token.rb

module AuthTokenConcern
  extend ActiveSupport::Concern

  included do
    before_action :unique_auth_token
  end

  def unique_auth_token
    unique_auth = false
    while unique_auth == false
      auth_key = SecureRandom.base64.tr('+/=', 'Qrt')
      if !User.all.where(auth_token: auth_key).any?
        unique_auth = true
        return auth_key
      end
    end
  end
end