merge: Add test case and fix HeapSort Algorithm (#969)

Sorts/HeapSortV2.js

@@ -38,4 +38,5 @@ export function heapSort (input) {
 
     heapRoot(input, 0)
   }
+  return input
 }

Sorts/test/HeapSortV2.test.js

@@ -0,0 +1,19 @@
+import { heapSort } from '../HeapSortV2'
+
+test('The heapSort of the array [4, 3, 2, 1] is [1, 2, 3, 4]', () => {
+  const arr = [4, 3, 2, 1]
+  const res = heapSort(arr)
+  expect(res).toEqual([1, 2, 3, 4])
+})
+
+test('The heapSort of the array [] is []', () => {
+  const arr = []
+  const res = heapSort(arr)
+  expect(res).toEqual([])
+})
+
+test('The heapSort of the array [41, 31, 32, 31] is [31, 31, 32, 41]', () => {
+  const arr = [41, 31, 32, 31]
+  const res = heapSort(arr)
+  expect(res).toEqual([31, 31, 32, 41])
+})