chore: simplify conditional item hydration

Author: dreamorosi

Diff for: packages/idempotency/src/persistence/DynamoDBPersistenceLayer.ts

@@ -200,10 +200,7 @@ class DynamoDBPersistenceLayer extends BasePersistenceLayer {
         })
       );
     } catch (error) {
-      if (error instanceof ConditionalCheckFailedException) {
-        if (!error.Item) {
-          throw new Error('item is undefined');
-        }
+      if (error instanceof ConditionalCheckFailedException && error.Item) {
         const item = unmarshall(error.Item);
         throw new IdempotencyItemAlreadyExistsError(
           `Failed to put record for already existing idempotency key: ${record.idempotencyKey}`,

Diff for: packages/idempotency/tests/unit/persistence/DynamoDbPersistenceLayer.test.ts

@@ -688,7 +688,6 @@ describe('Class: DynamoDBPersistenceLayer', () => {
     });
   });
 
-  //write test for when Item is undefined
   test('_putRecord throws Error when Item is undefined', async () => {
     // Prepare
     const persistenceLayer = new TestDynamoDBPersistenceLayer({
@@ -706,8 +705,8 @@ describe('Class: DynamoDBPersistenceLayer', () => {
         $metadata: {},
       })
     );
-    await expect(persistenceLayer._putRecord(mockRecord)).rejects.toThrowError(
-      'item is undefined'
-    );
+    await expect(
+      persistenceLayer._putRecord(mockRecord)
+    ).rejects.toThrowError();
   });
 });