json

if valid_user
  render status: :ok, json: { user_id: valid_user.id}
else
  render status: :unauthorized, json: {}
end

def destroy
  @post.destroy!
  head :no_content
end

Views rendering convention

By default, controllers in Rails automatically render views with names that correspond to valid routes.(NOTE: according to valid routes not action method)

class ThingsController < ApplicationController
end

# routes.rb
get '/ten_best_things_in_your_life' => 'things#ten_best_things_in_your_life', as: :ten_best_things_in_your_life

# /views/things/ten_best_things_in_your_life.html.slim

Visiting /ten_best_things_in_your_life will render ten_best_things_in_your_life page correspondingly due to Rails's convention

Reference

• Layouts and Rendering in Rails
• 403 Forbidden vs 401 Unauthorized HTTP responses
• Understanding 403 Forbidden
• W3 spec
• 400 BAD request HTTP error code meaning?
• Rendering head :ok vs head :no_content. Any good practices?
• 2.1 Rendering by Default: Convention Over Configuration in Action