diff --git a/src/hackerrank/interview_preparation_kit/arrays/2d_array.js b/src/hackerrank/interview_preparation_kit/arrays/2d_array.js
index bae6bb05..d6474676 100644
--- a/src/hackerrank/interview_preparation_kit/arrays/2d_array.js
+++ b/src/hackerrank/interview_preparation_kit/arrays/2d_array.js
@@ -2,7 +2,7 @@
  * @link Problem definition [[docs/hackerrank/interview_preparation_kit/arrays/2d_array.md]]
  */
 
-export function gethourGlass(arr, positionX, positionY) {
+function gethourGlass(arr, positionX, positionY) {
   const result = [];
 
   // top
@@ -18,7 +18,7 @@ export function gethourGlass(arr, positionX, positionY) {
   return result;
 }
 
-export function hourglassSum(arr) {
+function hourglassSum(arr) {
   let matrixSize = 0;
 
   if (arr?.[0]) {
diff --git a/src/hackerrank/interview_preparation_kit/arrays/2d_array.test.js b/src/hackerrank/interview_preparation_kit/arrays/2d_array.test.js
index 2b67bd17..c15f0072 100644
--- a/src/hackerrank/interview_preparation_kit/arrays/2d_array.test.js
+++ b/src/hackerrank/interview_preparation_kit/arrays/2d_array.test.js
@@ -1,15 +1,15 @@
 import { describe, expect, it } from '@jest/globals';
 import { logger as console } from '../../../logger.js';
 
-import { hourglassSum } from './2d_array.js';
+import twoDArray from './2d_array.js';
 import TEST_CASES from './2d_array.testcases_test.json';
 
 describe('arrays: 2d Array hourglassSum', () => {
   it('hourglassSum Test Cases', () => {
-    expect.assertions(1);
+    expect.assertions(3);
 
     TEST_CASES.forEach((test) => {
-      const answer = hourglassSum(test.input);
+      const answer = twoDArray.hourglassSum(test.input);
 
       console.debug(
         `gethourGlass(${test.input.toString()}) solution found: ${answer}`
diff --git a/src/hackerrank/interview_preparation_kit/arrays/2d_array.testcases_test.json b/src/hackerrank/interview_preparation_kit/arrays/2d_array.testcases_test.json
index f32bdef3..91ecbd7d 100644
--- a/src/hackerrank/interview_preparation_kit/arrays/2d_array.testcases_test.json
+++ b/src/hackerrank/interview_preparation_kit/arrays/2d_array.testcases_test.json
@@ -10,5 +10,29 @@
       [0, 0, 1, 2, 4, 0]
     ],
     "expected": 19
+  },
+  {
+    "title": "Sample Test Case 1",
+    "input": [
+      [1, 1, 1, 0, 0, 0],
+      [0, 1, 0, 0, 0, 0],
+      [1, 1, 1, 0, 0, 0],
+      [0, 9, 2, -4, -4, 0],
+      [0, 0, 0, -2, 0, 0],
+      [0, 0, -1, -2, -4, 0]
+    ],
+    "expected": 13
+  },
+  {
+    "title": "Sample Test Case 2",
+    "input": [
+      [-9, -9, -9, 1, 1, 1],
+      [0, -9, 0, 4, 3, 2],
+      [-9, -9, -9, 1, 2, 3],
+      [0, 0, 8, 6, 6, 0],
+      [0, 0, 0, -2, 0, 0],
+      [0, 0, 1, 2, 4, 0]
+    ],
+    "expected": 28
   }
 ]