gistfile1.txt

class User < ApplicationRecord
  validates :sc_external_id, presence: true, uniqueness: true, length: { minimum: 10 }
  has_one :profile, dependent: :destroy

  has_many :photos, dependent: :destroy
  accepts_nested_attributes_for :photos, allow_destroy: true
  validates_associated :photos
  validate :photo_limit

  private

  def photo_limit
    errors.add(:base, "You have reached the maximum number of photos") if photos.count > 6
  end
end