created custom error with existingRecord field

Author: tolutheo

packages/idempotency/src/errors.ts

@@ -1,7 +1,18 @@
+import { AttributeValue } from '@aws-sdk/client-dynamodb';
 /**
  * Item attempting to be inserted into persistence store already exists and is not expired
  */
-class IdempotencyItemAlreadyExistsError extends Error {}
+class IdempotencyItemAlreadyExistsError extends Error {
+  public existingRecord: Record<string, AttributeValue> | undefined;
+
+  public constructor(
+    message: string,
+    existingRecord: Record<string, AttributeValue> | undefined
+  ) {
+    super(message);
+    this.existingRecord = existingRecord;
+  }
+}
 
 /**
  * Item does not exist in persistence store