Error serializer for ActiveRecord

error_serializer.rb

module ErrorSerializer
  def ErrorSerializer.serialize(errors)
    return if errors.nil?
    
    new_hash = errors.to_hash(true).map do |k, v|
      v.map do |msg|
        { id: k, title: msg }
      end
    end
    return new_hash.flatten
  end
end

example_controller.rb

include ErrorSerializer

class Api::V1::UsersController < Api::V1::ApiController
  
  # POST '/api/v1/user'
  def create
    user = User.new(user_params)
    if user.save
      user_json = UserSerializer.new(user).attributes.as_json
      render json: user_json, status: :ok
    else
      render json: { errors: ErrorSerializer.serialize(user.errors) }, status: :bad_request
    end
  end
  
  private
    def user_params
      params.require(:user).permit(:first_name, :last_name, :email)
    end
end