Migrating a percentage off shipping script

危険なペア D16。このファイルと対になるファイルは見た目がほぼ同じで、動作が異なります。どちらを使っているか判断する前に両方を読んでください。

# ================================ Customizable Settings ================================
DISCOUNT_TYPE = :percent
DISCOUNT_AMOUNT = 10
DISCOUNT_MESSAGE = '10% off shipping'

# ================================ Script Code (do not edit) ================================
class DiscountApplicator
  def initialize(discount_type, discount_amount, discount_message)
    @discount_type = discount_type
    @discount_message = discount_message

    @discount_amount = if discount_type == :percent
      discount_amount * 0.01
    else
      Money.new(cents: 100) * discount_amount
    end
  end

  def apply(shipping_rate)
    discount_amount = if @discount_type == :percent
      shipping_rate.price * @discount_amount
    else
      @discount_amount > shipping_rate.price ? shipping_rate.price : @discount_amount
    end

    shipping_rate.apply_discount(discount_amount, message: @discount_message)
  end
end

class DiscountRatesCampaign
  def initialize(discount_applicator)
    @discount_applicator = discount_applicator
  end

  def run(cart, shipping_rates)
    shipping_rates.each do |shipping_rate|
      @discount_applicator.apply(shipping_rate)
    end
  end
end

CAMPAIGNS = [
  DiscountRatesCampaign.new(
    DiscountApplicator.new(DISCOUNT_TYPE, DISCOUNT_AMOUNT, DISCOUNT_MESSAGE),
  ),
]

CAMPAIGNS.each do |campaign|
  campaign.run(Input.cart, Input.shipping_rates)
end

Output.shipping_rates = Input.shipping_rates

Shipping discount として認識され、free_shipping タイプのオファーとして再構築されます。以下はオファーが実際に保存される設定キーそのものなので、ご自身の再構築結果を項目ごとに照合できます。

公開デモストア Meridian Goods で作成しているため、ここに載せた価格はすべて、信じるのではなく再現して確かめられます。以下の割引額は、決済時に動くのと同じエンジンがこのカートに対して算出した金額です。

This rule carries no condition at all, so it fires on any cart holding anything and there is no quiet cart to build. The negative check is an empty cart, which the app runs for you. That is correct behaviour, not a failure.