fix: ReturnCheckPayment (#411)

* update request interface

* added tiny test

Author: axshani

tests/checkPayments.spec.ts

@@ -1,4 +1,4 @@
-import { CheckPayment, CreateCheckPaymentRequest, Unit } from "../unit"
+import { CheckPayment, CreateCheckPaymentRequest, ReturnCheckPaymentRequest, Unit } from "../unit"
 
 import dotenv from "dotenv"
 dotenv.config()
@@ -153,4 +153,19 @@ describe("Test Check Payments", () => {
           }
       })
     })
+    
+    test("Test ReturnCheckPayment Resource", () => {
+      const request: ReturnCheckPaymentRequest = {
+        id: "1234",
+        data: {
+          "type": "checkPaymentReturn",
+          "attributes": {
+            "reason": "StopPayment"
+          }
+        }
+      }
+
+      expect(request.id).toBe("1234")
+      expect(request.data.type).toBe("checkPaymentReturn")
+    })
 })

types/checkPayment.ts

@@ -214,7 +214,7 @@ export interface ReturnCheckPaymentRequest {
             /**
              * The reason for returning the Check Payment. see [valid reasons for Check Payment returns](https://docs.unit.co/check-payments#check-payment-return-reasons) list.
              */
-            returnReasonCode: string
+            reason: CheckPaymentReturnReason
         }
     }
 }