Resources without a controller name creates a valid url/path

By definition, you cannot use resources without a controller name unless it’s under a namespace. This creates a valid helper and URL leading nowhere, e.g:

# config/routes.rb
Rails.application.routes.draw do
  namespace :api do

Which makes the mapper code use “api/” as the controller;

$ rails routes
    Prefix Verb   URI Pattern        Controller#Action
api__index GET    /api(.:format)     api/#index
           POST   /api(.:format)     api/#create
       api GET    /api/:id(.:format) api/#show
           PATCH  /api/:id(.:format) api/#update
           PUT    /api/:id(.:format) api/#update
           DELETE /api/:id(.:format) api/#destroy

Opening this topic to understand if this is a/the expected case or if it might just lead to uncertain bugs and/or confusions.

That is a bug. We should not accept resources without any argument.