Create use case for deleting questions

app/controllers/ajax/question_controller.rb

@@ -3,25 +3,16 @@
 require "errors"
 require "use_case/question/create"
 require "use_case/question/create_followers"
+require "use_case/question/destroy"
 
 class Ajax::QuestionController < AjaxController
   def destroy
     params.require :question
 
-    question = Question.find params[:question]
-    if question.nil?
-      @response[:status] = :not_found
-      @response[:message] = t(".notfound")
-      return
-    end
-
-    unless current_user&.mod? || question.user == current_user
-      @response[:status] = :not_authorized
-      @response[:message] = t(".noauth")
-      return
-    end
-
-    question.destroy!
+    UseCase::Question::Destroy.call(
+      question_id:  params[:question],
+      current_user: current_user
+    )
 
     @response[:status] = :okay
     @response[:message] = t(".success")

lib/use_case/question/destroy.rb

@@ -0,0 +1,21 @@
+# frozen_string_literal: true
+
+require "use_case/base"
+require "errors"
+
+module UseCase
+  module Question
+    class Destroy < UseCase::Base
+      option :question_id, type: Types::Coercible::Integer
+      option :current_user, type: Types::Instance(::User)
+
+      def call
+        question = ::Question.find(question_id)
+
+        raise Errors::Forbidden unless current_user&.mod? || question.user == current_user
+
+        question.destroy!
+      end
+    end
+  end
+end

spec/controllers/ajax/question_controller_spec.rb

@@ -428,7 +428,7 @@ describe Ajax::QuestionController, :ajax_controller, type: :controller do
       context "when the question exists and was not made by the current user" do
         let(:question_user) { FactoryBot.create(:user) }
 
-        include_examples "does not delete the question", "not_authorized"
+        include_examples "does not delete the question", "forbidden"
 
         %i[moderator administrator].each do |privileged_role|
           context "when the current user is a #{privileged_role}" do
@@ -446,7 +446,7 @@ describe Ajax::QuestionController, :ajax_controller, type: :controller do
       context "when the question exists and was not made by any registered user" do
         let(:question_user) { nil }
 
-        include_examples "does not delete the question", "not_authorized"
+        include_examples "does not delete the question", "forbidden"
 
         %i[moderator administrator].each do |privileged_role|
           context "when the current user is a #{privileged_role}" do
@@ -470,12 +470,14 @@ describe Ajax::QuestionController, :ajax_controller, type: :controller do
       context "when the question is an invalid value" do
         let(:question_id) { "sonic_the_hedgehog" }
 
-        include_examples "does not delete the question", "not_found"
+        # This case returns an invalid parameter error in the use case due to a type constraint
+        include_examples "does not delete the question", "err"
       end
     end
 
     context "when user is not signed in" do
-      include_examples "does not delete the question", "not_authorized"
+      # This case returns an invalid parameter error in the use case due to a type constraint
+      include_examples "does not delete the question", "err"
     end
   end
 end