test adjusting tail after insert at tail position

Author: xyn22

src/data-structures/linked-list/__test__/LinkedList.test.js

@@ -43,8 +43,10 @@ describe('LinkedList', () => {
     linkedList.insert(2, 1);
     linkedList.insert(1, -7);
     linkedList.insert(10, 9);
-
-    expect(linkedList.toString()).toBe('1,4,2,3,10');
+    linkedList.insert(7, 5);
+    expect(linkedList.toString()).toBe('1,4,2,3,10,7');
+    expect(linkedList.head.toString()).toBe('1');
+    expect(linkedList.tail.toString()).toBe('7');
   });
 
   it('should delete node by value from linked list', () => {