PLUG-5623 - Add refund function

examples/refundTransaction.ts

@@ -0,0 +1,14 @@
+import { createPayNLClient } from '../src/index.ts';
+
+const payNL = createPayNLClient({ username: 'AT-1234-5678', password: 'your-api-token' });
+
+const orderId = '00000000-1111-2222-3333-000000000000';
+
+try {
+    const refund = await payNL.Orders.refund(orderId, 100);
+    console.log(refund.description);
+} catch (error) {
+    console.log(error.statusCode);
+    console.log(error.body?.detail);
+    console.log(error.body?.violations);
+}

src/order/OrderApi.ts

@@ -194,4 +194,19 @@
         );
         return await response.body<Order>();
     }
+
+    /**
+     * Refund an order, with an optional amount. If no amount is specified, the full order amount will be refunded.
+     *
+     * @see https://developer.pay.nl/reference/patch_transactions-transactionid-refund
+     */
+    async refund(orderId: string, amountInCents?: number): Promise<Order> {
+        const response = await this.apiClient.request(
+            new RestApiRequest(`v2/transactions/${orderId}/refund`, {
+                method: 'PATCH',
+                json: { amount: {value: amountInCents ? amountInCents : null} },
+            }),
+        );
+        return await response.body<Order>();
+    }
 }