feat: frontend unit tests

frontend/tests/utils/helpers/quickSort.test.ts

@@ -0,0 +1,45 @@
+import { quickSort } from '../../../src/static/js/utils/helpers/quickSort';
+
+describe('js/utils/helpers', () => {
+    describe('quickSort', () => {
+        test('Returns the same array reference (in-place) and sorts ascending', () => {
+            const arr = [3, 1, 4, 1, 5, 9, 2];
+            const out = quickSort(arr, 0, arr.length - 1);
+            expect(out).toBe(arr);
+            expect(arr).toEqual([1, 1, 2, 3, 4, 5, 9]);
+        });
+
+        test('Handles already sorted arrays', () => {
+            const arr = [1, 2, 3, 4, 5];
+            quickSort(arr, 0, arr.length - 1);
+            expect(arr).toEqual([1, 2, 3, 4, 5]);
+        });
+
+        test('Handles arrays with duplicates and negative numbers', () => {
+            const arr = [0, -1, -1, 2, 2, 1, 0];
+            quickSort(arr, 0, arr.length - 1);
+            expect(arr).toEqual([-1, -1, 0, 0, 1, 2, 2]);
+        });
+
+        test('Handles single-element array', () => {
+            const single = [42];
+            quickSort(single, 0, single.length - 1);
+            expect(single).toEqual([42]);
+        });
+
+        test('Handles empty range without changes', () => {
+            const arr = [5, 4, 3];
+            // call with left > right (empty range)
+            quickSort(arr, 2, 1);
+            expect(arr).toEqual([5, 4, 3]);
+        });
+
+        test('Sorts subrange correctly without touching elements outside range', () => {
+            const arr = [9, 7, 5, 3, 1, 2, 4, 8, 6];
+            // sort only the middle [2..6]
+            quickSort(arr, 2, 6);
+            // The subrange [5,3,1,2,4] becomes [1,2,3,4,5]
+            expect(arr).toEqual([9, 7, 1, 2, 3, 4, 5, 8, 6]);
+        });
+    });
+});