Line item script examples

Line item scripts affect items in a cart, and can change their properties and prices. These scripts run each time that a cart attribute is changed, such as adding or removing an item, changing the shipping address, or adding a discount code.

Plan requirement

Shopify Scripts and the Script Editor app are available only to stores on the Shopify Plus plan. The Script Editor app is no longer available for download from the Shopify App Store.

On August 28, 2025, Shopify Scripts will be removed and will no longer work. Migrate your existing Scripts to Shopify Functions before this date.

To use the templates on this page, create a new script with a blank template.

Steps:

1. From your Shopify admin, go to Apps > Script Editor.
2. Click Create script.
3. Click Line items.
4. Select Blank template, then click Create script.
5. In the Ruby source code section, delete the default line of code: Output.cart = Input.cart
6. Copy a script from this page and paste it into the Ruby source code section.
7. Edit the Customizable Settings section of the script to function in your store.
8. Test your script. For more information, refer to Testing and debugging Shopify Scripts.
9. After testing:
   • click Save draft to save an unpublished draft of the script, or
   • click Save and publish to create and publish the script.

Tiered cart discount by spend

Use this script to offer a dollar amount discount that increases according to the total value of the items in their cart. This discount is spread as evenly as possible across the individual items in the cart.

For example, offer customers $25 off their total if they spend more than $150, $50 off if they spend more than $300, or $75 off if they spend more than $400.

# ================================ Customizable Settings ================================
# ================================================================
# Tiered Cart Discounts by Spend Threshold
#
# If the cart total is greater than (or equal to) an entered
# threshold, the associated discount is applied to the cart. The
# discount will be spread, as evenly as possible, across all items.
#
#   - 'threshold' is the spend amount needed to qualify
#   - 'discount_amount' is the dollar discount to apply to the
#     cart
#   - 'discount_message' is the message to show when a discount
#     is applied
# ================================================================
SPENDING_THRESHOLDS = [
  {
    threshold: 150,
    discount_amount: 25,
    discount_message: 'Spend $150 and get $25 off!',
  },
  {
    threshold: 300,
    discount_amount: 50,
    discount_message: 'Spend $300 and get $50 off!',
  },
  {
    threshold: 400,
    discount_amount: 75,
    discount_message: 'Spend $400 and get $75 off!',
  },
]

# ================================ Script Code (do not edit) ================================
# ================================================================
# DollarDiscountApplicator
#
# Applies the entered discount to the supplied line item.
# ================================================================
class DollarDiscountApplicator
  def initialize(discount_message)
    @discount_message = discount_message
  end

  def apply(line_item, discount_amount)
    new_line_price = line_item.line_price - discount_amount
    line_item.change_line_price(new_line_price, message: @discount_message)
  end
end

# ================================================================
# TieredCartDiscountBySpendCampaign
#
# If the cart total is greater than (or equal to) an entered
# threshold, the associated discount is applied to the cart. The
# discount will be spread, as evenly as possible, across all items.
# ================================================================
class TieredCartDiscountBySpendCampaign
  def initialize(tiers)
    @tiers = tiers.sort_by { |tier| tier[:threshold] }.reverse
  end

  def run(cart)
    applicable_tier = @tiers.find { |tier| cart.subtotal_price >= (Money.new(cents: 100) * tier[:threshold]) }
    return if applicable_tier.nil?

    discount_applicator = DollarDiscountApplicator.new(applicable_tier[:discount_message])
    discount_amount = applicable_tier[:discount_amount]
    items = cart.line_items.sort_by { |line_item| line_item.variant.price }
    self.loop_items(cart, items, discount_amount, discount_applicator)
  end

  def loop_items(cart, line_items, discount_amount, discount_applicator)
    avg_discount = (discount_amount.to_f * (1 / line_items.map(&:quantity).reduce(0, :+))).round(2)
    avg_discount = Money.new(cents: 100) * avg_discount
    discount_amount = Money.new(cents: 100) * discount_amount

    line_items.each_with_index do |line_item, index|
      break if discount_amount <= Money.zero

      line_discount = avg_discount * line_item.quantity

      if discount_amount < line_discount || index == (line_items.size - 1)
        discount_update = line_item.line_price > discount_amount ? discount_amount : line_item.line_price
      else
        discount_update = line_item.line_price > line_discount ? line_discount : line_item.line_price
      end

      discount_amount -= discount_update
      discount_applicator.apply(line_item, discount_update)
    end
  end
end

CAMPAIGNS = [
  TieredCartDiscountBySpendCampaign.new(SPENDING_THRESHOLDS),
]

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

Output.cart = Input.cart

Tiered discount by spend

Use this script to offer a percentage discount that increases according to the total value of the items in their cart.

For example, offer customers 10% off if they spend $30 or more, 15% off if they spend $50 or more, or 20% off if they spend $100 or more.

# ================================ Customizable Settings ================================
# ================================================================
# Tiered Discounts by Spend Threshold
#
# If the cart total is greater than (or equal to) an entered
# threshold, the associated discount is applied to each item.
#
#   - 'threshold' is the spend amount needed to qualify
#   - 'discount_type' is the type of discount to provide. Can be
#     either:
#       - ':percent'
#       - ':dollar'
#   - 'discount_amount' is the percentage/dollar discount to
#     apply (per item)
#   - 'discount_message' is the message to show when a discount
#     is applied
# ================================================================
SPENDING_THRESHOLDS = [
  {
    threshold: 30,
    discount_type: :percent,
    discount_amount: 10,
    discount_message: 'Spend $30 and get 10% off!',
  },
  {
    threshold: 50,
    discount_type: :percent,
    discount_amount: 15,
    discount_message: 'Spend $50 and get 15% off!',
  },
  {
    threshold: 100,
    discount_type: :percent,
    discount_amount: 20,
    discount_message: 'Spend $100 and get 20% off!',
  },
]

# ================================ Script Code (do not edit) ================================
# ================================================================
# DiscountApplicator
#
# Applies the entered discount to the supplied line item.
# ================================================================
class DiscountApplicator
  def initialize(discount_type, discount_amount, discount_message)
    @discount_type = discount_type
    @discount_message = discount_message

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

  def apply(line_item)
    new_line_price = if @discount_type == :percent
      line_item.line_price * @discount_amount
    else
      [line_item.line_price - (@discount_amount * line_item.quantity), Money.zero].max
    end

    line_item.change_line_price(new_line_price, message: @discount_message)
  end
end

# ================================================================
# TieredDiscountBySpendCampaign
#
# If the cart total is greater than (or equal to) an entered
# threshold, the associated discount is applied to each item.
# ================================================================
class TieredDiscountBySpendCampaign
  def initialize(tiers)
    @tiers = tiers.sort_by { |tier| tier[:threshold] }.reverse
  end

  def run(cart)
    applicable_tier = @tiers.find { |tier| cart.subtotal_price >= (Money.new(cents: 100) * tier[:threshold]) }
    return if applicable_tier.nil?

    discount_applicator = DiscountApplicator.new(
      applicable_tier[:discount_type],
      applicable_tier[:discount_amount],
      applicable_tier[:discount_message]
    )

    cart.line_items.each do |line_item|
      next if line_item.variant.product.gift_card?
      discount_applicator.apply(line_item)
    end
  end
end

CAMPAIGNS = [
  TieredDiscountBySpendCampaign.new(SPENDING_THRESHOLDS),
]

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

Output.cart = Input.cart

Tiered product discount by quantity

Use this script to offer a bulk discount for a particular product, with a percentage discount that increases according to the number of those products in the cart.

For example, offer customers 10% off each hat if they purchase 2 hats or more, or 15% off if they purchase 5 hats or more.

# ================================ Customizable Settings ================================
# ================================================================
# Tiered Product Discount by Quantity
#
# If the total quantity of matching items is greater than (or
# equal to) an entered threshold, the associated discount is
# applied to each matching item.
#
#   - 'product_selector_match_type' determines whether we look for
#     products that do or don't match the entered selectors. Can
#     be:
#       - ':include' to check if the product does match
#       - ':exclude' to make sure the product doesn't match
#   - 'product_selector_type' determines how eligible products
#     will be identified. Can be either:
#       - ':tag' to find products by tag
#       - ':type' to find products by type
#       - ':vendor' to find products by vendor
#       - ':product_id' to find products by ID
#       - ':variant_id' to find products by variant ID
#       - ':subscription' to find subscription products
#       - ':all' for all products
#   - 'product_selectors' is a list of identifiers (from above) for
#     qualifying products. Product/Variant ID lists should only
#     contain numbers (ie. no quotes). If ':all' is used, this
#     can also be 'nil'.
#   - 'tiers' is a list of tiers where:
#     - 'quantity' is the minimum quantity you need to buy to
#       qualify
#     - 'discount_type' is the type of discount to provide. Can be
#       either:
#         - ':percent'
#         - ':dollar'
#     - 'discount_amount' is the percentage/dollar discount to
#       apply (per item)
#     - 'discount_message' is the message to show when a discount
#       is applied
# ================================================================
PRODUCT_DISCOUNT_TIERS = [
  {
    product_selector_match_type: :include,
    product_selector_type: :tag,
    product_selectors: ["your_tag"],
    tiers: [
      {
        quantity: 2,
        discount_type: :percent,
        discount_amount: 10,
        discount_message: '10% off for 2+',
      },
      {
        quantity: 5,
        discount_type: :percent,
        discount_amount: 15,
        discount_message: '15% off for 5+',
      },
    ],
  },
]

# ================================ Script Code (do not edit) ================================
# ================================================================
# ProductSelector
#
# Finds matching products by the entered criteria.
# ================================================================
class ProductSelector
  def initialize(match_type, selector_type, selectors)
    @match_type = match_type
    @comparator = match_type == :include ? 'any?' : 'none?'
    @selector_type = selector_type
    @selectors = selectors
  end

  def match?(line_item)
    if self.respond_to?(@selector_type)
      self.send(@selector_type, line_item)
    else
      raise RuntimeError.new('Invalid product selector type')
    end
  end

  def tag(line_item)
    product_tags = line_item.variant.product.tags.map { |tag| tag.downcase.strip }
    @selectors = @selectors.map { |selector| selector.downcase.strip }
    (@selectors & product_tags).send(@comparator)
  end

  def type(line_item)
    @selectors = @selectors.map { |selector| selector.downcase.strip }
    (@match_type == :include) == @selectors.include?(line_item.variant.product.product_type.downcase.strip)
  end

  def vendor(line_item)
    @selectors = @selectors.map { |selector| selector.downcase.strip }
    (@match_type == :include) == @selectors.include?(line_item.variant.product.vendor.downcase.strip)
  end

  def product_id(line_item)
    (@match_type == :include) == @selectors.include?(line_item.variant.product.id)
  end

  def variant_id(line_item)
    (@match_type == :include) == @selectors.include?(line_item.variant.id)
  end

  def subscription(line_item)
    !line_item.selling_plan_id.nil?
  end

  def all(line_item)
    true
  end
end

# ================================================================
# DiscountApplicator
#
# Applies the entered discount to the supplied line item.
# ================================================================
class DiscountApplicator
  def initialize(discount_type, discount_amount, discount_message)
    @discount_type = discount_type
    @discount_message = discount_message

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

  def apply(line_item)
    new_line_price = if @discount_type == :percent
      line_item.line_price * @discount_amount
    else
      [line_item.line_price - (@discount_amount * line_item.quantity), Money.zero].max
    end

    line_item.change_line_price(new_line_price, message: @discount_message)
  end
end

# ================================================================
# TieredProductDiscountByQuantityCampaign
#
# If the total quantity of matching items is greater than (or
# equal to) an entered threshold, the associated discount is
# applied to each matching item.
# ================================================================
class TieredProductDiscountByQuantityCampaign
  def initialize(campaigns)
    @campaigns = campaigns
  end

  def run(cart)
    @campaigns.each do |campaign|
      product_selector = ProductSelector.new(
        campaign[:product_selector_match_type],
        campaign[:product_selector_type],
        campaign[:product_selectors],
      )

      applicable_items = cart.line_items.select { |line_item| product_selector.match?(line_item) }

      next if applicable_items.nil?

      total_applicable_quantity = applicable_items.map(&:quantity).reduce(0, :+)
      tiers = campaign[:tiers].sort_by { |tier| tier[:quantity] }.reverse
      applicable_tier = tiers.find { |tier| tier[:quantity] <= total_applicable_quantity }

      next if applicable_tier.nil?

      discount_applicator = DiscountApplicator.new(
        applicable_tier[:discount_type],
        applicable_tier[:discount_amount],
        applicable_tier[:discount_message]
      )

      applicable_items.each do |line_item|
        discount_applicator.apply(line_item)
      end
    end
  end
end

CAMPAIGNS = [
  TieredProductDiscountByQuantityCampaign.new(PRODUCT_DISCOUNT_TIERS),
]

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

Output.cart = Input.cart

Tiered product discount by product spend

Use this script to offer a percentage discount that increases according to the total value of specific items in the cart.

For example, offer customers 10% off if they spend $30 or more, 15% off if they spend $50 or more, and 20% off if they spend $100 or more, but only for items that match a specific tag.

# ================================ Customizable Settings ================================
# ================================================================
# Tiered Product Discount by Product Spend Threhsold
#
# If the total amount spent on matching items is greather than (or
# equal to) an entered threshold, the associated discount is
# applied to each matching item.
#
#   - 'product_selector_match_type' determines whether we look for
#     products that do or don't match the entered selectors. Can
#     be:
#       - ':include' to check if the product does match
#       - ':exclude' to make sure the product doesn't match
#   - 'product_selector_type' determines how eligible products
#     will be identified. Can be either:
#       - ':tag' to find products by tag
#       - ':type' to find products by type
#       - ':vendor' to find products by vendor
#       - ':product_id' to find products by ID
#       - ':variant_id' to find products by variant ID
#       - ':subscription' to find subscription products
#       - ':all' for all products
#   - 'product_selectors' is a list of identifiers (from above)
#     for qualifying products. Product/Variant ID lists should
#     only contain numbers (ie. no quotes). If ':all' is used,
#     this can also be 'nil'.
#   - 'tiers' is a list of tiers where:
#     - 'threshold' is the minimum dollar amount needed to
#       qualify
#     - 'discount_type' is the type of discount to provide. Can be
#       either:
#         - ':percent'
#         - ':dollar'
#     - 'discount_amount' is the percentage/dollar discount to
#       apply (per item)
#     - 'discount_message' is the message to show when a discount
#       is applied
# ================================================================
PRODUCT_DISCOUNT_TIERS = [
  {
    product_selector_match_type: :exclude,
    product_selector_type: :tag,
    product_selectors: ["your_tag", "another_tag"],
    tiers: [
      {
        threshold: 100,
        discount_type: :percent,
        discount_amount: 10,
        discount_message: 'Spend $100 or more, and get 10% off!',
      },
    ],
  },
]

# ================================ Script Code (do not edit) ================================
# ================================================================
# ProductSelector
#
# Finds matching products by the entered criteria.
# ================================================================
class ProductSelector
  def initialize(match_type, selector_type, selectors)
    @match_type = match_type
    @comparator = match_type == :include ? 'any?' : 'none?'
    @selector_type = selector_type
    @selectors = selectors
  end

  def match?(line_item)
    if self.respond_to?(@selector_type)
      self.send(@selector_type, line_item)
    else
      raise RuntimeError.new('Invalid product selector type')
    end
  end

  def tag(line_item)
    product_tags = line_item.variant.product.tags.map { |tag| tag.downcase.strip }
    @selectors = @selectors.map { |selector| selector.downcase.strip }
    (@selectors & product_tags).send(@comparator)
  end

  def type(line_item)
    @selectors = @selectors.map { |selector| selector.downcase.strip }
    (@match_type == :include) == @selectors.include?(line_item.variant.product.product_type.downcase.strip)
  end

  def vendor(line_item)
    @selectors = @selectors.map { |selector| selector.downcase.strip }
    (@match_type == :include) == @selectors.include?(line_item.variant.product.vendor.downcase.strip)
  end

  def product_id(line_item)
    (@match_type == :include) == @selectors.include?(line_item.variant.product.id)
  end

  def variant_id(line_item)
    (@match_type == :include) == @selectors.include?(line_item.variant.id)
  end

  def subscription(line_item)
    !line_item.selling_plan_id.nil?
  end

  def all(line_item)
    true
  end
end

# ================================================================
# DiscountApplicator
#
# Applies the entered discount to the supplied line item.
# ================================================================
class DiscountApplicator
  def initialize(discount_type, discount_amount, discount_message)
    @discount_type = discount_type
    @discount_message = discount_message

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

  def apply(line_item)
    new_line_price = if @discount_type == :percent
      line_item.line_price * @discount_amount
    else
      [line_item.line_price - (@discount_amount * line_item.quantity), Money.zero].max
    end

    line_item.change_line_price(new_line_price, message: @discount_message)
  end
end

# ================================================================
# TieredProductDiscountByProductSpendCampaign
#
# If the total amount spent on matching items is greather than (or
# equal to) an entered threshold, the associated discount is
# applied to each matching item.
# ================================================================
class TieredProductDiscountByProductSpendCampaign
  def initialize(campaigns)
    @campaigns = campaigns
  end

  def run(cart)
    @campaigns.each do |campaign|
      if campaign[:product_selector_type] == :all
        total_applicable_cost = cart.subtotal_price
        applicable_items = cart.line_items
      else
        product_selector = ProductSelector.new(
          campaign[:product_selector_match_type],
          campaign[:product_selector_type],
          campaign[:product_selectors],
        )

        applicable_items = cart.line_items.select { |line_item| product_selector.match?(line_item) }

        next if applicable_items.nil?

        total_applicable_cost = applicable_items.map(&:line_price).reduce(Money.zero, :+)
      end

      tiers = campaign[:tiers].sort_by { |tier| tier[:threshold] }.reverse
      applicable_tier = tiers.find { |tier|  total_applicable_cost >= (Money.new(cents: 100) * tier[:threshold]) }

      next if applicable_tier.nil?

      discount_applicator = DiscountApplicator.new(
        applicable_tier[:discount_type],
        applicable_tier[:discount_amount],
        applicable_tier[:discount_message]
      )

      applicable_items.each do |line_item|
        discount_applicator.apply(line_item)
      end
    end
  end
end

CAMPAIGNS = [
  TieredProductDiscountByProductSpendCampaign.new(PRODUCT_DISCOUNT_TIERS),
]

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

Output.cart = Input.cart

Product discount

Use this script to offer a discount on specific items.

For example, offer customers 10% off on items tagged discounted.

# ================================ Customizable Settings ================================
# ================================================================
# Discount by Product
#
# Any matching item will be discounted by the entered amount.
#
#   - 'product_selector_match_type' determines whether we look for
#     products that do or don't match the entered selectors. Can
#     be:
#       - ':include' to check if the product does match
#       - ':exclude' to make sure the product doesn't match
#   - 'product_selector_type' determines how eligible products
#     will be identified. Can be either:
#       - ':tag' to find products by tag
#       - ':type' to find products by type
#       - ':vendor' to find products by vendor
#       - ':product_id' to find products by ID
#       - ':variant_id' to find products by variant ID
#       - ':subscription' to find subscription products
#       - ':all' for all products
#   - 'product_selectors' is a list of identifiers (from above)
#     for qualifying products. Product/Variant ID lists should
#     only contain numbers (ie. no quotes). If ':all' is used,
#     this can also be 'nil'.
#   - 'discount_type' is the type of discount to provide. Can be
#     either:
#       - ':percent'
#       - ':dollar'
#   - 'discount_amount' is the percentage/dollar discount to
#     apply (per item)
#   - 'discount_message' is the message to show when a discount
#     is applied
# ================================================================
PRODUCT_DISCOUNTS = [
  {
    product_selector_match_type: :include,
    product_selector_type: :tag,
    product_selectors: ["your_tag"],
    discount_type: :percent,
    discount_amount: 10,
    discount_message: '10% off tagged products!'
  }
]

# ================================ Script Code (do not edit) ================================
# ================================================================
# ProductSelector
#
# Finds matching products by the entered criteria.
# ================================================================
class ProductSelector
  def initialize(match_type, selector_type, selectors)
    @match_type = match_type
    @comparator = match_type == :include ? 'any?' : 'none?'
    @selector_type = selector_type
    @selectors = selectors
  end

  def match?(line_item)
    if self.respond_to?(@selector_type)
      self.send(@selector_type, line_item)
    else
      raise RuntimeError.new('Invalid product selector type')
    end
  end

  def tag(line_item)
    product_tags = line_item.variant.product.tags.map { |tag| tag.downcase.strip }
    @selectors = @selectors.map { |selector| selector.downcase.strip }
    (@selectors & product_tags).send(@comparator)
  end

  def type(line_item)
    @selectors = @selectors.map { |selector| selector.downcase.strip }
    (@match_type == :include) == @selectors.include?(line_item.variant.product.product_type.downcase.strip)
  end

  def vendor(line_item)
    @selectors = @selectors.map { |selector| selector.downcase.strip }
    (@match_type == :include) == @selectors.include?(line_item.variant.product.vendor.downcase.strip)
  end

  def product_id(line_item)
    (@match_type == :include) == @selectors.include?(line_item.variant.product.id)
  end

  def variant_id(line_item)
    (@match_type == :include) == @selectors.include?(line_item.variant.id)
  end

  def subscription(line_item)
    !line_item.selling_plan_id.nil?
  end

  def all(line_item)
    true
  end
end

# ================================================================
# DiscountApplicator
#
# Applies the entered discount to the supplied line item.
# ================================================================
class DiscountApplicator
  def initialize(discount_type, discount_amount, discount_message)
    @discount_type = discount_type
    @discount_message = discount_message

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

  def apply(line_item)
    new_line_price = if @discount_type == :percent
      line_item.line_price * @discount_amount
    else
      [line_item.line_price - (@discount_amount * line_item.quantity), Money.zero].max
    end

    line_item.change_line_price(new_line_price, message: @discount_message)
  end
end

# ================================================================
# ProductDiscountCampaign
#
# Any matching item will be discounted by the entered amount.
# ================================================================
class ProductDiscountCampaign
  def initialize(campaigns)
    @campaigns = campaigns
  end

  def run(cart)
    @campaigns.each do |campaign|
      product_selector = ProductSelector.new(
        campaign[:product_selector_match_type],
        campaign[:product_selector_type],
        campaign[:product_selectors],
      )

      discount_applicator = DiscountApplicator.new(
        campaign[:discount_type],
        campaign[:discount_amount],
        campaign[:discount_message]
      )

      cart.line_items.each do |line_item|
        next unless product_selector.match?(line_item)
        discount_applicator.apply(line_item)
      end
    end
  end
end

CAMPAIGNS = [
  ProductDiscountCampaign.new(PRODUCT_DISCOUNTS),
]

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

Output.cart = Input.cart

Product discount by discount code

Use this script to offer a discount on specific items if a specific discount code is used.

For example, offer customers 10% off on items tagged discounted if they use the discount code DISCOUNT_10.

# ================================ Customizable Settings ================================
# ================================================================
# Product Discount by Discount Code
#
# If any matching discount codes are used, any matching items
# will be discounted by the entered amount.
#
#   - 'discount_code_match_type' determines whether the below
#     strings should be an exact or partial match. Can be:
#       - ':exact' for an exact match
#       - ':partial' for a partial match
#   - 'discount_codes' is a list of strings to identify discount
#     codes
#   - 'product_selector_match_type' determines whether we look for
#     products that do or don't match the entered selectors. Can
#     be:
#       - ':include' to check if the product does match
#       - ':exclude' to make sure the product doesn't match
#   - 'product_selector_type' determines how eligible products
#     will be identified. Can be either:
#       - ':tag' to find products by tag
#       - ':type' to find products by type
#       - ':vendor' to find products by vendor
#       - ':product_id' to find products by ID
#       - ':variant_id' to find products by variant ID
#       - ':subscription' to find subscription products
#       - ':all' for all products
#   - 'product_selectors' is a list of identifiers (from above)
#     for qualifying products. Product/Variant ID lists should
#     only contain numbers (ie. no quotes). If ':all' is used,
#     this can also be 'nil'.
#   - 'discount_type' is the type of discount to provide. Can be
#     either:
#       - ':percent'
#       - ':dollar'
#   - 'discount_amount' is the percentage/dollar discount to
#     apply (per item)
#   - 'discount_message' is the message to show when a discount
#     is applied
# ================================================================
PRODUCT_DISCOUNTS_BY_DISCOUNT_CODE = [
  {
    discount_code_match_type: :exact,
    discount_codes: ["TESTCODE1", "TESTCODE2"],
    product_selector_match_type: :include,
    product_selector_type: :tag,
    product_selectors: ["your_tag"],
    discount_type: :percent,
    discount_amount: 10,
    discount_message: '10% off tagged products!'
  }
]

# ================================ Script Code (do not edit) ================================
# ================================================================
# DiscountCodeSelector
#
# Finds whether the supplied discount code matches any of the
# entered codes.
# ================================================================
class DiscountCodeSelector
  def initialize(match_type, discount_codes)
    @comparator = match_type == :exact ? '==' : 'include?'
    @discount_codes = discount_codes.map { |discount_code| discount_code.upcase.strip }
  end

  def match?(discount_code)
    @discount_codes.any? { |code| discount_code.code.upcase.send(@comparator, code) }
  end
end

# ================================================================
# ProductSelector
#
# Finds matching products by the entered criteria.
# ================================================================
class ProductSelector
  def initialize(match_type, selector_type, selectors)
    @match_type = match_type
    @comparator = match_type == :include ? 'any?' : 'none?'
    @selector_type = selector_type
    @selectors = selectors
  end

  def match?(line_item)
    if self.respond_to?(@selector_type)
      self.send(@selector_type, line_item)
    else
      raise RuntimeError.new('Invalid product selector type')
    end
  end

  def tag(line_item)
    product_tags = line_item.variant.product.tags.map { |tag| tag.downcase.strip }
    @selectors = @selectors.map { |selector| selector.downcase.strip }
    (@selectors & product_tags).send(@comparator)
  end

  def type(line_item)
    @selectors = @selectors.map { |selector| selector.downcase.strip }
    (@match_type == :include) == @selectors.include?(line_item.variant.product.product_type.downcase.strip)
  end

  def vendor(line_item)
    @selectors = @selectors.map { |selector| selector.downcase.strip }
    (@match_type == :include) == @selectors.include?(line_item.variant.product.vendor.downcase.strip)
  end

  def product_id(line_item)
    (@match_type == :include) == @selectors.include?(line_item.variant.product.id)
  end

  def variant_id(line_item)
    (@match_type == :include) == @selectors.include?(line_item.variant.id)
  end

  def subscription(line_item)
    !line_item.selling_plan_id.nil?
  end

  def all(line_item)
    true
  end
end

# ================================================================
# DiscountApplicator
#
# Applies the entered discount to the supplied line item.
# ================================================================
class DiscountApplicator
  def initialize(discount_type, discount_amount, discount_message)
    @discount_type = discount_type
    @discount_message = discount_message

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

  def apply(line_item)
    new_line_price = if @discount_type == :percent
      line_item.line_price * @discount_amount
    else
      [line_item.line_price - (@discount_amount * line_item.quantity), Money.zero].max
    end

    line_item.change_line_price(new_line_price, message: @discount_message)
  end
end

# ================================================================
# ProductDiscountByCodeCampaign
#
# If any matching discount codes are used, any matching items
# will be discounted by the entered amount.
# ================================================================
class ProductDiscountByCodeCampaign
  def initialize(campaigns)
    @campaigns = campaigns
  end

  def run(cart)
    return if cart.discount_code.nil?

    @campaigns.each do |campaign|
      discount_code_selector = DiscountCodeSelector.new(
        campaign[:discount_code_match_type],
        campaign[:discount_codes]
      )

      next unless discount_code_selector.match?(cart.discount_code)

      product_selector = ProductSelector.new(
        campaign[:product_selector_match_type],
        campaign[:product_selector_type],
        campaign[:product_selectors],
      )

      discount_applicator = DiscountApplicator.new(
        campaign[:discount_type],
        campaign[:discount_amount],
        campaign[:discount_message]
      )

      cart.line_items.each do |line_item|
        next unless product_selector.match?(line_item)
        discount_applicator.apply(line_item)
      end
    end
  end
end

CAMPAIGNS = [
  ProductDiscountByCodeCampaign.new(PRODUCT_DISCOUNTS_BY_DISCOUNT_CODE),
]

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

Output.cart = Input.cart

Buy a specific amount of a product, get a second amount at a discount

Use this script to offer a discount on a specific item if more than a certain quantity is purchased.

For example, offer customers to buy three items tagged discount and receive 50% off a fourth item tagged discount.

Note

This script will not add the 'get' items to the cart. It can only discount items that are already in the cart.

# ================================ Customizable Settings ================================
# ================================================================
# Buy X, Get Y For Z Discount
#
# Buy a certain number of matching items, get a certain number
# of the same matching items with the entered discount applied. For
# example:
#
#   "Buy 2 products tagged with 'tag', get another product
#    tagged with 'tag' for 10% off"
#
#   - 'product_selector_match_type' determines whether we look for
#     products that do or don't match the entered selectors. Can
#     be:
#       - ':include' to check if the product does match
#       - ':exclude' to make sure the product doesn't match
#   - 'product_selector_type' determines how eligible products
#     will be identified. Can be either:
#       - ':tag' to find products by tag
#       - ':type' to find products by type
#       - ':vendor' to find products by vendor
#       - ':product_id' to find products by ID
#       - ':variant_id' to find products by variant ID
#       - ':subscription' to find subscription products
#       - ':all' for all products
#   - 'product_selectors' is a list of identifiers (from above) for
#     qualifying products. Product/Variant ID lists should only
#     contain numbers (ie. no quotes). If ':all' is used, this
#     can also be 'nil'.
#   - 'quantity_to_buy' is the number of products needed to
#     qualify
#   - 'quantity_to_discount' is the number of products to discount
#   - 'discount_type' is the type of discount to provide. Can be
#     either:
#       - ':percent'
#       - ':dollar'
#   - 'discount_amount' is the percentage/dollar discount to
#     apply (per item)
#   - 'discount_message' is the message to show when a discount
#     is applied
#
# Something to note for the case of running multiple offers is
# that there shouldn't be any overlap between product selection
# as this can lead to extra discounting. For example, you should
# NOT offer "Buy 1 Product X, get 1 50% off", as well as "Buy 2
# Product X, get 1 free"
# ================================================================
BUY_X_GET_Y_FOR_Z = [
  {
    product_selector_match_type: :include,
    product_selector_type: :all,
    product_selectors: nil,
    quantity_to_buy: 1,
    quantity_to_discount: 1,
    discount_type: :percent,
    discount_amount: 50,
    discount_message: 'Buy one item, get the second 50% off!',
  },
]

# ================================ Script Code (do not edit) ================================
# ================================================================
# ProductSelector
#
# Finds matching products by the entered criteria.
# ================================================================
class ProductSelector
  def initialize(match_type, selector_type, selectors)
    @match_type = match_type
    @comparator = match_type == :include ? 'any?' : 'none?'
    @selector_type = selector_type
    @selectors = selectors
  end

  def match?(line_item)
    if self.respond_to?(@selector_type)
      self.send(@selector_type, line_item)
    else
      raise RuntimeError.new('Invalid product selector type')
    end
  end

  def tag(line_item)
    product_tags = line_item.variant.product.tags.map { |tag| tag.downcase.strip }
    @selectors = @selectors.map { |selector| selector.downcase.strip }
    (@selectors & product_tags).send(@comparator)
  end

  def type(line_item)
    @selectors = @selectors.map { |selector| selector.downcase.strip }
    (@match_type == :include) == @selectors.include?(line_item.variant.product.product_type.downcase.strip)
  end

  def vendor(line_item)
    @selectors = @selectors.map { |selector| selector.downcase.strip }
    (@match_type == :include) == @selectors.include?(line_item.variant.product.vendor.downcase.strip)
  end

  def product_id(line_item)
    (@match_type == :include) == @selectors.include?(line_item.variant.product.id)
  end

  def variant_id(line_item)
    (@match_type == :include) == @selectors.include?(line_item.variant.id)
  end

  def subscription(line_item)
    !line_item.selling_plan_id.nil?
  end

  def all(line_item)
    true
  end
end

# ================================================================
# DiscountApplicator
#
# Applies the entered discount to the supplied line item.
# ================================================================
class DiscountApplicator
  def initialize(discount_type, discount_amount, discount_message)
    @discount_type = discount_type
    @discount_message = discount_message

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

  def apply(line_item)
    new_line_price = if @discount_type == :percent
      line_item.line_price * @discount_amount
    else
      [line_item.line_price - (@discount_amount * line_item.quantity), Money.zero].max
    end

    line_item.change_line_price(new_line_price, message: @discount_message)
  end
end

# ================================================================
# BuyXGetYForZCampaign
#
# Buy a certain number of matching items, get a certain number
# of the same matching items with the entered discount applied.
# ================================================================
class BuyXGetYForZCampaign
  def initialize(campaigns)
    @campaigns = campaigns
  end

  def run(cart)
    @campaigns.each do |campaign|
      product_selector = ProductSelector.new(
        campaign[:product_selector_match_type],
        campaign[:product_selector_type],
        campaign[:product_selectors],
      )

      eligible_items = cart.line_items.select { |line_item| product_selector.match?(line_item) }

      next if eligible_items.nil?

      eligible_items = eligible_items.sort_by { |line_item| -line_item.variant.price }
      quantity_to_buy = campaign[:quantity_to_buy]
      quantity_to_discount = campaign[:quantity_to_discount]
      bundle_size = quantity_to_buy + quantity_to_discount
      number_of_bundles = (eligible_items.map(&:quantity).reduce(0, :+) / bundle_size).floor
      number_of_discountable_items = number_of_bundles * quantity_to_discount

      next unless number_of_discountable_items > 0

      discount_applicator = DiscountApplicator.new(
        campaign[:discount_type],
        campaign[:discount_amount],
        campaign[:discount_message]
      )

      self.loop_items(
        discount_applicator, cart, eligible_items, number_of_discountable_items, quantity_to_buy, quantity_to_discount
      )
    end
  end

  def loop_items(discount_applicator, cart, line_items, num_to_discount, quantity_to_buy, quantity_to_discount)
    surplus = 0
    bundle_size = quantity_to_buy + quantity_to_discount

    line_items.each do |line_item|
      line_quantity = line_item.quantity + surplus

      if line_quantity > quantity_to_buy
        bundles_per_line = (line_quantity / bundle_size).floor
        take_quantity = bundles_per_line * quantity_to_discount
        surplus += (line_quantity - (bundle_size * bundles_per_line))

        if line_item.quantity > take_quantity
          discount_item = line_item.split(take: take_quantity)
          discount_applicator.apply(discount_item)
          position = cart.line_items.find_index(line_item)
          cart.line_items.insert(position + 1, discount_item)
          num_to_discount -= take_quantity
        else
          discount_applicator.apply(line_item)
          num_to_discount -= line_item.quantity
        end
      else
        surplus += line_quantity
      end

      break if num_to_discount <= 0
    end
  end
end

CAMPAIGNS = [
  BuyXGetYForZCampaign.new(BUY_X_GET_Y_FOR_Z),
]

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

Output.cart = Input.cart

Buy a bundle, get an additional product at a discount

Use this script to offer a discount on a specific item if they have purchased a number of other items.

For example, offer customers a free pair of socks if they also purchase a hat, a t-shirt, and a pair of sunglasses.

Note

This script will not add the 'get' item(s) to the cart. It can only discount items that are already in the cart.

# ================================ Customizable Settings ================================
# ================================================================
# Buy Products VWX, get Product Y for Z Discount
#
# Buy a specific bundle of items, get another item at a discount.
# For example:
#
#   "Buy a t-shirt, a hat, and sunglasses, get a free pair of socks"
#
#   - 'bundle_items' is a list of the items that comprise the
#     bundle, where:
#     - 'product_id' is the ID of the product
#     - 'quantity_needed' is the quantity necessary to complete
#       the bundle
#   - 'quantity_to_buy' is the number of bundles needed to qualify
#     for a discount product
#   - 'discount_product_selector_match_type' determines whether we
#     look for products that do or don't match the entered
#     selectors. Can be:
#       - ':include' to check if the product does match
#       - ':exclude' to make sure the product doesn't match
#   - 'discount_product_selector_type' determines how qualifying
#     products will be identified. Can be either:
#       - ':tag' to find products by tag
#       - ':type' to find products by type
#       - ':vendor' to find products by vendor
#       - ':product_id' to find products by ID
#       - ':variant_id' to find products by variant ID
#       - ':subscription' to find subscription products
#       - ':all' for all products
#   - 'discount_product_selectors' is a list of identifiers (from
#     above) for qualifying products. Product/Variant ID lists
#     should only contain numbers (ie. no quotes). If ':all' is
#     used, this can also be 'nil'.
#   - 'quantity_to_discount' is the number of items to discount
#     per offer
#   - 'discount_type' is the type of discount to provide. Can be
#     either:
#       - ':percent'
#       - ':dollar'
#   - 'discount_amount' is the percentage/dollar discount to
#     apply (per item)
#   - 'discount_message' is the message to show when a discount
#     is applied
# ================================================================
BUNDLE_DISCOUNTS = [
  {
    bundle_items: [
      {
        product_id: 1234567890987,
        quantity_needed: 1
      },
      {
        product_id: 1234567890986,
        quantity_needed: 1
      },
    ],
    quantity_to_buy: 1,
    discount_product_selector_match_type: :include,
    discount_product_selector_type: :product_id,
    discount_product_selectors: [1234567890123],
    quantity_to_discount: 1,
    discount_type: :percent,
    discount_amount: 10,
    discount_message: "Buy Product VWX, get Product Y for 10% off",
  },
]

# ================================ Script Code (do not edit) ================================
# ================================================================
# BundleSelector
#
# Finds any items that are part of the entered bundle and saves
# them.
# ================================================================
class BundleSelector
  def initialize(bundle_items)
    @bundle_items = bundle_items.reduce({}) do |acc, bundle_item|
      acc[bundle_item[:product_id]] = {
        cart_items: [],
        quantity_needed: bundle_item[:quantity_needed],
        total_quantity: 0,
      }

      acc
    end
  end

  def build(cart)
    cart.line_items.each do |line_item|
      next unless @bundle_items[line_item.variant.product.id]

      @bundle_items[line_item.variant.product.id][:cart_items].push(line_item)
      @bundle_items[line_item.variant.product.id][:total_quantity] += line_item.quantity
    end

    @bundle_items
  end
end

# ================================================================
# ProductSelector
#
# Finds matching products by the entered criteria.
# ================================================================
class ProductSelector
  def initialize(match_type, selector_type, selectors)
    @match_type = match_type
    @comparator = match_type == :include ? 'any?' : 'none?'
    @selector_type = selector_type
    @selectors = selectors
  end

  def match?(line_item)
    if self.respond_to?(@selector_type)
      self.send(@selector_type, line_item)
    else
      raise RuntimeError.new('Invalid product selector type')
    end
  end

  def tag(line_item)
    product_tags = line_item.variant.product.tags.map { |tag| tag.downcase.strip }
    @selectors = @selectors.map { |selector| selector.downcase.strip }
    (@selectors & product_tags).send(@comparator)
  end

  def type(line_item)
    @selectors = @selectors.map { |selector| selector.downcase.strip }
    (@match_type == :include) == @selectors.include?(line_item.variant.product.product_type.downcase.strip)
  end

  def vendor(line_item)
    @selectors = @selectors.map { |selector| selector.downcase.strip }
    (@match_type == :include) == @selectors.include?(line_item.variant.product.vendor.downcase.strip)
  end

  def product_id(line_item)
    (@match_type == :include) == @selectors.include?(line_item.variant.product.id)
  end

  def variant_id(line_item)
    (@match_type == :include) == @selectors.include?(line_item.variant.id)
  end

  def subscription(line_item)
    !line_item.selling_plan_id.nil?
  end

  def all(line_item)
    true
  end
end

# ================================================================
# DiscountApplicator
#
# Applies the entered discount to the supplied line item.
# ================================================================
class DiscountApplicator
  def initialize(discount_type, discount_amount, discount_message)
    @discount_type = discount_type
    @discount_message = discount_message

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

  def apply(line_item)
    new_line_price = if @discount_type == :percent
      line_item.line_price * @discount_amount
    else
      [line_item.line_price - (@discount_amount * line_item.quantity), Money.zero].max
    end

    line_item.change_line_price(new_line_price, message: @discount_message)
  end
end

# ================================================================
# DiscountLoop
#
# Loops through the supplied line items and discounts the supplied
# number of items by the supplied discount.
# ================================================================
class DiscountLoop
  def initialize(discount_applicator)
    @discount_applicator = discount_applicator
  end

  def loop_items(cart, line_items, num_to_discount)
    line_items.each_with_index do |line_item|
      break if num_to_discount <= 0

      if line_item.quantity > num_to_discount
        split_line_item = line_item.split(take: num_to_discount)
        @discount_applicator.apply(split_line_item)
        position = cart.line_items.find_index(line_item)
        cart.line_items.insert(position + 1, split_line_item)
        break
      else
        @discount_applicator.apply(line_item)
        num_to_discount -= line_item.quantity
      end
    end
  end
end

# ================================================================
# BundleDiscountCampaign
#
# If the entered bundle is present, the entered discount is
# applied to the entered product.
# ================================================================
class BundleDiscountCampaign
  def initialize(campaigns)
    @campaigns = campaigns
  end

  def run(cart)
    @campaigns.each do |campaign|
      bundle_selector = BundleSelector.new(campaign[:bundle_items])
      bundle_items = bundle_selector.build(cart)

      next if bundle_items.any? do |product_id, product_info|
        product_info[:total_quantity] < product_info[:quantity_needed]
      end

      num_bundles = bundle_items.map do |product_id, product_info|
        (product_info[:total_quantity] / product_info[:quantity_needed])
      end

      num_bundles = num_bundles.min.floor

      product_selector = ProductSelector.new(
        campaign[:discount_product_selector_match_type],
        campaign[:discount_product_selector_type],
        campaign[:discount_product_selectors],
      )

      discount_items = cart.line_items.select { |line_item| product_selector.match?(line_item) }

      next if discount_items.nil?

      discount_applicator = DiscountApplicator.new(
        campaign[:discount_type],
        campaign[:discount_amount],
        campaign[:discount_message]
      )

      discount_loop = DiscountLoop.new(discount_applicator)
      discount_loop.loop_items(cart, discount_items, (campaign[:quantity_to_discount] * num_bundles))
    end
  end
end

CAMPAIGNS = [
  BundleDiscountCampaign.new(BUNDLE_DISCOUNTS),
]

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

Output.cart = Input.cart

Bundle discount

Use this script to offer a discount when a specific set of products are added to the cart.

For example, offer customers 20% off the purchase of a t-shirt, a hat, and a pair of sunglasses.

# ================================ Customizable Settings ================================
# ================================================================
# Buy Products WXY, get Z Discount
#
# Buy a specific bundle of products, get that bundle at a
# discount. For example:
#
#   "Buy a t-shirt, a hat, and sunglasses, get 20% off each"
#
#   - 'bundle_items' is a list of the items that comprise the
#     bundle, where:
#     - 'product_id' is the ID of the product
#     - 'quantity_needed' is the quantity necessary to complete
#       the bundle
#   - 'discount_type' is the type of discount to provide. Can be
#     either:
#       - ':percent'
#       - ':dollar'
#   - 'discount_amount' is the percentage/dollar discount to
#     apply (per item)
#   - 'discount_message' is the message to show when a discount
#     is applied
# ================================================================
BUNDLE_DISCOUNTS = [
  {
    bundle_items: [
      {
        product_id: 1234567890987,
        quantity_needed: 1
      },
      {
        product_id: 1234567890986,
        quantity_needed: 1
      },
    ],
    discount_type: :percent,
    discount_amount: 10,
    discount_message: "Buy Product X and Product Y, get 10% off!",
  },
]

# ================================ Script Code (do not edit) ================================
# ================================================================
# BundleSelector
#
# Finds any items that are part of the entered bundle and saves
# them.
# ================================================================
class BundleSelector
  def initialize(bundle_items)
    @bundle_items = bundle_items.reduce({}) do |acc, bundle_item|
      acc[bundle_item[:product_id]] = {
        cart_items: [],
        quantity_needed: bundle_item[:quantity_needed],
        total_quantity: 0,
      }

      acc
    end
  end

  def build(cart)
    cart.line_items.each do |line_item|
            next if line_item.line_price_changed?
      next unless @bundle_items[line_item.variant.product.id]

      @bundle_items[line_item.variant.product.id][:cart_items].push(line_item)
      @bundle_items[line_item.variant.product.id][:total_quantity] += line_item.quantity
    end

    @bundle_items
  end
end

# ================================================================
# DiscountApplicator
#
# Applies the entered discount to the supplied line item.
# ================================================================
class DiscountApplicator
  def initialize(discount_type, discount_amount, discount_message)
    @discount_type = discount_type
    @discount_message = discount_message

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

  def apply(line_item)
    new_line_price = if @discount_type == :percent
      line_item.line_price * @discount_amount
    else
      [line_item.line_price - (@discount_amount * line_item.quantity), Money.zero].max
    end

    line_item.change_line_price(new_line_price, message: @discount_message)
  end
end

# ================================================================
# DiscountLoop
#
# Loops through the supplied line items and discounts the supplied
# number of items by the supplied discount.
# ================================================================
class DiscountLoop
  def initialize(discount_applicator)
    @discount_applicator = discount_applicator
  end

  def loop_items(cart, line_items, num_to_discount)
    line_items.each_with_index do |line_item|
      break if num_to_discount <= 0

      if line_item.quantity > num_to_discount
        split_line_item = line_item.split(take: num_to_discount)
        @discount_applicator.apply(split_line_item)
        position = cart.line_items.find_index(line_item)
        cart.line_items.insert(position + 1, split_line_item)
        break
      else
        @discount_applicator.apply(line_item)
        num_to_discount -= line_item.quantity
      end
    end
  end
end

# ================================================================
# BundleDiscountCampaign
#
# If the entered bundle is present, the entered discount is
# applied to each item in the bundle.
# ================================================================
class BundleDiscountCampaign
  def initialize(campaigns)
    @campaigns = campaigns
  end

  def run(cart)
    @campaigns.each do |campaign|
      bundle_selector = BundleSelector.new(campaign[:bundle_items])
      bundle_items = bundle_selector.build(cart)

      next if bundle_items.any? do |product_id, product_info|
        product_info[:total_quantity] < product_info[:quantity_needed]
      end

      num_bundles = bundle_items.map do |product_id, product_info|
        (product_info[:total_quantity] / product_info[:quantity_needed])
      end

      num_bundles = num_bundles.min.floor

      discount_applicator = DiscountApplicator.new(
        campaign[:discount_type],
        campaign[:discount_amount],
        campaign[:discount_message]
      )

      discount_loop = DiscountLoop.new(discount_applicator)

      bundle_items.each do |product_id, product_info|
        discount_loop.loop_items(
          cart,
          product_info[:cart_items],
          (product_info[:quantity_needed] * num_bundles),
        )
      end
    end
  end
end

CAMPAIGNS = [
  BundleDiscountCampaign.new(BUNDLE_DISCOUNTS),
]

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

Output.cart = Input.cart

Buy one get one (BOGO) discount

Use this script to offer a percentage discount on an item when a customer purchases a set number of a different product.

For example, offer customers a hat for 10% off if they purchase 2 t-shirts.

Note

This script will not add the 'get' item(s) to the cart. It can only discount items that are already in the cart.

# ================================ Customizable Settings ================================
# ================================================================
# Buy V of Product W, Get X of Product Y for Z Discount
#
# Buy a certain number of matching items, get a certain number of
# a different set of matching items with the entered discount
# applied. For example:
#
#   "Buy 2 t-shirts, get 1 hat for 10% off"
#
#   - 'buy_product_selector_match_type' determines whether we look
#     for products that do or don't match the entered selectors.
#     Can be:
#       - ':include' to check if the product does match
#       - ':exclude' to make sure the product doesn't match
#   - 'buy_product_selector_type' determines how eligible products
#     will be identified. Can be:
#       - ':tag' to find products by tag
#       - ':type' to find products by type
#       - ':vendor' to find products by vendor
#       - ':product_id' to find products by ID
#       - ':variant_id' to find products by variant ID
#       - ':subscription' to find subscription products
#       - ':all' for all products
#   - 'buy_product_selectors' is a list of identifiers (from above)
#     for qualifying products. Product/Variant ID lists should only
#     contain numbers (ie. no quotes). If ':all' is used, this
#     can also be 'nil'.
#   - 'quantity_to_buy' is the number of products needed to
#     qualify
#   - 'get_selector_match_type' is the same idea as the "Buy"
#     version above
#   - 'get_product_selector_type' is the same idea as the "Buy"
#     version above
#   - 'get_product_selectors' is the same idea as the "Buy"
#     version above
#   - 'quantity_to_discount' is the number of products to discount
#   - 'allow_incomplete_bundle' determines whether a portion of
#     the items to discount can be discounted, or all items
#     need to be present. Can be:
#       - 'true'
#       - 'false'
#   - 'discount_type' is the type of discount to provide. Can be
#     either:
#       - ':percent'
#       - ':dollar'
#   - 'discount_amount' is the percentage/dollar discount to
#     apply (per item)
#   - 'discount_message' is the message to show when a discount
#     is applied
# ================================================================
BUYVOFW_GETXOFY_FORZ = [
  {
    buy_product_selector_match_type: :include,
    buy_product_selector_type: :tag,
    buy_product_selectors: ["your_tag", "another_tag"],
    quantity_to_buy: 1,
    get_product_selector_match_type: :include,
    get_product_selector_type: :tag,
    get_product_selectors: ["your_other_tag", "a_different_tag"],
    quantity_to_discount: 1,
    allow_incomplete_bundle: false,
    discount_type: :percent,
    discount_amount: 100,
    discount_message: 'Buy a Product X, get a Product Y free!',
  },
  {
    buy_product_selector_match_type: :include,
    buy_product_selector_type: :product_id,
    buy_product_selectors: [1234567890987, 1234567890986],
    quantity_to_buy: 1,
    get_product_selector_match_type: :include,
    get_product_selector_type: :product_id,
    get_product_selectors: [1234567890985, 1234567890984],
    quantity_to_discount: 1,
    allow_incomplete_bundle: false,
    discount_type: :dollar,
    discount_amount: 10,
    discount_message: 'Buy a Product X, get $10 off a Product Y!',
  },
]

# ================================ Script Code (do not edit) ================================
# ================================================================
# ProductSelector
#
# Finds matching products by the entered criteria.
# ================================================================
class ProductSelector
  def initialize(match_type, selector_type, selectors)
    @match_type = match_type
    @comparator = match_type == :include ? 'any?' : 'none?'
    @selector_type = selector_type
    @selectors = selectors
  end

  def match?(line_item)
    if self.respond_to?(@selector_type)
      self.send(@selector_type, line_item)
    else
      raise RuntimeError.new('Invalid product selector type')
    end
  end

  def tag(line_item)
    product_tags = line_item.variant.product.tags.map { |tag| tag.downcase.strip }
    @selectors = @selectors.map { |selector| selector.downcase.strip }
    (@selectors & product_tags).send(@comparator)
  end

  def type(line_item)
    @selectors = @selectors.map { |selector| selector.downcase.strip }
    (@match_type == :include) == @selectors.include?(line_item.variant.product.product_type.downcase.strip)
  end

  def vendor(line_item)
    @selectors = @selectors.map { |selector| selector.downcase.strip }
    (@match_type == :include) == @selectors.include?(line_item.variant.product.vendor.downcase.strip)
  end

  def product_id(line_item)
    (@match_type == :include) == @selectors.include?(line_item.variant.product.id)
  end

  def variant_id(line_item)
    (@match_type == :include) == @selectors.include?(line_item.variant.id)
  end

  def subscription(line_item)
    !line_item.selling_plan_id.nil?
  end

  def all(line_item)
    true
  end
end

# ================================================================
# DiscountApplicator
#
# Applies the entered discount to the supplied line item.
# ================================================================
class DiscountApplicator
  def initialize(discount_type, discount_amount, discount_message)
    @discount_type = discount_type
    @discount_message = discount_message

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

  def apply(line_item)
    new_line_price = if @discount_type == :percent
      line_item.line_price * @discount_amount
    else
      [line_item.line_price - (@discount_amount * line_item.quantity), Money.zero].max
    end

    line_item.change_line_price(new_line_price, message: @discount_message)
  end
end

# ================================================================
# DiscountLoop
#
# Loops through the supplied line items and discounts the supplied
# number of items by the supplied discount.
# ================================================================
class DiscountLoop
  def initialize(discount_applicator)
    @discount_applicator = discount_applicator
  end

  def loop_items(cart, line_items, num_to_discount)
    line_items.each do |line_item|
      break if num_to_discount <= 0

      if line_item.quantity > num_to_discount
        split_line_item = line_item.split(take: num_to_discount)
        @discount_applicator.apply(split_line_item)
        position = cart.line_items.find_index(line_item)
        cart.line_items.insert(position + 1, split_line_item)
        break
      else
        @discount_applicator.apply(line_item)
        num_to_discount -= line_item.quantity
      end
    end
  end
end

# ================================================================
# BuyVofWGetXofYForZCampaign
#
# Buy a certain number of matching items, get a certain number of
# a different set of matching items with the entered discount
# applied.
# ================================================================
class BuyVofWGetXofYForZCampaign
  def initialize(campaigns)
    @campaigns = campaigns
  end

  def run(cart)
    @campaigns.each do |campaign|
      buy_product_selector = ProductSelector.new(
        campaign[:buy_product_selector_match_type],
        campaign[:buy_product_selector_type],
        campaign[:buy_product_selectors],
      )

      get_product_selector = ProductSelector.new(
        campaign[:get_product_selector_match_type],
        campaign[:get_product_selector_type],
        campaign[:get_product_selectors],
      )

      buy_items = []
      get_items = []

      cart.line_items.each do |line_item|
        buy_items.push(line_item) if buy_product_selector.match?(line_item)
        get_items.push(line_item) if get_product_selector.match?(line_item)
      end

      next if buy_items.empty? || get_items.empty?

      get_items = get_items.sort_by { |line_item| line_item.variant.price }
      quantity_to_buy = campaign[:quantity_to_buy]
      quantity_to_discount = campaign[:quantity_to_discount]
      buy_offers = (buy_items.map(&:quantity).reduce(0, :+) / quantity_to_buy).floor

      if campaign[:allow_incomplete_bundle]
        number_of_bundles = buy_offers
      else
        get_offers = (get_items.map(&:quantity).reduce(0, :+) / quantity_to_discount).floor
        number_of_bundles = [buy_offers, get_offers].min
      end

      number_of_discountable_items = number_of_bundles * quantity_to_discount

      next unless number_of_discountable_items > 0

      discount_applicator = DiscountApplicator.new(
        campaign[:discount_type],
        campaign[:discount_amount],
        campaign[:discount_message]
      )

      discount_loop = DiscountLoop.new(discount_applicator)
      discount_loop.loop_items(cart, get_items, number_of_discountable_items)
    end
  end
end

CAMPAIGNS = [
  BuyVofWGetXofYForZCampaign.new(BUYVOFW_GETXOFY_FORZ),
]

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

Output.cart = Input.cart

Buy a specific quantity of a product for a specific amount

Use this script to offer a number of products for a chosen price.

For example, offer customers 2 t-shirts for $20.

# ================================ Customizable Settings ================================
# ================================================================
# Buy X of Product Y for $Z
#
# Buy a certain number of matching items for a specific price.
# For example:
#
#   "Buy 2 t-shirts for $20"
#
#   - 'product_selector_match_type' determines whether we look for
#     products that do or don't match the entered selectors. Can
#     be:
#       - ':include' to check if the product does match
#       - ':exclude' to make sure the product doesn't match
#   - 'product_selector_type' determines how eligible products
#     will be identified. Can be either:
#       - ':tag' to find products by tag
#       - ':type' to find products by type
#       - ':vendor' to find products by vendor
#       - ':product_id' to find products by ID
#       - ':variant_id' to find products by variant ID
#       - ':subscription' to find subscription products
#       - ':all' for all products
#   - 'product_selectors' is a list of identifiers (from above)
#     for qualifying products. Product/Variant ID lists should
#     only contain numbers (ie. no quotes). If ':all' is used,
#     this can also be 'nil'.
#   - 'quantity_to_buy' is the number of products needed to
#     qualify
#   - 'final_price` is the amount to charge for all products that
#     are part of the offer
#   - 'discount_message' is the message to show when a discount
#     is applied
# ================================================================
BUY_X_GET_Y_FOR_Z = [
  {
    product_selector_match_type: :include,
    product_selector_type: :tag,
    product_selectors: ["your_tag"],
    quantity_to_buy: 2,
    final_price: 100,
    discount_message: 'Buy 2 for $20',
  },
]

# ================================ Script Code (do not edit) ================================
# ================================================================
# ProductSelector
#
# Finds matching products by the entered criteria.
# ================================================================
class ProductSelector
  def initialize(match_type, selector_type, selectors)
    @match_type = match_type
    @comparator = match_type == :include ? 'any?' : 'none?'
    @selector_type = selector_type
    @selectors = selectors
  end

  def match?(line_item)
    if self.respond_to?(@selector_type)
      self.send(@selector_type, line_item)
    else
      raise RuntimeError.new('Invalid product selector type')
    end
  end

  def tag(line_item)
    product_tags = line_item.variant.product.tags.map { |tag| tag.downcase.strip }
    @selectors = @selectors.map { |selector| selector.downcase.strip }
    (@selectors & product_tags).send(@comparator)
  end

  def type(line_item)
    @selectors = @selectors.map { |selector| selector.downcase.strip }
    (@match_type == :include) == @selectors.include?(line_item.variant.product.product_type.downcase.strip)
  end

  def vendor(line_item)
    @selectors = @selectors.map { |selector| selector.downcase.strip }
    (@match_type == :include) == @selectors.include?(line_item.variant.product.vendor.downcase.strip)
  end

  def product_id(line_item)
    (@match_type == :include) == @selectors.include?(line_item.variant.product.id)
  end

  def variant_id(line_item)
    (@match_type == :include) == @selectors.include?(line_item.variant.id)
  end

  def subscription(line_item)
    !line_item.selling_plan_id.nil?
  end

  def all(line_item)
    true
  end
end

# ================================================================
# DollarDiscountApplicator
#
# Applies the entered discount to the supplied line item.
# ================================================================
class DollarDiscountApplicator
  def initialize(discount_message)
    @discount_message = discount_message
  end

  def apply(line_item, discount_amount)
    new_line_price = line_item.line_price - discount_amount
    line_item.change_line_price(new_line_price, message: @discount_message)
  end
end

# ================================================================
# BuyXOfYForZCampaign
#
# Buy a certain number of matching items for a specific price.
# ================================================================
class BuyXOfYForZCampaign
  def initialize(campaigns)
    @campaigns = campaigns
  end

  def run(cart)
    @campaigns.each do |campaign|
      product_selector = ProductSelector.new(
        campaign[:product_selector_match_type],
        campaign[:product_selector_type],
        campaign[:product_selectors],
      )

      eligible_items = cart.line_items.select { |line_item| product_selector.match?(line_item) }

      next if eligible_items.nil?

      eligible_item_count = eligible_items.map(&:quantity).reduce(0, :+)
      quantity_to_buy = campaign[:quantity_to_buy]
      number_of_offers = (eligible_item_count / quantity_to_buy).floor

      next unless number_of_offers > 0

      number_of_discountable_items = number_of_offers * quantity_to_buy
      total_offer_price = Money.new(cents: 100) * (number_of_offers * campaign[:final_price])
      discount_applicator = DollarDiscountApplicator.new(campaign[:discount_message])

      self.loop_items(cart, eligible_items, number_of_discountable_items, total_offer_price, discount_applicator)
    end
  end

  def loop_items(cart, line_items, num_to_discount, total_price, discount_applicator)
    current_price = Money.zero
    avg_price = total_price * (1 / num_to_discount)

    line_items = line_items.sort_by { |line_item| line_item.variant.price }

    line_items.each do |line_item|
      break if num_to_discount <= 0

      if line_item.quantity > num_to_discount
        split_line_item = line_item.split(take: num_to_discount)
        discount_amount = split_line_item.line_price - (total_price - current_price)
        discount_applicator.apply(split_line_item, discount_amount)
        position = cart.line_items.find_index(line_item)
        cart.line_items.insert(position + 1, split_line_item)
        break
      elsif line_item.quantity == num_to_discount
        discount_amount = line_item.line_price - (total_price - current_price)
        discount_applicator.apply(line_item, discount_amount)
        break
      else
        if line_item.variant.price <= avg_price
          current_price += line_item.line_price
        else
          discount_amount = (line_item.variant.price - avg_price) * line_item.quantity
          current_price += (line_item.line_price - discount_amount)
          discount_applicator.apply(line_item, discount_amount)
        end

        num_to_discount -= line_item.quantity
      end
    end
  end
end

CAMPAIGNS = [
  BuyXOfYForZCampaign.new(BUY_X_GET_Y_FOR_Z),
]

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

Output.cart = Input.cart

Free gift with purchase

Use this script to offer a discount on a specific product if the cart total is greater than a certain amount.

For example, offer customers a free gift if they spend more than $75.

Note

This script will not add the 'get' item(s) to the cart. It can only discount items that are already in the cart.

# ================================ Customizable Settings ================================
# ================================================================
# Spend $X, get Product Y for Z Discount
#
# If the cart total is greater than (or equal to) the entered
# threshold (less the discounted amount), the entered number of
# matching items is discounted by the entered amount.
#
#   - 'product_selector_match_type' determines whether we look for
#     products that do or don't match the entered selectors. Can
#     be:
#       - ':include' to check if the product does match
#       - ':exclude' to make sure the product doesn't match
#   - 'product_selector_type' determines how eligible products
#     will be identified. Can be either:
#       - ':tag' to find products by tag
#       - ':type' to find products by type
#       - ':vendor' to find products by vendor
#       - ':product_id' to find products by ID
#       - ':variant_id' to find products by variant ID
#       - ':subscription' to find subscription products
#       - ':all' for all products
#   - 'product_selectors' is a list of identifiers (from above)
#     for qualifying products. Product/Variant ID lists should
#     only contain numbers (ie. no quotes). If ':all' is used,
#     this can also be 'nil'.
#   - 'threshold' is the dollar amount needed to spend to qualify
#   - 'quantity_to_discount' is the number of items to discount
#     if qualified
#   - 'discount_type' is the type of discount to provide. Can be
#     either:
#       - ':percent'
#       - ':dollar'
#   - 'discount_amount' is the percentage/dollar discount to
#     apply (per item)
#   - 'discount_message' is the message to show when a discount
#     is applied
# ================================================================
SPENDX_GETY_FORZ = [
  {
    product_selector_match_type: :include,
    product_selector_type: :product_id,
    product_selectors: [1234567890123],
    threshold: 75,
    quantity_to_discount: 1,
    discount_type: :percent,
    discount_amount: 100,
    discount_message: 'Spend $75 or more and get a free Product X!',
  },
]

# ================================ Script Code (do not edit) ================================
# ================================================================
# ProductSelector
#
# Finds matching products by the entered criteria.
# ================================================================
class ProductSelector
  def initialize(match_type, selector_type, selectors)
    @match_type = match_type
    @comparator = match_type == :include ? 'any?' : 'none?'
    @selector_type = selector_type
    @selectors = selectors
  end

  def match?(line_item)
    if self.respond_to?(@selector_type)
      self.send(@selector_type, line_item)
    else
      raise RuntimeError.new('Invalid product selector type')
    end
  end

  def tag(line_item)
    product_tags = line_item.variant.product.tags.map { |tag| tag.downcase.strip }
    @selectors = @selectors.map { |selector| selector.downcase.strip }
    (@selectors & product_tags).send(@comparator)
  end

  def type(line_item)
    @selectors = @selectors.map { |selector| selector.downcase.strip }
    (@match_type == :include) == @selectors.include?(line_item.variant.product.product_type.downcase.strip)
  end

  def vendor(line_item)
    @selectors = @selectors.map { |selector| selector.downcase.strip }
    (@match_type == :include) == @selectors.include?(line_item.variant.product.vendor.downcase.strip)
  end

  def product_id(line_item)
    (@match_type == :include) == @selectors.include?(line_item.variant.product.id)
  end

  def variant_id(line_item)
    (@match_type == :include) == @selectors.include?(line_item.variant.id)
  end

  def subscription(line_item)
    !line_item.selling_plan_id.nil?
  end

  def all(line_item)
    true
  end
end

# ================================================================
# DiscountApplicator
#
# Applies the entered discount to the supplied line item.
# ================================================================
class DiscountApplicator
  def initialize(discount_type, discount_amount, discount_message)
    @discount_type = discount_type
    @discount_message = discount_message

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

  def apply(line_item)
    new_line_price = if @discount_type == :percent
      line_item.line_price * @discount_amount
    else
      [line_item.line_price - (@discount_amount * line_item.quantity), Money.zero].max
    end

    line_item.change_line_price(new_line_price, message: @discount_message)
  end
end

# ================================================================
# DiscountLoop
#
# Loops through the supplied line items and discounts the supplied
# number of items by the supplied discount.
# ================================================================
class DiscountLoop
  def initialize(discount_applicator)
    @discount_applicator = discount_applicator
  end

  def loop_items(cart, line_items, num_to_discount)
    line_items.each do |line_item|
      break if num_to_discount <= 0

      if line_item.quantity > num_to_discount
        split_line_item = line_item.split(take: num_to_discount)
        @discount_applicator.apply(split_line_item)
        position = cart.line_items.find_index(line_item)
        cart.line_items.insert(position + 1, split_line_item)
        break
      else
        @discount_applicator.apply(line_item)
        num_to_discount -= line_item.quantity
      end
    end
  end
end

# ================================================================
# SpendXGetYForZCampaign
#
# If the cart total is greater than (or equal to) the entered
# threshold (less the discounted amount), the entered number of
# matching items is discounted by the entered amount.
# ================================================================
class SpendXGetYForZCampaign
  def initialize(campaigns)
    @campaigns = campaigns
  end

  def run(cart)
    @campaigns.each do |campaign|
      threshold = Money.new(cents: 100) * campaign[:threshold]

      next if cart.subtotal_price < threshold

      product_selector = ProductSelector.new(
        campaign[:product_selector_match_type],
        campaign[:product_selector_type],
        campaign[:product_selectors],
      )

      eligible_items = cart.line_items.select { |line_item| product_selector.match?(line_item) }

      next if eligible_items.nil?

      eligible_items = eligible_items.sort_by { |line_item| line_item.variant.price }
      num_to_discount = campaign[:quantity_to_discount]
      cart_total = cart.subtotal_price

      eligible_items.each do |line_item|
        break if num_to_discount <= 0

        if line_item.quantity > num_to_discount
          cart_total -= line_item.variant.price * num_to_discount
          break
        else
          cart_total -= line_item.line_price
          num_to_discount -= line_item.quantity
        end
      end

      next if cart_total < threshold

      discount_applicator = discount_applicator = DiscountApplicator.new(
        campaign[:discount_type],
        campaign[:discount_amount],
        campaign[:discount_message]
      )

      discount_loop = DiscountLoop.new(discount_applicator)
      discount_loop.loop_items(cart, eligible_items, campaign[:quantity_to_discount])
    end
  end
end

CAMPAIGNS = [
  SpendXGetYForZCampaign.new(SPENDX_GETY_FORZ),
]

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

Output.cart = Input.cart

Product discount by customer tag

Use this script to offer a discount on specific products to customers with specific tags.

For example, offer a 20% discount if the customer has the VIP tag.

# ================================ Customizable Settings ================================
# ================================================================
# Product Discounts by Customer Tag
#
# If we have a matching customer (by tag), the entered discount
# will be applied to any matching items.
#
#   - 'customer_tag_match_type' determines whether we look for the customer
#     to be tagged with any of the entered tags or not. Can be:
#       - ':include' to check if the customer is tagged
#       - ':exclude' to make sure the customer isn't tagged
#   - 'customer_tags' is a list of tags to identify qualified
#     customers
#   - 'product_selector_match_type' determines whether we look for
#     products that do or don't match the entered selectors. Can
#     be:
#       - ':include' to check if the product does match
#       - ':exclude' to make sure the product doesn't match
#   - 'product_selector_type' determines how eligible products
#     will be identified. Can be either:
#       - ':tag' to find products by tag
#       - ':type' to find products by type
#       - ':vendor' to find products by vendor
#       - ':product_id' to find products by ID
#       - ':variant_id' to find products by variant ID
#       - ':subscription' to find subscription products
#       - ':all' for all products
#   - 'product_selectors' is a list of identifiers (from above)
#     for qualifying products. Product/Variant ID lists should
#     only contain numbers (ie. no quotes). If ':all' is used,
#     this can also be 'nil'.
#   - 'discount_type' is the type of discount to provide. Can be
#     either:
#       - ':percent'
#       - ':dollar'
#   - 'discount_amount' is the percentage/dollar discount to
#     apply (per item)
#   - 'discount_message' is the message to show when a discount
#     is applied
# ================================================================
DISCOUNTS_FOR_CUSTOMER_TAG = [
  {
    customer_tag_match_type: :include,
    customer_tags: ["VIP"],
    product_selector_match_type: :include,
    product_selector_type: :all,
    product_selectors: nil,
    discount_type: :percent,
    discount_amount: 20,
    discount_message: "Discount for VIP customers!",
  },
]

# ================================ Script Code (do not edit) ================================
# ================================================================
# CustomerTagSelector
#
# Finds whether the supplied customer has any of the entered tags.
# ================================================================
class CustomerTagSelector
  def initialize(match_type, tags)
    @comparator = match_type == :include ? 'any?' : 'none?'
    @tags = tags.map { |tag| tag.downcase.strip }
  end

  def match?(customer)
    customer_tags = customer.tags.map { |tag| tag.downcase.strip }
    (@tags & customer_tags).send(@comparator)
  end
end

# ================================================================
# ProductSelector
#
# Finds matching products by the entered criteria.
# ================================================================
class ProductSelector
  def initialize(match_type, selector_type, selectors)
    @match_type = match_type
    @comparator = match_type == :include ? 'any?' : 'none?'
    @selector_type = selector_type
    @selectors = selectors
  end

  def match?(line_item)
    if self.respond_to?(@selector_type)
      self.send(@selector_type, line_item)
    else
      raise RuntimeError.new('Invalid product selector type')
    end
  end

  def tag(line_item)
    product_tags = line_item.variant.product.tags.map { |tag| tag.downcase.strip }
    @selectors = @selectors.map { |selector| selector.downcase.strip }
    (@selectors & product_tags).send(@comparator)
  end

  def type(line_item)
    @selectors = @selectors.map { |selector| selector.downcase.strip }
    (@match_type == :include) == @selectors.include?(line_item.variant.product.product_type.downcase.strip)
  end

  def vendor(line_item)
    @selectors = @selectors.map { |selector| selector.downcase.strip }
    (@match_type == :include) == @selectors.include?(line_item.variant.product.vendor.downcase.strip)
  end

  def product_id(line_item)
    (@match_type == :include) == @selectors.include?(line_item.variant.product.id)
  end

  def variant_id(line_item)
    (@match_type == :include) == @selectors.include?(line_item.variant.id)
  end

  def subscription(line_item)
    !line_item.selling_plan_id.nil?
  end

  def all(line_item)
    true
  end
end

# ================================================================
# DiscountApplicator
#
# Applies the entered discount to the supplied line item.
# ================================================================
class DiscountApplicator
  def initialize(discount_type, discount_amount, discount_message)
    @discount_type = discount_type
    @discount_message = discount_message

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

  def apply(line_item)
    new_line_price = if @discount_type == :percent
      line_item.line_price * @discount_amount
    else
      [line_item.line_price - (@discount_amount * line_item.quantity), Money.zero].max
    end

    line_item.change_line_price(new_line_price, message: @discount_message)
  end
end

# ================================================================
# DiscountForCustomerTagCampaign
#
# If we have a matching customer (by tag), the entered discount
# is applied to any matching items.
# ================================================================
class DiscountForCustomerTagCampaign
  def initialize(campaigns)
    @campaigns = campaigns
  end

  def run(cart)
    return unless cart.customer&.tags

    @campaigns.each do |campaign|
      customer_tag_selector = CustomerTagSelector.new(campaign[:customer_tag_match_type], campaign[:customer_tags])

      next unless customer_tag_selector.match?(cart.customer)

      product_selector = ProductSelector.new(
        campaign[:product_selector_match_type],
        campaign[:product_selector_type],
        campaign[:product_selectors]
      )

      discount_applicator = DiscountApplicator.new(
        campaign[:discount_type],
        campaign[:discount_amount],
        campaign[:discount_message]
      )

      cart.line_items.each do |line_item|
        next unless product_selector.match?(line_item)
        discount_applicator.apply(line_item)
      end
    end
  end
end

CAMPAIGNS = [
  DiscountForCustomerTagCampaign.new(DISCOUNTS_FOR_CUSTOMER_TAG),
]

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

Output.cart = Input.cart

Product discount by customer marketing

Use this script to offer a discount on specific products to customers who accept marketing.

For example, offer 10% off all products for any customers that accept marketing.

# ================================ Customizable Settings ================================
# ================================================================
# Product Discount by Customer Marketing
#
# If the customer accepts marketing, any matching  items are
# discounted by the entered amount.
#
#   - 'product_selector_match_type' determines whether we look for
#     products that do or don't match the entered selectors. Can
#     be:
#       - ':include' to check if the product does match
#       - ':exclude' to make sure the product doesn't match
#   - 'product_selector_type' determines how eligible products
#     will be identified. Can be either:
#       - ':tag' to find products by tag
#       - ':type' to find products by type
#       - ':vendor' to find products by vendor
#       - ':product_id' to find products by ID
#       - ':variant_id' to find products by variant ID
#       - ':subscription' to find subscription products
#       - ':all' for all products
#   - 'product_selectors' is a list of identifiers (from above)
#     for qualifying products. Product/Variant ID lists should
#     only contain numbers (ie. no quotes). If ':all' is used,
#     this can also be 'nil'.
#   - 'discount_type' is the type of discount to provide. Can be
#     either:
#       - ':percent'
#       - ':dollar'
#   - 'discount_amount' is the percentage/dollar discount to
#     apply (per item)
#   - 'discount_message' is the message to show when a discount
#     is applied
# ================================================================
PRODUCT_DISCOUNTS_BY_CUSTOMER_MARKETING = [
  {
    product_selector_match_type: :include,
    product_selector_type: :all,
    product_selectors: nil,
    discount_type: :percent,
    discount_amount: 10,
    discount_message: '10% off for subscribed customers!'
  }
]

# ================================ Script Code (do not edit) ===============================
# ================================================================
# ProductSelector
#
# Finds matching products by the entered criteria.
# ================================================================
class ProductSelector
  def initialize(match_type, selector_type, selectors)
    @match_type = match_type
    @comparator = match_type == :include ? 'any?' : 'none?'
    @selector_type = selector_type
    @selectors = selectors
  end

  def match?(line_item)
    if self.respond_to?(@selector_type)
      self.send(@selector_type, line_item)
    else
      raise RuntimeError.new('Invalid product selector type')
    end
  end

  def tag(line_item)
    product_tags = line_item.variant.product.tags.map { |tag| tag.downcase.strip }
    @selectors = @selectors.map { |selector| selector.downcase.strip }
    (@selectors & product_tags).send(@comparator)
  end

  def type(line_item)
    @selectors = @selectors.map { |selector| selector.downcase.strip }
    (@match_type == :include) == @selectors.include?(line_item.variant.product.product_type.downcase.strip)
  end

  def vendor(line_item)
    @selectors = @selectors.map { |selector| selector.downcase.strip }
    (@match_type == :include) == @selectors.include?(line_item.variant.product.vendor.downcase.strip)
  end

  def product_id(line_item)
    (@match_type == :include) == @selectors.include?(line_item.variant.product.id)
  end

  def variant_id(line_item)
    (@match_type == :include) == @selectors.include?(line_item.variant.id)
  end

  def subscription(line_item)
    !line_item.selling_plan_id.nil?
  end

  def all(line_item)
    true
  end
end

# ================================================================
# DiscountApplicator
#
# Applies the entered discount to the supplied line item.
# ================================================================
class DiscountApplicator
  def initialize(discount_type, discount_amount, discount_message)
    @discount_type = discount_type
    @discount_message = discount_message

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

  def apply(line_item)
    new_line_price = if @discount_type == :percent
      line_item.line_price * @discount_amount
    else
      [line_item.line_price - (@discount_amount * line_item.quantity), Money.zero].max
    end

    line_item.change_line_price(new_line_price, message: @discount_message)
  end
end

# ================================================================
# ProductDiscountByCustomerMarketingCampaign
#
# If the customer accepts marketing, any matching items are
# discounted by the entered amount.
# ================================================================
class ProductDiscountByCustomerMarketingCampaign
  def initialize(campaigns)
    @campaigns = campaigns
  end

  def run(cart)
    return if cart.customer.nil?

    @campaigns.each do |campaign|
      next unless cart.customer.accepts_marketing?

      product_selector = ProductSelector.new(
        campaign[:product_selector_match_type],
        campaign[:product_selector_type],
        campaign[:product_selectors]
      )

      discount_applicator = DiscountApplicator.new(
        campaign[:discount_type],
        campaign[:discount_amount],
        campaign[:discount_message]
      )

      cart.line_items.each do |line_item|
        next unless product_selector.match?(line_item)
        discount_applicator.apply(line_item)
      end
    end
  end
end

CAMPAIGNS = [
  ProductDiscountByCustomerMarketingCampaign.new(PRODUCT_DISCOUNTS_BY_CUSTOMER_MARKETING),
]

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

Output.cart = Input.cart

Product discount by customer order count

Use this script to offer a discount on specific products for customers with a specific order count.

For example, offer 10% off for any customer with no orders.

# ================================ Customizable Settings ================================
# ================================================================
# Product Discount by Order Count
#
# If the customer has made a matching number of orders, any
# matching items are discounted by the entered amount.
#
#   - 'order_count_match_type' determines how we compare the
#     customer's order count to the entered limit. Can be:
#       - ':greater_than' to ensure that the customer's order count
#         is greater than the entered limit
#       - ':greater_than_equal' to ensure that the customer's order
#         count is greater than, or equal to, the entered limit
#       - ':less_than' to ensure that the customer's order count is
#         less than the entered limit
#       - ':less_than_equal' to ensure that the customer's order
#         count is less than, or equal to, the entered limit
#   - 'product_selector_match_type' determines whether we look for
#     products that do or don't match the entered selectors. Can
#     be:
#       - ':include' to check if the product does match
#       - ':exclude' to make sure the product doesn't match
#   - 'product_selector_type' determines how eligible products
#     will be identified. Can be either:
#       - ':tag' to find products by tag
#       - ':type' to find products by type
#       - ':vendor' to find products by vendor
#       - ':product_id' to find products by ID
#       - ':variant_id' to find products by variant ID
#       - ':subscription' to find subscription products
#       - ':all' for all products
#   - 'product_selectors' is a list of identifiers (from above)
#     for qualifying products. Product/Variant ID lists should
#     only contain numbers (ie. no quotes). If ':all' is used,
#     this can also be 'nil'.
#   - 'discount_type' is the type of discount to provide. Can be
#     either:
#       - ':percent'
#       - ':dollar'
#   - 'discount_amount' is the percentage/dollar discount to
#     apply (per item)
#   - 'discount_message' is the message to show when a discount
#     is applied
# ================================================================
PRODUCT_DISCOUNTS_BY_ORDER_COUNT = [
  {
    order_count_match_type: :less_than,
    order_count_limit: 1,
    product_selector_match_type: :include,
    product_selector_type: :all,
    product_selectors: nil,
    discount_type: :percent,
    discount_amount: 10,
    discount_message: '10% off for first time customers!'
  }
]

# ================================ Script Code (do not edit) ===============================
# ================================================================
# OrderCountSelector
#
# Finds whether the customer has made a certain number of orders
# ================================================================
class OrderCountSelector
  def initialize(match_type, limit)
    @match_type = match_type
    @limit = limit
  end

  def match?(customer)
    if self.respond_to?(@match_type)
      self.send(@match_type, customer, @limit)
    else
      raise RuntimeError.new('Invalid order count match type')
    end
  end

  def greater_than(customer, limit)
    customer.orders_count > limit
  end

  def greater_than_equal(customer, limit)
    customer.orders_count >= limit
  end

  def less_than(customer, limit)
    customer.orders_count < limit
  end

  def less_than_equal(customer, limit)
    customer.orders_count <= limit
  end
end

# ================================================================
# ProductSelector
#
# Finds matching products by the entered criteria.
# ================================================================
class ProductSelector
  def initialize(match_type, selector_type, selectors)
    @match_type = match_type
    @comparator = match_type == :include ? 'any?' : 'none?'
    @selector_type = selector_type
    @selectors = selectors
  end

  def match?(line_item)
    if self.respond_to?(@selector_type)
      self.send(@selector_type, line_item)
    else
      raise RuntimeError.new('Invalid product selector type')
    end
  end

  def tag(line_item)
    product_tags = line_item.variant.product.tags.map { |tag| tag.downcase.strip }
    @selectors = @selectors.map { |selector| selector.downcase.strip }
    (@selectors & product_tags).send(@comparator)
  end

  def type(line_item)
    @selectors = @selectors.map { |selector| selector.downcase.strip }
    (@match_type == :include) == @selectors.include?(line_item.variant.product.product_type.downcase.strip)
  end

  def vendor(line_item)
    @selectors = @selectors.map { |selector| selector.downcase.strip }
    (@match_type == :include) == @selectors.include?(line_item.variant.product.vendor.downcase.strip)
  end

  def product_id(line_item)
    (@match_type == :include) == @selectors.include?(line_item.variant.product.id)
  end

  def variant_id(line_item)
    (@match_type == :include) == @selectors.include?(line_item.variant.id)
  end

  def subscription(line_item)
    !line_item.selling_plan_id.nil?
  end

  def all(line_item)
    true
  end
end

# ================================================================
# DiscountApplicator
#
# Applies the entered discount to the supplied line item.
# ================================================================
class DiscountApplicator
  def initialize(discount_type, discount_amount, discount_message)
    @discount_type = discount_type
    @discount_message = discount_message

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

  def apply(line_item)
    new_line_price = if @discount_type == :percent
      line_item.line_price * @discount_amount
    else
      [line_item.line_price - (@discount_amount * line_item.quantity), Money.zero].max
    end

    line_item.change_line_price(new_line_price, message: @discount_message)
  end
end

# ================================================================
# ProductDiscountByOrderCountCampaign
#
# If the customer has made a matching number of orders, any
# matching items are discounted by the entered amount.
# ================================================================
class ProductDiscountByOrderCountCampaign
  def initialize(campaigns)
    @campaigns = campaigns
  end

  def run(cart)
    return if cart.customer.nil?

    @campaigns.each do |campaign|
      order_count_selector = OrderCountSelector.new(
        campaign[:order_count_match_type],
        campaign[:order_count_limit]
      )

      next unless order_count_selector.match?(cart.customer)

      product_selector = ProductSelector.new(
        campaign[:product_selector_match_type],
        campaign[:product_selector_type],
        campaign[:product_selectors]
      )

      discount_applicator = DiscountApplicator.new(
        campaign[:discount_type],
        campaign[:discount_amount],
        campaign[:discount_message]
      )

      cart.line_items.each do |line_item|
        next unless product_selector.match?(line_item)
        discount_applicator.apply(line_item)
      end
    end
  end
end

CAMPAIGNS = [
  ProductDiscountByOrderCountCampaign.new(PRODUCT_DISCOUNTS_BY_ORDER_COUNT),
]

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

Output.cart = Input.cart

Disable discount codes

Use this script to disable use of discount codes in the checkout process.

For example, prevent customers from using discount codes while your store is offering a sale.

# ================================ Customizable Settings ================================
# ================================================================
# Disable Discount Code Use
#
# Any discount codes will be rejected with the entered message.
#
#   - 'REJECTION_MESSAGE' is the message to show when a discount
#     code is rejected
# ================================================================
REJECTION_MESSAGE = 'Discount codes cannot be used during this sale'

# ================================ Script Code (do not edit) ================================
# ================================================================
# DisableDiscountCodesCampaign
#
# Any discount codes will be rejected with the entered message.
# ================================================================
class DisableDiscountCodesCampaign
  def initialize(rejection_message)
    @rejection_message = rejection_message
  end

  def run(cart)
    return if cart.discount_code.nil?

    cart.discount_code.reject(message: @rejection_message)
  end
end

CAMPAIGNS = [
  DisableDiscountCodesCampaign.new(REJECTION_MESSAGE),
]

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

Output.cart = Input.cart

Disable discount codes for product

Use this script to disable use of discount codes in the checkout process if specific products are in the cart.

For example, prevent customers from using discount codes if a product tagged with discounted is in the cart.

# ================================ Customizable Settings ================================
# ================================================================
# Disable Discount Code(s) For Products
#
# If any matching discount codes are used, and any matching items
# are in the cart, the discount code is rejected with the entered
# message.
#
#   - 'discount_code_match_type' determines whether the below
#     strings should be an exact or partial match. Can be:
#       - ':exact' for an exact match
#       - ':partial' for a partial match
#   - 'discount_codes' is a list of strings to identify discount
#     codes
#   - 'product_selector_match_type' determines whether we look for
#     products that do or don't match the entered selectors. Can
#     be:
#       - ':include' to check if the product does match
#       - ':exclude' to make sure the product doesn't match
#   - 'product_selector_type' determines how eligible products
#     will be identified. Can be either:
#       - ':tag' to find products by tag
#       - ':type' to find products by type
#       - ':vendor' to find products by vendor
#       - ':product_id' to find products by ID
#       - ':variant_id' to find products by variant ID
#       - ':subscription' to find subscription products
#       - ':all' for all products
#   - 'product_selectors' is a list of identifiers (from above)
#     for qualifying products. Product/Variant ID lists should
#     only contain numbers (ie. no quotes). If ':all' is used,
#     this can also be 'nil'.
#   - 'rejection_message' is the message to show when a discount
#     code is rejected
# ================================================================
REJECT_DISCOUNT_CODE_FOR_PRODUCTS = [
  {
    discount_code_match_type: :exact,
    discount_codes: ["TESTCODE1", "TESTCODE2"],
    product_selector_match_type: :include,
    product_selector_type: :tag,
    product_selectors: ["discounted"],
    rejection_message: "Discount codes can't be used with 'discounted' products"
  }
]

# ================================ Script Code (do not edit) ================================
# ================================================================
# DiscountCodeSelector
#
# Finds whether the supplied discount code matches any of the
# entered codes.
# ================================================================
class DiscountCodeSelector
  def initialize(match_type, discount_codes)
    @comparator = match_type == :exact ? '==' : 'include?'
    @discount_codes = discount_codes.map { |discount_code| discount_code.upcase.strip }
  end

  def match?(discount_code)
    @discount_codes.any? { |code| discount_code.code.upcase.send(@comparator, code) }
  end
end

# ================================================================
# ProductSelector
#
# Finds matching products by the entered criteria.
# ================================================================
class ProductSelector
  def initialize(match_type, selector_type, selectors)
    @match_type = match_type
    @comparator = match_type == :include ? 'any?' : 'none?'
    @selector_type = selector_type
    @selectors = selectors
  end

  def match?(line_item)
    if self.respond_to?(@selector_type)
      self.send(@selector_type, line_item)
    else
      raise RuntimeError.new('Invalid product selector type')
    end
  end

  def tag(line_item)
    product_tags = line_item.variant.product.tags.map { |tag| tag.downcase.strip }
    @selectors = @selectors.map { |selector| selector.downcase.strip }
    (@selectors & product_tags).send(@comparator)
  end

  def type(line_item)
    @selectors = @selectors.map { |selector| selector.downcase.strip }
    (@match_type == :include) == @selectors.include?(line_item.variant.product.product_type.downcase.strip)
  end

  def vendor(line_item)
    @selectors = @selectors.map { |selector| selector.downcase.strip }
    (@match_type == :include) == @selectors.include?(line_item.variant.product.vendor.downcase.strip)
  end

  def product_id(line_item)
    (@match_type == :include) == @selectors.include?(line_item.variant.product.id)
  end

  def variant_id(line_item)
    (@match_type == :include) == @selectors.include?(line_item.variant.id)
  end

  def subscription(line_item)
    !line_item.selling_plan_id.nil?
  end

  def all(line_item)
    true
  end
end

# ================================================================
# DisableDiscountCodesForProductsCampaign
#
# If any matching discount codes are used, and any matching items
# are in the cart, the discount code is rejected with the entered
# message.
# ================================================================
class DisableDiscountCodesForProductsCampaign
  def initialize(campaigns)
    @campaigns = campaigns
  end

  def run(cart)
    return if cart.discount_code.nil?

    @campaigns.each do |campaign|
      discount_code_selector = DiscountCodeSelector.new(
        campaign[:discount_code_match_type],
        campaign[:discount_codes]
      )

      next unless discount_code_selector.match?(cart.discount_code)

      product_selector = ProductSelector.new(
        campaign[:product_selector_match_type],
        campaign[:product_selector_type],
        campaign[:product_selectors],
      )

      next unless cart.line_items.any? { |line_item| product_selector.match?(line_item) }

      cart.discount_code.reject(message: campaign[:rejection_message])
    end
  end
end

CAMPAIGNS = [
  DisableDiscountCodesForProductsCampaign.new(REJECT_DISCOUNT_CODE_FOR_PRODUCTS),
]

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

Output.cart = Input.cart

Limit Product Quantities

Use this script to apply quantity limits to specific products.

For example, prevent customers from buying more than 1 'Product X' in a single order.

Note

This script does not prevent the initial adding of the items. It only removes any excess items after the fact. There is no notice to customers that these items have been removed from the cart.

# ================================ Customizable Settings ================================
# ================================================================
# Product Quantity Limits
#
# If the quantity of any matching items is greater than the
# entered threshold, the excess items are removed from the cart.
# It should be noted that there will be no notice to the customer
# when this happens.
#
#   - 'enable' determines whether the campaign will run. Can be:
#       - 'true' to run
#       - 'false' to not run
#   - 'product_selector_match_type' determines whether we look for
#     products that do or don't match the entered selectors. Can
#     be:
#       - ':include' to check if the product does match
#       - ':exclude' to make sure the product doesn't match
#   - 'product_selector_type' determines how eligible products
#     will be identified. Can be either:
#       - ':tag' to find products by tag
#       - ':type' to find products by type
#       - ':vendor' to find products by vendor
#       - ':product_id' to find products by ID
#       - ':variant_id' to find products by variant ID
#       - ':subscription' to find subscription products
#       - ':all' for all products
#   - 'product_selectors' is a list of identifiers (from above)
#     for qualifying products. Product/Variant ID lists should
#     only contain numbers (ie. no quotes). If ':all' is used,
#     this can also be 'nil'.
#   - 'variant_level_limit' determines whether the below limit
#     is applied on a variant, or a total quantity, level. For
#     example, can I have X number of individual matching items,
#     or can I only have X number total of matching items?
#     Can be:
#       - 'true' to limit at a variant level
#       - 'false' to limit total quantity
#   - 'quantity_allowed' is the number of products allowed
# ================================================================
QUANTITY_LIMITS = {
  enable: true,
  campaigns: [
    {
      product_selector_match_type: :include,
      product_selector_type: :tag,
      product_selectors: ["limited"],
      variant_level_limit: true,
      quantity_allowed: 2,
    },
  ]
}

# ================================ Script Code (do not edit) ================================
# ================================================================
# ProductSelector
#
# Finds matching products by the entered criteria.
# ================================================================
class ProductSelector
  def initialize(match_type, selector_type, selectors)
    @match_type = match_type
    @comparator = match_type == :include ? 'any?' : 'none?'
    @selector_type = selector_type
    @selectors = selectors
  end

  def match?(line_item)
    if self.respond_to?(@selector_type)
      self.send(@selector_type, line_item)
    else
      raise RuntimeError.new('Invalid product selector type')
    end
  end

  def tag(line_item)
    product_tags = line_item.variant.product.tags.map { |tag| tag.downcase.strip }
    @selectors = @selectors.map { |selector| selector.downcase.strip }
    (@selectors & product_tags).send(@comparator)
  end

  def type(line_item)
    @selectors = @selectors.map { |selector| selector.downcase.strip }
    (@match_type == :include) == @selectors.include?(line_item.variant.product.product_type.downcase.strip)
  end

  def vendor(line_item)
    @selectors = @selectors.map { |selector| selector.downcase.strip }
    (@match_type == :include) == @selectors.include?(line_item.variant.product.vendor.downcase.strip)
  end

  def product_id(line_item)
    (@match_type == :include) == @selectors.include?(line_item.variant.product.id)
  end

  def variant_id(line_item)
    (@match_type == :include) == @selectors.include?(line_item.variant.id)
  end

  def subscription(line_item)
    !line_item.selling_plan_id.nil?
  end

  def all(line_item)
    true
  end
end

# ================================================================
# ProductQuantityLimitCampaign
#
# If the quantity of any matching items is greater than the
# entered threshold, the excess items are removed from the cart.
# ================================================================
class ProductQuantityLimitCampaign
  def initialize(enable, campaigns)
    @enable = enable
    @campaigns = campaigns
  end

  def run(cart)
    return unless @enable

    @campaigns.each do |campaign|
      product_selector = ProductSelector.new(
        campaign[:product_selector_match_type],
        campaign[:product_selector_type],
        campaign[:product_selectors]
      )

      if campaign[:variant_level_limit]
        applicable_items = {}

        cart.line_items.each do |line_item|
          next unless product_selector.match?(line_item)

          id = line_item.variant.id

          if applicable_items[id].nil?
            applicable_items[id] = {
              items: [],
              total_quantity: 0
            }
          end

          applicable_items[id][:items].push(line_item)
          applicable_items[id][:total_quantity] += line_item.quantity
        end

        next if applicable_items.nil?

        applicable_items.each do |id, info|
          next unless info[:total_quantity] > campaign[:quantity_allowed]

          num_to_remove = info[:total_quantity] - campaign[:quantity_allowed]
          self.loop_items(cart, info[:items], num_to_remove)
        end
      else
        applicable_items = cart.line_items.select { |line_item| product_selector.match?(line_item) }

        next if applicable_items.nil?

        total_quantity = applicable_items.map(&:quantity).reduce(0, :+)

        next unless total_quantity > campaign[:quantity_allowed]

        num_to_remove = total_quantity - campaign[:quantity_allowed]
        self.loop_items(cart, applicable_items, num_to_remove)
      end
    end
  end

  def loop_items(cart, line_items, num_to_remove)
    line_items.each do |line_item|
      if line_item.quantity > num_to_remove
        split_line_item = line_item.split(take: num_to_remove)
        break
      else
        index = cart.line_items.find_index(line_item)
        cart.line_items.delete_at(index)
        num_to_remove -= line_item.quantity
      end

      break if num_to_remove <= 0
    end
  end
end

CAMPAIGNS = [
  ProductQuantityLimitCampaign.new(
    QUANTITY_LIMITS[:enable],
    QUANTITY_LIMITS[:campaigns],
  ),
]

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

Output.cart = Input.cart