From b24763e2498fb7dcf67c191f7d17f10a2b15c40a Mon Sep 17 00:00:00 2001
From: Oleksii Trekhleb <trehleb@gmail.com>
Date: Thu, 5 Apr 2018 06:51:45 +0300
Subject: [PATCH] Fix binary tree node.

---
 src/data-structures/tree/BinaryTreeNode.js             |  2 +-
 .../tree/__test__/BinaryTreeNode.test.js               | 10 ++++++++++
 2 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/src/data-structures/tree/BinaryTreeNode.js b/src/data-structures/tree/BinaryTreeNode.js
index e0ed5668..6b0c5d2e 100644
--- a/src/data-structures/tree/BinaryTreeNode.js
+++ b/src/data-structures/tree/BinaryTreeNode.js
@@ -7,7 +7,7 @@ export default class BinaryTreeNode {
   }
 
   get height() {
-    if (!this.left && !this.left) {
+    if (!this.left && !this.right) {
       return 0;
     }
 
diff --git a/src/data-structures/tree/__test__/BinaryTreeNode.test.js b/src/data-structures/tree/__test__/BinaryTreeNode.test.js
index ffce779f..01453fef 100644
--- a/src/data-structures/tree/__test__/BinaryTreeNode.test.js
+++ b/src/data-structures/tree/__test__/BinaryTreeNode.test.js
@@ -140,4 +140,14 @@ describe('BinaryTreeNode', () => {
     expect(grandRight.height).toBe(0);
     expect(grandGrandLeft.height).toBe(0);
   });
+
+  it('should calculate node height for right nodes as well', () => {
+    const root = new BinaryTreeNode(1);
+    const right = new BinaryTreeNode(2);
+
+    root.setRight(right);
+
+    expect(root.height).toBe(1);
+    expect(right.height).toBe(0);
+  });
 });