Check insert into empty tree

Programming_Paradigms/bintree_test.py

@@ -14,6 +14,12 @@ class TestBinTree(unittest.TestCase):
         tree.insert(1)
         tree.search(1)
 
+    def test_insert_into_empty_tree(self):
+        tree = BinTree()
+        tree.insert(1)
+        self.assertIsNotNone(tree.root)
+        self.assertIsInstance(tree.root, BinTreeNode)
+        self.assertEqual(tree.root.value, 1)
 
 class TestBinTreeNode(unittest.TestCase):
     def test_creation(self):