merge: Add test case and fix TimSort algo (TheAlgorithms#977)

Author: Ankush263

Sorts/TimSort.js

@@ -25,6 +25,7 @@ const Timsort = (array) => {
       Merge(array, left, mid, right)
     }
   }
+  return array
 }
 
 /**

Sorts/test/TimSort.test.js

@@ -0,0 +1,25 @@
+import { Timsort } from '../TimSort'
+
+test('The Timsort of the array [5, 4, 3, 2, 1] is [1, 2, 3, 4, 5]', () => {
+  const arr = [5, 4, 3, 2, 1]
+  const res = Timsort(arr)
+  expect(res).toEqual([1, 2, 3, 4, 5])
+})
+
+test('The Timsort of the array [] is []', () => {
+  const arr = []
+  const res = Timsort(arr)
+  expect(res).toEqual([])
+})
+
+test('The Timsort of the array [-5, -4, -3, -2, -1] is [-5, -4, -3, -2, -1]', () => {
+  const arr = [-5, -4, -3, -2, -1]
+  const res = Timsort(arr)
+  expect(res).toEqual([-5, -4, -3, -2, -1])
+})
+
+test('The Timsort of the array [9, 0, -5, -11, 3] is [-11, -5, 0, 3, 9]', () => {
+  const arr = [9, 0, -5, -11, 3]
+  const res = Timsort(arr)
+  expect(res).toEqual([-11, -5, 0, 3, 9])
+})