some code from checkout process using artwork credits

gistfile1.rb

artwork_credit.rb

  # credit flag for this model marks whether or not it is an active credit (can be applied)
	# following two methods are used in checkout process to when artwork credits are used, turned into adjustments, and deactivated to make sure they can't be reused
	def use_credit
		self.update_column(:credit, false)
	end

	def restore_credit
		self.update_column(:credit, true)
	end

setter_methods.rb

def add_artwork_credit
    credit_amount = 0
    self.line_items.each do |li|
      if li.artwork_credit > 0
        # adds to the credit amount total that will be applied to our balance
        credit_amount += li.artwork_credit
        li.artwork_credits.each do |credit|
          credit.use_credit
        end
      end
    end

    self.adjustments.create(source: self.user.account,
                            label: "Artwork Credit",
                            amount: -credit_amount,
                            mandatory: true)

    updater.update_totals
  end

  def remove_artwork_credit
    # find artwork credit adjustments and terminate them with extreme prejudice
    adjustments = self.adjustments.where(:source_id => self.user.account.id, source_type: 'User::Account')
    adjustments.destroy_all

    # restore artwork credits that were being used in each line item
    self.line_items.each do |li|
      li.artwork_credits.each do |credit|
        credit.restore_credit
      end
    end

    updater.update_totals
  end

Destroying all adjustments on line 37 seems dangerous. What if there's a store credit, wouldn't that fall under the same parameters? Search for the label as well i guess