[Vouchers] Fix tax included in price amount

app/helpers/admin/orders_helper.rb

@@ -2,12 +2,30 @@
 
 module Admin
   module OrdersHelper
+    AdjustmentData = Struct.new(:label, :amount)
+
     # Adjustments to display under "Order adjustments".
     #
     # We exclude shipping method adjustments because they are displayed in a
     # separate table together with the order line items.
     def order_adjustments_for_display(order)
-      order.adjustments + order.all_adjustments.payment_fee.eligible
+      order.adjustments +
+        voucher_included_tax_representations(order) +
+        order.all_adjustments.payment_fee.eligible
+    end
+
+    def voucher_included_tax_representations(order)
+      return [] unless VoucherAdjustmentsService.new(order).voucher_included_tax.negative?
+
+      adjustment = order.voucher_adjustments.first
+
+      [
+        AdjustmentData.new(
+          I18n.t("admin.orders.edit.voucher_tax_included_in_price",
+                 label: adjustment.label),
+          adjustment.included_tax
+        )
+      ]
     end
   end
 end

app/helpers/checkout_helper.rb

@@ -53,7 +53,9 @@ def display_checkout_subtotal(order)
   end
 
   def display_checkout_tax_total(order)
-    Spree::Money.new order.total_tax, currency: order.currency
+    total_tax = order.total_tax + VoucherAdjustmentsService.new(order).voucher_included_tax
+
+    Spree::Money.new(total_tax, currency: order.currency)
   end
 
   def display_checkout_taxes_hash(order)

config/locales/en.yml

@@ -974,6 +974,7 @@ en:
     orders:
       edit:
         order_sure_want_to: Are you sure you want to %{event} this order?
+        voucher_tax_included_in_price: "%{label} (tax included in voucher)"
       invoice_email_sent: 'Invoice email has been sent'
       order_email_resent: 'Order email has been resent'
       bulk_management:

spec/helpers/admin/orders_helper_spec.rb

@@ -5,6 +5,12 @@
 describe Admin::OrdersHelper, type: :helper do
   describe "#order_adjustments_for_display" do
     let(:order) { create(:order) }
+    let(:service) { instance_double(VoucherAdjustmentsService, voucher_included_tax:) }
+    let(:voucher_included_tax) { 0.0 }
+
+    before do
+      allow(VoucherAdjustmentsService).to receive(:new).and_return(service)
+    end
 
     it "selects eligible adjustments" do
       adjustment = create(:adjustment, order:, adjustable: order, amount: 1)
@@ -32,5 +38,22 @@
 
       expect(helper.order_adjustments_for_display(order)).to eq []
     end
+
+    context "with a voucher with tax included in price" do
+      let(:enterprise) { build(:enterprise) }
+      let(:voucher) do
+        create(:voucher_flat_rate, code: 'new_code', enterprise:, amount: 10)
+      end
+      let(:voucher_included_tax) { -0.5 }
+
+      it "includes a fake tax voucher adjustment" do
+        voucher_adjustment = voucher.create_adjustment(voucher.code, order)
+        voucher_adjustment.update(included_tax: voucher_included_tax)
+
+        fake_adjustment = helper.order_adjustments_for_display(order).last
+        expect(fake_adjustment.label).to eq("new_code (tax included in price)")
+        expect(fake_adjustment.amount).to eq(-0.5)
+      end
+    end
   end
 end

spec/helpers/checkout_helper_spec.rb

@@ -15,12 +15,27 @@
     helper.validated_input("test", "foo", type: :email)
   end
 
-  describe "displaying the tax total for an order" do
-    let(:order) { double(:order, total_tax: 123.45, currency: 'AUD') }
+  describe "#display_checkout_tax_total" do
+    subject(:display_checkout_tax_total) { helper.display_checkout_tax_total(order) }
+
+    let(:order) { instance_double(Spree::Order, total_tax: 123.45, currency: 'AUD') }
+    let(:service) { instance_double(VoucherAdjustmentsService, voucher_included_tax: ) }
+    let(:voucher_included_tax) { 0.0 }
+
+    before do
+      allow(VoucherAdjustmentsService).to receive(:new).and_return(service)
+    end
 
     it "retrieves the total tax on the order" do
-      expect(helper.display_checkout_tax_total(order)).to eq(Spree::Money.new(123.45,
-                                                                              currency: 'AUD'))
+      expect(display_checkout_tax_total).to eq(Spree::Money.new(123.45, currency: 'AUD'))
+    end
+
+    context "with a voucher" do
+      let(:voucher_included_tax) { -0.45 }
+
+      it "displays the discounted total tax" do
+        expect(display_checkout_tax_total).to eq(Spree::Money.new(123.00, currency: 'AUD'))
+      end
     end
   end
 

spec/system/consumer/checkout/tax_incl_spec.rb

@@ -131,7 +131,7 @@
           # UI checks
           expect(page).to have_content("Confirmed")
           expect(page).to have_selector('#order_total', text: with_currency(0.00))
-          expect(page).to have_selector('#tax-row', text: with_currency(1.15))
+          expect(page).to have_selector('#tax-row', text: with_currency(0.00))
 
           # Voucher
           within "#line-items" do