Scripts is discounting off automatic conversion rates instead of manual conversion rates

[Avex]

Background

I have markets set up as such:

• Base market is Canada/CAD
• Other markets include US/USD, Japan/JPY etc
• We set manual conversion rates, for USD it's  1 CAD = 0.75 USD
  

• Converted prices are rounded up to the nearest whole dollar.

• Using shopify native currency conversion, no other app.

I have a script running to give 100% off items tagged "FreeGift" if the cart is at least $100 CAD, so a free gift w purchase basically.

Script:

# GENERATED BY THE SHOPIFY SCRIPT CREATOR APP
class Campaign
  def initialize(condition, *qualifiers)
    @condition = (condition.to_s + '?').to_sym
    @qualifiers = PostCartAmountQualifier ? [] : [] rescue qualifiers.compact
    _item_selector = qualifiers.last unless _item_selector
    qualifiers.compact.each do |qualifier|
      is_multi_select = qualifier.instance_variable_get(:@conditions).is_a?(Array)
      if is_multi_select
        qualifier.instance_variable_get(:@conditions).each do |nested_q|
          @post_amount_qualifier = nested_q if nested_q.is_a?(PostCartAmountQualifier)
          @qualifiers << qualifier
        end
      else
        @post_amount_qualifier = qualifier if qualifier.is_a?(PostCartAmountQualifier)
        @qualifiers << qualifier
      end
    end if @qualifiers.empty?
  end

  def qualifies?(cart)
    return true if @qualifiers.empty?
    @unmodified_line_items = cart.line_items.map do |item|
      new_item = item.dup
      new_item.instance_variables.each do |var|
        val = item.instance_variable_get(var)
        new_item.instance_variable_set(var, val.dup) if val.respond_to?(:dup)
      end
      new_item
    end if @post_amount_qualifier
    @qualifiers.send(@condition) do |qualifier|
      is_selector = false
      if qualifier.is_a?(Selector) || qualifier.instance_variable_get(:@conditions).any? { |q| q.is_a?(Selector) }
        is_selector = true
      end rescue nil
      if is_selector
        raise "Missing line item match type" if _match_type.nil?
        cart.line_items.send(@li_match_type) { |item| qualifier.match?(item) }
      else
        qualifier.match?(cart, _item_selector)
      end
    end
  end

  def run_with_hooks(cart)
    before_run(cart) if respond_to?(:before_run)
    run(cart)
    after_run(cart)
  end

  def after_run(cart)
    .apply_final_discount if  && .respond_to?(:apply_final_discount)
    revert_changes(cart) unless @post_amount_qualifier.nil? || @post_amount_qualifier.match?(cart)
  end

  def revert_changes(cart)
    cart.instance_variable_set(:@line_items, @unmodified_line_items)
  end
end

class ConditionalDiscount < Campaign
  def initialize(condition, customer_qualifier, cart_qualifier, line_item_selector, discount, max_discounts)
    super(condition, customer_qualifier, cart_qualifier)
    _item_selector = line_item_selector
     = discount
    @items_to_discount = max_discounts == 0 ? nil : max_discounts
  end

  def run(cart)
    raise "Campaign requires a discount" unless 
    return unless qualifies?(cart)
    applicable_items = cart.line_items.select { |item| _item_selector.nil? || _item_selector.match?(item) }
    applicable_items = applicable_items.sort_by { |item| item.variant.price }
    applicable_items.each do |item|
      break if @items_to_discount == 0
      if (!@items_to_discount.nil? && item.quantity > @items_to_discount)
        discounted_items = item.split(take: @items_to_discount)
        .apply(discounted_items)
        cart.line_items << discounted_items
        @items_to_discount = 0
      else
        .apply(item)
        @items_to_discount -= item.quantity if !@items_to_discount.nil?
      end
    end
  end
end

class Qualifier
  def partial_match(match_type, item_info, possible_matches)
    match_type = (match_type.to_s + '?').to_sym
    if item_info.kind_of?(Array)
      possible_matches.any? do |possibility|
        item_info.any? do |search|
          search.send(match_type, possibility)
        end
      end
    else
      possible_matches.any? do |possibility|
        item_info.send(match_type, possibility)
      end
    end
  end

  def compare_amounts(compare, comparison_type, compare_to)
    case comparison_type
      when :greater_than
        return compare > compare_to
      when :greater_than_or_equal
        return compare >= compare_to
      when :less_than
        return compare < compare_to
      when :less_than_or_equal
        return compare <= compare_to
      when :equal_to
        return compare == compare_to
      else
        raise "Invalid comparison type"
    end
  end
end

class PostCartAmountQualifier < Qualifier
  def initialize(comparison_type, amount)
    @comparison_type = comparison_type
    @amount = Money.new(cents: amount * 100)
  end

  def match?(cart, selector = nil)
    total = cart.subtotal_price
    compare_amounts(total, @comparison_type, @amount)
  end
end

class Selector
  def partial_match(match_type, item_info, possible_matches)
    match_type = (match_type.to_s + '?').to_sym
    if item_info.kind_of?(Array)
      possible_matches.any? do |possibility|
        item_info.any? do |search|
          search.send(match_type, possibility)
        end
      end
    else
      possible_matches.any? do |possibility|
        item_info.send(match_type, possibility)
      end
    end
  end
end

class ProductTagSelector < Selector
  def initialize(match_type, match_condition, tags)
    _condition = match_condition
    @invert = match_type == :does_not
     = tags.map(&:downcase)
  end

  def match?(line_item)
    product_tags = line_item.variant.product.tags.to_a.map(&:downcase)
    case _condition
      when :match
        return @invert ^ ((@tags & product_tags).length > 0)
      else
        return @invert ^ partial_match(@match_condition, product_tags, )
    end
  end
end

class PercentageDiscount
  def initialize(percent, message)
     = (100 - percent) / 100.0
    @message = message
  end

  def apply(line_item)
    line_item.change_line_price(line_item.line_price * , message: @message)
  end
end

CAMPAIGNS = [
  ConditionalDiscount.new(
    :all,
    nil,
    PostCartAmountQualifier.new(
      :greater_than_or_equal,
      100
    ),
    ProductTagSelector.new(
      :does,
      :match,
      ["FreeGift"]
    ),
    PercentageDiscount.new(
      100,
      "Free Gift"
    ),
    1
  )
].freeze

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

Output.cart = Input.cart

The sample free gift product is a Mask, which is $15 CAD and $11.15 USD rounded to $12 at the manual conversion rate.

Issue

On a CAD cart of over $100 it's fine, item is discounted 100% to free:

However, on a USD converted cart...

There is a residual amount of money.

I changed the USD exchange rate to automatic (which at this time is about 78 cents to 1CAD, making the mask $11.83 USD rounded to $12 USD) 

And sure enough, the discount takes off 100% to free.

I would expect the discount to take 100% off the price achieved by the manual rate, not the automatic rate!