user.rb

class User < ApplicationRecord

  before_create :check_user_exists

  # Include default devise modules. Others available are:
  # :confirmable, :lockable, :timeoutable and :omniauthable
  devise :database_authenticatable, :recoverable, :rememberable, :trackable, :validatable
  private

  def check_user_exists
    user = User.first_or_initialize(:email => email)
    if !user.new_record?
      if puntos >= user.puntos
        user.puntos = puntos
      end
    end
  end
end