[Shopify Script]

Discount Product Type A if Product type B is in cart

# EG - I want to offer 15% off all cycling bib shorts when any of our cycling jerseys are purchased. 
# Assumes no limit on how many of these products can be discounted in one cart

cartDiscountAmount = 15 # (Int) Percentage discount to apply. 15 = 15%
cartDiscountMessage = "15% off Pedla bibs" # (String) Message to apple when discounting
cartDiscountCondition = false # (Boolean) Should the cart discount conditions be applied
discountConditionalProductType = "Electronics" # (String) If this product type is in the cart other products may be discounted
discountTargetProductType = "Music" # (String) The product type that should be discounted. 


Input.cart.line_items.each do |line_item|
  puts line_item.variant.product.product_type
  if line_item.variant.product.product_type === discountConditionalProductType
    cartDiscountCondition = true
    break
  end
end

if cartDiscountCondition == true
  Input.cart.line_items.each do |line_item|
      if line_item.variant.product.product_type === discountTargetProductType
        line_item.change_line_price(line_item.line_price * (1 - (cartDiscountAmount / 100)) , message: cartDiscountMessage)
      end
  end
end

Output.cart = Input.cart