Double Render Error with simple controller - ruby-on-rails

Question

I'm getting a weird error in my api rails app:
AbstractController::DoubleRenderError in Api::V1::AdsController#restaurant
Render and/or redirect were called multiple times in this action. Please note that you may only call render OR redirect, and at most once per action. Also note that neither redirect nor render terminate execution of the action, so if you want to exit an action after redirecting, you need to do something like "redirect_to(...) and return".
I found this page https://api.rubyonrails.org/classes/ActionController/Base.html about double rendering, but I don't really get what they mean and how it applies to my situation.
I have this in my controller:
class Api::V1::AdsController < Api::V1::BaseController
before_action :set_ad, only: [ :show ]
def index
#ads = policy_scope(Subcategory.find_by(nombre: "Restaurantes").ads)
end
def restaurant
#restaurants = policy_scope(Subcategory.find_by(nombre: "Restaurantes").ads)
end
def show
end
private
def set_ad
#ad = Ad.find(params[:id])
authorize #ad
end
end
And this in my routes:
Rails.application.routes.draw do
devise_for :users
namespace :api, defaults: { format: :json } do
namespace :v1 do
resources :ads, only: [ :index, :show ] do
collection do
get 'restaurant', to: 'ads#restaurant'
end
end
end
end
root to: 'pages#home'
# For details on the DSL available within this file, see http://guides.rubyonrails.org/routing.html
end
And I have 3 views:
index.json.jbuilder:
json.array! #ads do |ad|
json.extract! ad,
:id,
:empresa,
:direccion_principal,
:tel,
:email_principal,
:web,
:facebook,
:instagram,
:twitter,
:isla
end
restaurant.json.jbuilder = the same as index
show.json.jbuilder:
json.extract! #ad, :id, :empresa, :direccion_principal
Can someone see the problem here?
EDIT:
AdPolicy:
class AdPolicy < ApplicationPolicy
class Scope < Scope
def resolve
scope.all
end
end
def show?
true
end
end
Base Controller:
class Api::V1::BaseController < ActionController::API
include Pundit
after_action :verify_authorized, except: :index
after_action :verify_policy_scoped, only: :index
rescue_from StandardError, with: :internal_server_error
rescue_from Pundit::NotAuthorizedError, with: :user_not_authorized
rescue_from ActiveRecord::RecordNotFound, with: :not_found
private
def user_not_authorized(exception)
render json: {
error: "Unauthorized #{exception.policy.class.to_s.underscore.camelize}.#{exception.query}"
}, status: :unauthorized
end
def not_found(exception)
render json: { error: exception.message }, status: :not_found
end
def internal_server_error(exception)
if Rails.env.development?
response = { type: exception.class.to_s, message: exception.message, backtrace: exception.backtrace }
else
response = { error: "Internal Server Error" }
end
render json: response, status: :internal_server_error
end
end

Answer 1

I found the answer to my own question. It had to do with the BaseController. I forgot to add :restaurant to the after_action :verify_authorized and verify_policy_scoped. With the BaseController below it works now.
class Api::V1::BaseController < ActionController::API
include Pundit
after_action :verify_authorized, except: [:index, :restaurant]
after_action :verify_policy_scoped, only: [:index, :restaurant, :beach_restaurant, :cafe]
rescue_from StandardError, with: :internal_server_error
rescue_from Pundit::NotAuthorizedError, with: :user_not_authorized
rescue_from ActiveRecord::RecordNotFound, with: :not_found
private
def user_not_authorized(exception)
render json: {
error: "Unauthorized #{exception.policy.class.to_s.underscore.camelize}.#{exception.query}"
}, status: :unauthorized
end
def not_found(exception)
render json: { error: exception.message }, status: :not_found
end
def internal_server_error(exception)
if Rails.env.development?
response = { type: exception.class.to_s, message: exception.message, backtrace: exception.backtrace }
else
response = { error: "Internal Server Error" }
end
render json: response, status: :internal_server_error
end
end