Ignore query parameters if same name already exists as a path parameter

[jgraichen]

When reusing controllers on different paths identically named placeholders might be added. See this example:

  get '/users/:user_id/permissions' => 'permissions#index'
  get '/permissions' => 'permissions#index'

The same controller is used for both actions as the user_id is just an optional filter for the permissions controller. Nevertheless the controller describes it as a param:

class PermissionsController < ApplicationController
  rfc6570_params index: %i[context user_id]
end

This will generate the following URI template for user_permissions:

/users/{user_id}/permissions{?context}{&user_id}

This will insert the User ID twice when expanding:

/users/fd32a10b-e900-4fdb-a4fd-6fe7002fb87c/permissions?user_id=fd32a10b-e900-4fdb-a4fd-6fe7002fb87c{&context}

Proposal

The query parameter user_id might just be skipped while kept for other routes:

user_permissions => /users/{user_id}/permissions{?context}
permissions => /permissions{?context}{&user_id}