in `service'
  /home/emkacf/.rvm/rubies/ruby-2.2.1/lib/ruby/2.2.0/webrick/httpserver.rb:138:in `service'
  /home/emkacf/.rvm/rubies/ruby-2.2.1/lib/ruby/2.2.0/webrick/httpserver.rb:94:in `run'
  /home/emkacf/.rvm/rubies/ruby-2.2.1/lib/ruby/2.2.0/webrick/server.rb:294:in `block in start_thread'

Answer 1

I assume that is from another application which uses webworkers. If you are using Firefox, go to menu > web developer > service workers and unregister webworker from there (That's the one way to do it). The other application will register it again if needed.

Answer 2

This coming from client-side so it's from a service-worker that has been registered in the browser.

Open DevTools and run navigator.serviceWorker.getRegistration().then(r => r.unregister()) in your console to disable it.