server: Raise RefundedAlready vs. Stripe 500

server/polar/refund/service.py

@@ -182,19 +182,28 @@ async def create(
             raise RefundUnknownPayment(order.id, payment_type="order")
 
         refund_total = refund_amount + refund_tax_amount
-        stripe_refund = await stripe_service.create_refund(
-            charge_id=payment.charge_id,
-            amount=refund_total,
-            reason=RefundReason.to_stripe(create_schema.reason),
-            metadata=dict(
-                order_id=str(order.id),
-                charge_id=str(payment.charge_id),
-                amount=str(create_schema.amount),
-                refund_amount=str(refund_amount),
-                refund_tax_amount=str(refund_tax_amount),
-                revoke_benefits="1" if create_schema.revoke_benefits else "0",
-            ),
+        stripe_metadata = dict(
+            order_id=str(order.id),
+            charge_id=str(payment.charge_id),
+            amount=str(create_schema.amount),
+            refund_amount=str(refund_amount),
+            refund_tax_amount=str(refund_tax_amount),
+            revoke_benefits="1" if create_schema.revoke_benefits else "0",
         )
+
+        try:
+            stripe_refund = await stripe_service.create_refund(
+                charge_id=payment.charge_id,
+                amount=refund_total,
+                reason=RefundReason.to_stripe(create_schema.reason),
+                metadata=stripe_metadata,
+            )
+        except stripe_lib.InvalidRequestError as e:
+            if e.code == "charge_already_refunded":
+                raise RefundedAlready(order)
+            else:
+                raise e
+
         internal_create_schema = self.build_create_schema_from_stripe(
             stripe_refund,
             order=order,

server/tests/refunds/test_service.py

@@ -3,6 +3,7 @@
 from unittest.mock import MagicMock
 
 import pytest
+import stripe as stripe_lib
 from httpx import AsyncClient, Response
 from pytest_mock import MockerFixture
 
@@ -25,6 +26,7 @@
 from polar.pledge.service import pledge as pledge_service
 from polar.postgres import AsyncSession
 from polar.refund.schemas import RefundCreate
+from polar.refund.service import RefundedAlready
 from polar.refund.service import refund as refund_service
 from polar.transaction.service.refund import (
     refund_transaction as refund_transaction_service,
@@ -221,6 +223,57 @@ async def assert_transaction_amounts_from_refund(
         return refund_transaction
 
 
+@pytest.mark.asyncio
+class TestCreateAbuse(StripeRefund):
+    async def test_create_repeatedly(
+        self,
+        session: AsyncSession,
+        mocker: MockerFixture,
+        stripe_service_mock: MagicMock,
+        save_fixture: SaveFixture,
+        product: Product,
+        refund_hooks: Hooks,
+        customer: Customer,
+    ) -> None:
+        # Complex Swedish order. $99.9 with 25% VAT = $24.75
+        order, payment = await create_order_and_payment(
+            save_fixture,
+            product=product,
+            customer=customer,
+            amount=1000,
+            tax_amount=250,
+        )
+
+        assert order.refunded_amount == 0
+        assert order.refunded_tax_amount == 0
+
+        stripe_error = stripe_lib.InvalidRequestError(
+            "Charge py_XX has already been refunded.",
+            param=None,
+            code="charge_already_refunded",
+        )
+        stripe_service_mock.create_refund.side_effect = stripe_error
+
+        # Raised by us or Stripe, e.g attempting a POST request in a quick loop
+        with pytest.raises(RefundedAlready):
+            await refund_service.create(
+                session,
+                order,
+                RefundCreate(
+                    order_id=order.id,
+                    reason=RefundReason.service_disruption,
+                    amount=1000,
+                    comment=None,
+                    revoke_benefits=False,
+                ),
+            )
+
+        order = await order_service.get(session, order.id)  # type: ignore
+        assert order
+        assert order.refunded_amount == 0
+        assert order.refunded_tax_amount == 0
+
+
 @pytest.mark.asyncio
 class TestCreatedWebhooks(StripeRefund):
     async def test_valid_pledge_refund(