Merge decorator specs with Spree's ones

They are now isolated from each other.

spec/models/spree/payment_original_spec.rb

@@ -820,4 +820,90 @@
       end
     end
   end
+
+  context 'OFN specs from previously decorated model' do
+    describe "applying transaction fees" do
+      let!(:order) { create(:order) }
+      let!(:line_item) { create(:line_item, order: order, quantity: 3, price: 5.00) }
+
+      before do
+        order.reload.update!
+      end
+
+      context "to Stripe payments" do
+        let(:shop) { create(:enterprise) }
+        let(:payment_method) { create(:stripe_payment_method, distributor_ids: [create(:distributor_enterprise).id], preferred_enterprise_id: shop.id) }
+        let(:payment) { create(:payment, order: order, payment_method: payment_method, amount: order.total) }
+        let(:calculator) { Spree::Calculator::FlatPercentItemTotal.new(preferred_flat_percent: 10) }
+
+        before do
+          payment_method.calculator = calculator
+          payment_method.save!
+
+          allow(order).to receive(:pending_payments) { [payment] }
+        end
+
+        context "when the payment fails" do
+          let(:failed_response) { ActiveMerchant::Billing::Response.new(false, "This is an error message") }
+
+          before do
+            allow(payment_method).to receive(:purchase) { failed_response }
+          end
+
+          it "makes the transaction fee ineligible and finalizes it" do
+            # Decided to wrap the save process in order.process_payments!
+            # since that is the context it is usually performed in
+            order.process_payments!
+            expect(order.payments.count).to eq 1
+            expect(order.payments).to include payment
+            expect(payment.state).to eq "failed"
+            expect(payment.adjustment.eligible?).to be false
+            expect(payment.adjustment.finalized?).to be true
+            expect(order.adjustments.payment_fee.count).to eq 1
+            expect(order.adjustments.payment_fee.eligible).to_not include payment.adjustment
+          end
+        end
+
+        context "when the payment information is invalid" do
+          before do
+            allow(payment_method).to receive(:supports?) { false }
+          end
+
+          it "makes the transaction fee ineligible and finalizes it" do
+            # Decided to wrap the save process in order.process_payments!
+            # since that is the context it is usually performed in
+            order.process_payments!
+            expect(order.payments.count).to eq 1
+            expect(order.payments).to include payment
+            expect(payment.state).to eq "invalid"
+            expect(payment.adjustment.eligible?).to be false
+            expect(payment.adjustment.finalized?).to be true
+            expect(order.adjustments.payment_fee.count).to eq 1
+            expect(order.adjustments.payment_fee.eligible).to_not include payment.adjustment
+          end
+        end
+
+        context "when the payment is processed successfully" do
+          let(:successful_response) { ActiveMerchant::Billing::Response.new(true, "Yay!") }
+
+          before do
+            allow(payment_method).to receive(:purchase) { successful_response }
+          end
+
+          it "creates an appropriate adjustment" do
+            # Decided to wrap the save process in order.process_payments!
+            # since that is the context it is usually performed in
+            order.process_payments!
+            expect(order.payments.count).to eq 1
+            expect(order.payments).to include payment
+            expect(payment.state).to eq "completed"
+            expect(payment.adjustment.eligible?).to be true
+            expect(order.adjustments.payment_fee.count).to eq 1
+            expect(order.adjustments.payment_fee.eligible).to include payment.adjustment
+            expect(payment.adjustment.amount).to eq 1.5
+          end
+        end
+      end
+    end
+  end
 end