fix(payment): validate total amount when refunding payment (#8437)

Co-authored-by: Carlos R. L. Rodrigues <37986729+carlos-r-l-rodrigues@users.noreply.github.com>

packages/modules/payment/integration-tests/__tests__/services/payment-module/index.spec.ts

@@ -1,12 +1,12 @@
 import { IPaymentModuleService } from "@medusajs/types"
 import { Module, Modules, promiseAll } from "@medusajs/utils"
+import { PaymentModuleService } from "@services"
 import { moduleIntegrationTestRunner } from "medusa-test-utils"
 import {
   createPaymentCollections,
   createPayments,
   createPaymentSessions,
 } from "../../../__fixtures__"
-import { PaymentModuleService } from "@services"
 
 jest.setTimeout(30000)
 
@@ -693,6 +693,41 @@ moduleIntegrationTestRunner<IPaymentModuleService>({
               "You cannot refund more than what is captured on the payment."
             )
           })
+
+          it("should throw if total refunded amount is greater than captured amount", async () => {
+            await service.capturePayment({
+              amount: 100,
+              payment_id: "pay-id-1",
+            })
+
+            const refundedPayment1 = await service.refundPayment({
+              amount: 50,
+              payment_id: "pay-id-1",
+            })
+
+            expect(refundedPayment1).toEqual(
+              expect.objectContaining({
+                id: "pay-id-1",
+                amount: 100,
+                refunds: [
+                  expect.objectContaining({
+                    amount: 50,
+                  }),
+                ],
+              })
+            )
+
+            const error = await service
+              .refundPayment({
+                amount: 60,
+                payment_id: "pay-id-1",
+              })
+              .catch((e) => e)
+
+            expect(error.message).toEqual(
+              "You cannot refund more than what is captured on the payment."
+            )
+          })
         })
 
         describe("cancel", () => {

packages/modules/payment/src/services/payment-module.ts

@@ -750,7 +750,7 @@ export default class PaymentModuleService
           "amount",
           "raw_amount",
         ],
-        relations: ["captures.raw_amount"],
+        relations: ["captures.raw_amount", "refunds.raw_amount"],
       },
       sharedContext
     )
@@ -763,9 +763,16 @@ export default class PaymentModuleService
       const amountAsBigNumber = new BigNumber(next.raw_amount)
       return MathBN.add(captureAmount, amountAsBigNumber)
     }, MathBN.convert(0))
-    const refundAmount = new BigNumber(data.amount)
+    const refundedAmount = payment.refunds.reduce((refundedAmount, next) => {
+      return MathBN.add(refundedAmount, next.raw_amount)
+    }, MathBN.convert(0))
 
-    if (MathBN.lt(capturedAmount, refundAmount)) {
+    const totalRefundedAmount = MathBN.add(
+      refundedAmount,
+      data.amount
+    )
+
+    if (MathBN.lt(capturedAmount, totalRefundedAmount)) {
       throw new MedusaError(
         MedusaError.Types.INVALID_DATA,
         `You cannot refund more than what is captured on the payment.`