Shopify Scripts multiple components in one script example - https://www.shopify.com/partners/blog/109804486-getting-started-with-shopify-scripts-a-practical-walkthrough

shopify-scripts-multiple-components-one-scripts-example.rb

# Use an array to keep track of the discount campaigns desired.
CAMPAIGNS = [
  # $5 off all items with the "sale" tag
  ItemCampaign.new(
    AndSelector.new(
      TagSelector.new("sale"),
      ExcludeGiftCardSelector.new,
    ),
    MoneyDiscount.new(5_00, "5$ off all items on sale",),
  ),

  # 10% off all items with a price lower than $100
  ItemCampaign.new(
    AndSelector.new(
      ExcludeGiftCardSelector.new,
      PriceSelector.new(:lower_than, Money.new(cents: 100_00)),
    ),
    PercentageDiscount.new(10, "10% off all items under 100$"),
  ),

  # Give every 3rd item with the tag "letter" for free
  BogoCampaign.new(
    TagSelector.new("letter"),
    PercentageDiscount.new(100, "Third item is free"),
    LowToHighPartitioner.new(2,1),
  )
]

# Iterate through each of the discount campaigns.
CAMPAIGNS.each do |campaign|
  # Apply the campaign onto the cart.
  campaign.run(Input.cart)
end

# In order to have the changes to the line items be reflected, the output of
# the script needs to be specified.
Output.cart = Input.cart