Shopify Scripts product set partitioner - https://www.shopify.com/partners/blog/109804486-getting-started-with-shopify-scripts-a-practical-walkthrough

shopify-scripts-product-set-partitioner.rb

class ProductSetPartitioner

  def initialize(set_product_ids)
    @set_product_ids = set_product_ids
  end

  def partition(cart, applicable_line_items)
    # If all items in the product set are in the cart, then all applicable line
    # items are eligible for the discount. Otherwise, none of them are.
    cart_product_ids = cart.line_items.map { |line_item| line_item.variant.product.id }.uniq

    if (@set_product_ids - cart_product_ids).empty?
      applicable_line_items
    else
      []
    end
  end

end