From 76d17d75a8fe3227bcba5776dff4eccc56cca28c Mon Sep 17 00:00:00 2001
From: Imre Balassa <imre.balassa@trolex.com>
Date: Sat, 7 Jul 2018 01:38:35 +0200
Subject: [PATCH] Delete the root element from the tree.

---
 .../src/main/java/com/baeldung/tree/BinaryTree.java |  2 +-
 ...{BinaryTreeTest.java => BinaryTreeUnitTest.java} | 13 ++++++++++++-
 .../trie/{TrieTest.java => TrieUnitTest.java}       |  2 +-
 3 files changed, 14 insertions(+), 3 deletions(-)
 rename data-structures/src/test/java/com/baeldung/tree/{BinaryTreeTest.java => BinaryTreeUnitTest.java} (90%)
 rename data-structures/src/test/java/com/baeldung/trie/{TrieTest.java => TrieUnitTest.java} (98%)

diff --git a/data-structures/src/main/java/com/baeldung/tree/BinaryTree.java b/data-structures/src/main/java/com/baeldung/tree/BinaryTree.java
index e3179dca32..f435e41afa 100644
--- a/data-structures/src/main/java/com/baeldung/tree/BinaryTree.java
+++ b/data-structures/src/main/java/com/baeldung/tree/BinaryTree.java
@@ -57,7 +57,7 @@ public class BinaryTree {
     }
 
     public void delete(int value) {
-        deleteRecursive(root, value);
+        root = deleteRecursive(root, value);
     }
 
     private Node deleteRecursive(Node current, int value) {
diff --git a/data-structures/src/test/java/com/baeldung/tree/BinaryTreeTest.java b/data-structures/src/test/java/com/baeldung/tree/BinaryTreeUnitTest.java
similarity index 90%
rename from data-structures/src/test/java/com/baeldung/tree/BinaryTreeTest.java
rename to data-structures/src/test/java/com/baeldung/tree/BinaryTreeUnitTest.java
index 99e656fe28..f81247b74d 100644
--- a/data-structures/src/test/java/com/baeldung/tree/BinaryTreeTest.java
+++ b/data-structures/src/test/java/com/baeldung/tree/BinaryTreeUnitTest.java
@@ -6,7 +6,7 @@ import static org.junit.Assert.assertTrue;
 
 import org.junit.Test;
 
-public class BinaryTreeTest {
+public class BinaryTreeUnitTest {
 
     @Test
     public void givenABinaryTree_WhenAddingElements_ThenTreeNotEmpty() {
@@ -70,6 +70,17 @@ public class BinaryTreeTest {
         assertEquals(initialSize, bt.getSize());
     }
 
+    @Test
+    public void it_deletes_the_root() {
+        int value = 12;
+        BinaryTree bt = new BinaryTree();
+        bt.add(value);
+
+        assertTrue(bt.containsNode(value));
+        bt.delete(value);
+        assertFalse(bt.containsNode(value));
+    }
+
     @Test
     public void givenABinaryTree_WhenTraversingInOrder_ThenPrintValues() {
 
diff --git a/data-structures/src/test/java/com/baeldung/trie/TrieTest.java b/data-structures/src/test/java/com/baeldung/trie/TrieUnitTest.java
similarity index 98%
rename from data-structures/src/test/java/com/baeldung/trie/TrieTest.java
rename to data-structures/src/test/java/com/baeldung/trie/TrieUnitTest.java
index be7e5575d8..3dd3f27a60 100644
--- a/data-structures/src/test/java/com/baeldung/trie/TrieTest.java
+++ b/data-structures/src/test/java/com/baeldung/trie/TrieUnitTest.java
@@ -5,7 +5,7 @@ import org.junit.Test;
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertTrue;
 
-public class TrieTest {
+public class TrieUnitTest {
 
     @Test
     public void whenEmptyTrie_thenNoElements() {