From 863dbdbac394a48829facada054971dd76659815 Mon Sep 17 00:00:00 2001
From: Oleksii Trekhleb <trehleb@gmail.com>
Date: Fri, 13 Jul 2018 17:48:27 +0300
Subject: [PATCH] Fix issue #98.

---
 .../tree/binary-search-tree/BinarySearchTreeNode.js      | 3 +++
 .../__test__/BinarySearchTreeNode.test.js                | 9 +++++++++
 2 files changed, 12 insertions(+)

diff --git a/src/data-structures/tree/binary-search-tree/BinarySearchTreeNode.js b/src/data-structures/tree/binary-search-tree/BinarySearchTreeNode.js
index d821ee89..314f8e06 100644
--- a/src/data-structures/tree/binary-search-tree/BinarySearchTreeNode.js
+++ b/src/data-structures/tree/binary-search-tree/BinarySearchTreeNode.js
@@ -132,6 +132,9 @@ export default class BinarySearchTreeNode extends BinaryTreeNode {
       }
     }
 
+    // Clear the parent of removed node.
+    nodeToRemove.parent = null;
+
     return true;
   }
 
diff --git a/src/data-structures/tree/binary-search-tree/__test__/BinarySearchTreeNode.test.js b/src/data-structures/tree/binary-search-tree/__test__/BinarySearchTreeNode.test.js
index 63b9d999..3efd918f 100644
--- a/src/data-structures/tree/binary-search-tree/__test__/BinarySearchTreeNode.test.js
+++ b/src/data-structures/tree/binary-search-tree/__test__/BinarySearchTreeNode.test.js
@@ -243,4 +243,13 @@ describe('BinarySearchTreeNode', () => {
 
     expect(bstNode.findMin().value).toEqual(obj1);
   });
+
+  it('should abandon removed node', () => {
+    const rootNode = new BinarySearchTreeNode('foo');
+    rootNode.insert('bar');
+    const childNode = rootNode.find('bar');
+    rootNode.remove('bar');
+
+    expect(childNode.parent).toBeNull();
+  });
 });