Add test coverage to recalculating fees and taxes on completed orders

spec/controllers/spree/admin/orders_controller_spec.rb

@@ -77,7 +77,9 @@ describe Spree::Admin::OrdersController, type: :controller do
         let(:user) { create(:admin_user) }
         let(:variant1) { create(:variant) }
         let(:variant2) { create(:variant) }
-        let(:distributor) { create(:distributor_enterprise, allow_order_changes: true) }
+        let(:distributor) {
+          create(:distributor_enterprise, allow_order_changes: true, charges_sales_tax: true)
+        }
         let(:order_cycle) { create(:simple_order_cycle, distributors: [distributor]) }
         let(:enterprise_fee) { create(:enterprise_fee, calculator: build(:calculator_per_item) ) }
         let!(:exchange) { create(:exchange, incoming: true, sender: variant1.product.supplier, receiver: order_cycle.coordinator, variants: [variant1, variant2], enterprise_fees: [enterprise_fee]) }
@@ -140,6 +142,74 @@ describe Spree::Admin::OrdersController, type: :controller do
             expect(order.adjustment_total).to eq 0
           end
         end
+
+        context "with taxes on enterprise fees" do
+          let(:zone) { create(:zone_with_member) }
+          let(:tax_included) { true }
+          let(:tax_rate) {
+            create(:tax_rate, amount: 0.25, included_in_price: tax_included, zone: zone)
+          }
+          let!(:enterprise_fee) {
+            create(:enterprise_fee, tax_category: tax_rate.tax_category, amount: 1)
+          }
+
+          before do
+            allow(order).to receive(:tax_zone) { zone }
+          end
+
+          context "with included taxes" do
+            it "taxes fees correctly" do
+              spree_put :update, { id: order.number }
+              order.reload
+
+              expect(order.all_adjustments.tax.count).to eq 2
+              expect(order.enterprise_fee_tax).to eq 0.4
+
+              expect(order.included_tax_total).to eq 0.4
+              expect(order.additional_tax_total).to eq 0
+            end
+          end
+
+          context "with added taxes" do
+            let(:tax_included) { false }
+
+            it "taxes fees correctly" do
+              spree_put :update, { id: order.number }
+              order.reload
+
+              expect(order.all_adjustments.tax.count).to eq 2
+              expect(order.enterprise_fee_tax).to eq 0.5
+
+              expect(order.included_tax_total).to eq 0
+              expect(order.additional_tax_total).to eq 0.5
+            end
+
+            context "when the order has legacy taxes" do
+              let(:legacy_tax_adjustment) {
+                create(:adjustment, amount: 0.5, included: false, originator: tax_rate,
+                       order: order, adjustable: order, state: "closed")
+              }
+
+              before do
+                order.all_adjustments.tax.delete_all
+                order.adjustments << legacy_tax_adjustment
+              end
+
+              it "removes legacy tax adjustments before recalculating tax" do
+                expect(order.all_adjustments.tax.count).to eq 1
+                expect(order.all_adjustments.tax).to include legacy_tax_adjustment
+                expect(order.additional_tax_total).to eq 0.5
+
+                spree_put :update, { id: order.number }
+                order.reload
+
+                expect(order.all_adjustments.tax.count).to eq 2
+                expect(order.all_adjustments.tax).to_not include legacy_tax_adjustment
+                expect(order.additional_tax_total).to eq 0.5
+              end
+            end
+          end
+        end
       end
     end