Rescue ActionController::UnknownFormat from raising an exception

Question

I am trying to make it so that an ActionController::UnknownFormat will not raise an exception report in production. I'm using Rails 4 and thought something like this would do the trick, but it doesn't seem to make a difference:

application.rb

config.action_dispatch.rescue_responses.merge!('ActionController::UnknownFormat' => :not_found)

Answer 1

It looks like this was deprecated in Rails 4 in favor of this rescue_from syntax. So something like this:

application_controller.rb:

  rescue_from ActionController::UnknownFormat, with: :raise_not_found

  def raise_not_found
    render(text: 'Not Found', status: 404)
  end

Answer 2

It should not return status code 404, should return status code 415 i.e unsupported_media_type

rescue_from ActionController::UnknownFormat, with: :raise_not_found

def raise_not_found
  render(text: 'Not Found', status: :unsupported_media_type)
end