From 1ecf3e8d8cd64280552fee521529e738829db8d9 Mon Sep 17 00:00:00 2001
From: Dennis Eichhorn <spl1nes.com@googlemail.com>
Date: Wed, 9 Oct 2019 17:45:53 +0200
Subject: [PATCH] adding sort and making sure original list is unchanged after
 sort

---
 Algorithm/Sort/HeapSort.php                   |   2 +-
 Algorithm/Sort/MergeSort.php                  | 121 ++++++++++++++++++
 tests/Algorithm/Sort/BitonicSortTest.php      |   8 ++
 tests/Algorithm/Sort/BubbleSortTest.php       |   8 ++
 tests/Algorithm/Sort/BucketSortTest.php       |   8 ++
 .../Algorithm/Sort/CocktailShakerSortTest.php |   8 ++
 tests/Algorithm/Sort/CombSortTest.php         |   8 ++
 tests/Algorithm/Sort/CycleSortTest.php        |   8 ++
 tests/Algorithm/Sort/GnomeSortTest.php        |   8 ++
 tests/Algorithm/Sort/HeapSortTest.php         |  10 +-
 tests/Algorithm/Sort/InsertionSortTest.php    |  10 +-
 tests/Algorithm/Sort/IntroSortTest.php        |  10 +-
 tests/Algorithm/Sort/MergeSortTest.php        |  65 ++++++++++
 tests/Algorithm/Sort/OddEvenSortTest.php      |   8 ++
 tests/Algorithm/Sort/QuickSortTest.php        |   8 ++
 tests/Algorithm/Sort/SelectionSortTest.php    |   8 ++
 16 files changed, 294 insertions(+), 4 deletions(-)
 create mode 100644 tests/Algorithm/Sort/MergeSortTest.php

diff --git a/Algorithm/Sort/HeapSort.php b/Algorithm/Sort/HeapSort.php
index 000f4c248..dccac4acd 100644
--- a/Algorithm/Sort/HeapSort.php
+++ b/Algorithm/Sort/HeapSort.php
@@ -54,7 +54,7 @@ class HeapSort implements SortInterface
      * @param array $list  Data to sort
      * @param int   $size  Heap size
      * @param int   $index Index element
-     * @param itn   $order Sort order
+     * @param int   $order Sort order
      *
      * @return void
      *
diff --git a/Algorithm/Sort/MergeSort.php b/Algorithm/Sort/MergeSort.php
index e69de29bb..31e63d406 100644
--- a/Algorithm/Sort/MergeSort.php
+++ b/Algorithm/Sort/MergeSort.php
@@ -0,0 +1,121 @@
+<?php
+/**
+ * Orange Management
+ *
+ * PHP Version 7.4
+ *
+ * @package   phpOMS\Algorithm\Sort;
+ * @copyright Dennis Eichhorn
+ * @license   OMS License 1.0
+ * @version   1.0.0
+ * @link      https://orange-management.org
+ */
+declare(strict_types=1);
+
+namespace phpOMS\Algorithm\Sort;
+
+/**
+ * MergeSort class.
+ *
+ * @package phpOMS\Algorithm\Sort;
+ * @license OMS License 1.0
+ * @link    https://orange-management.org
+ * @since   1.0.0
+ */
+class MergeSort implements SortInterface
+{
+    /**
+     * {@inheritdoc}
+     */
+    public static function sort(array $list, int $order = SortOrder::ASC) : array
+    {
+        $clone = $list;
+        self::sortHalve($clone, 0, \count($list) - 1, $order);
+
+        return $clone;
+    }
+
+    /**
+     * Recursive sorting of halve of the list and then merging it
+     *
+     * @param array $list  Data to sort
+     * @param int   $lo    Start of the list to sort
+     * @param int   $hi    End of the list to sort
+     * @param int   $order Sort order
+     *
+     * @return void
+     *
+     * @since 1.0.0
+     */
+    private static function sortHalve(array &$list, int $lo, int $hi, int $order) : void
+    {
+        if ($lo >= $hi) {
+            return;
+        }
+
+        $mi = (int) ($lo + ($hi - $lo) / 2);
+
+        self::sortHalve($list, $lo, $mi, $order);
+        self::sortHalve($list, $mi + 1, $hi, $order);
+
+        self::merge($list, $lo, $mi, $hi, $order);
+    }
+
+    /**
+     * Merge and sort sub list
+     *
+     * @param array $list  Data to sort
+     * @param int   $lo    Start of the list to sort
+     * @param int   $mi    Middle point of the list to sort
+     * @param int   $hi    End of the list to sort
+     * @param int   $order Sort order
+     *
+     * @return void
+     *
+     * @since 1.0.0
+     */
+    private static function merge(array &$list, int $lo, int $mi, int $hi, int $order) : void
+    {
+        $n1 = $mi - $lo + 1;
+        $n2 = $hi - $mi;
+
+        $loList = [];
+        $hiList = [];
+
+        for ($i = 0; $i < $n1; ++$i) {
+            $loList[$i] = $list[$lo + $i];
+        }
+
+        for ($i = 0; $i < $n2; ++$i) {
+            $hiList[$i] = $list[$mi + 1 + $i];
+        }
+
+        $i = 0;
+        $j = 0;
+        $k = $lo;
+
+        while ($i < $n1 && $j < $n2) {
+            if (!$loList[$i]->compare($hiList[$j], $order)) {
+                $list[$k] = $loList[$i];
+                ++$i;
+            } else {
+                $list[$k] = $hiList[$j];
+                ++$j;
+            }
+
+            ++$k;
+        }
+
+        while ($i < $n1) {
+            $list[$k] = $loList[$i];
+            ++$i;
+            ++$k;
+        }
+
+        while ($j < $n2) {
+            $list[$k] = $hiList[$j];
+            ++$j;
+            ++$k;
+        }
+    }
+}
diff --git a/tests/Algorithm/Sort/BitonicSortTest.php b/tests/Algorithm/Sort/BitonicSortTest.php
index 4c2dac541..8eabf0b78 100644
--- a/tests/Algorithm/Sort/BitonicSortTest.php
+++ b/tests/Algorithm/Sort/BitonicSortTest.php
@@ -44,6 +44,10 @@ class BitonicSortTest extends \PHPUnit\Framework\TestCase
         self::assertEquals(
             [1, 2, 4, 5], [$newList[0]->value, $newList[1]->value, $newList[2]->value, $newList[3]->value]
         );
+
+        self::assertEquals(
+            [5, 1, 4, 2], [$this->list[0]->value, $this->list[1]->value, $this->list[2]->value, $this->list[3]->value, $this->list[4]->value,]
+        );
     }
 
     public function testSortDESC() : void
@@ -52,5 +56,9 @@ class BitonicSortTest extends \PHPUnit\Framework\TestCase
         self::assertEquals(
             [5, 4, 2, 1], [$newList[0]->value, $newList[1]->value, $newList[2]->value, $newList[3]->value]
         );
+
+        self::assertEquals(
+            [5, 1, 4, 2], [$this->list[0]->value, $this->list[1]->value, $this->list[2]->value, $this->list[3]->value, $this->list[4]->value,]
+        );
     }
 }
diff --git a/tests/Algorithm/Sort/BubbleSortTest.php b/tests/Algorithm/Sort/BubbleSortTest.php
index f9c84044d..19165bfd0 100644
--- a/tests/Algorithm/Sort/BubbleSortTest.php
+++ b/tests/Algorithm/Sort/BubbleSortTest.php
@@ -45,6 +45,10 @@ class BubbleSortTest extends \PHPUnit\Framework\TestCase
         self::assertEquals(
             [1, 2, 4, 5, 8], [$newList[0]->value, $newList[1]->value, $newList[2]->value, $newList[3]->value, $newList[4]->value,]
         );
+
+        self::assertEquals(
+            [5, 1, 4, 2, 8], [$this->list[0]->value, $this->list[1]->value, $this->list[2]->value, $this->list[3]->value, $this->list[4]->value,]
+        );
     }
 
     public function testSortDESC() : void
@@ -53,5 +57,9 @@ class BubbleSortTest extends \PHPUnit\Framework\TestCase
         self::assertEquals(
             [8, 5, 4, 2, 1], [$newList[0]->value, $newList[1]->value, $newList[2]->value, $newList[3]->value, $newList[4]->value,]
         );
+
+        self::assertEquals(
+            [5, 1, 4, 2, 8], [$this->list[0]->value, $this->list[1]->value, $this->list[2]->value, $this->list[3]->value, $this->list[4]->value,]
+        );
     }
 }
diff --git a/tests/Algorithm/Sort/BucketSortTest.php b/tests/Algorithm/Sort/BucketSortTest.php
index a5e843116..b3296c050 100644
--- a/tests/Algorithm/Sort/BucketSortTest.php
+++ b/tests/Algorithm/Sort/BucketSortTest.php
@@ -45,6 +45,10 @@ class BucketSortTest extends \PHPUnit\Framework\TestCase
         self::assertEquals(
             [1, 2, 4, 5, 8], [$newList[0]->value, $newList[1]->value, $newList[2]->value, $newList[3]->value, $newList[4]->value,]
         );
+
+        self::assertEquals(
+            [5, 1, 4, 2, 8], [$this->list[0]->value, $this->list[1]->value, $this->list[2]->value, $this->list[3]->value, $this->list[4]->value,]
+        );
     }
 
     public function testSortDESC() : void
@@ -53,5 +57,9 @@ class BucketSortTest extends \PHPUnit\Framework\TestCase
         self::assertEquals(
             [8, 5, 4, 2, 1], [$newList[0]->value, $newList[1]->value, $newList[2]->value, $newList[3]->value, $newList[4]->value,]
         );
+
+        self::assertEquals(
+            [5, 1, 4, 2, 8], [$this->list[0]->value, $this->list[1]->value, $this->list[2]->value, $this->list[3]->value, $this->list[4]->value,]
+        );
     }
 }
diff --git a/tests/Algorithm/Sort/CocktailShakerSortTest.php b/tests/Algorithm/Sort/CocktailShakerSortTest.php
index 050770118..cc52197fe 100644
--- a/tests/Algorithm/Sort/CocktailShakerSortTest.php
+++ b/tests/Algorithm/Sort/CocktailShakerSortTest.php
@@ -45,6 +45,10 @@ class CocktailShakerSortTest extends \PHPUnit\Framework\TestCase
         self::assertEquals(
             [1, 2, 4, 5, 8], [$newList[0]->value, $newList[1]->value, $newList[2]->value, $newList[3]->value, $newList[4]->value,]
         );
+
+        self::assertEquals(
+            [5, 1, 4, 2, 8], [$this->list[0]->value, $this->list[1]->value, $this->list[2]->value, $this->list[3]->value, $this->list[4]->value,]
+        );
     }
 
     public function testSortDESC() : void
@@ -53,5 +57,9 @@ class CocktailShakerSortTest extends \PHPUnit\Framework\TestCase
         self::assertEquals(
             [8, 5, 4, 2, 1], [$newList[0]->value, $newList[1]->value, $newList[2]->value, $newList[3]->value, $newList[4]->value,]
         );
+
+        self::assertEquals(
+            [5, 1, 4, 2, 8], [$this->list[0]->value, $this->list[1]->value, $this->list[2]->value, $this->list[3]->value, $this->list[4]->value,]
+        );
     }
 }
diff --git a/tests/Algorithm/Sort/CombSortTest.php b/tests/Algorithm/Sort/CombSortTest.php
index 1bc590181..634bc6877 100644
--- a/tests/Algorithm/Sort/CombSortTest.php
+++ b/tests/Algorithm/Sort/CombSortTest.php
@@ -45,6 +45,10 @@ class CombSortTest extends \PHPUnit\Framework\TestCase
         self::assertEquals(
             [1, 2, 4, 5, 8], [$newList[0]->value, $newList[1]->value, $newList[2]->value, $newList[3]->value, $newList[4]->value,]
         );
+
+        self::assertEquals(
+            [5, 1, 4, 2, 8], [$this->list[0]->value, $this->list[1]->value, $this->list[2]->value, $this->list[3]->value, $this->list[4]->value,]
+        );
     }
 
     public function testSortDESC() : void
@@ -53,5 +57,9 @@ class CombSortTest extends \PHPUnit\Framework\TestCase
         self::assertEquals(
             [8, 5, 4, 2, 1], [$newList[0]->value, $newList[1]->value, $newList[2]->value, $newList[3]->value, $newList[4]->value,]
         );
+
+        self::assertEquals(
+            [5, 1, 4, 2, 8], [$this->list[0]->value, $this->list[1]->value, $this->list[2]->value, $this->list[3]->value, $this->list[4]->value,]
+        );
     }
 }
diff --git a/tests/Algorithm/Sort/CycleSortTest.php b/tests/Algorithm/Sort/CycleSortTest.php
index 5b3f6f0f2..4953cc244 100644
--- a/tests/Algorithm/Sort/CycleSortTest.php
+++ b/tests/Algorithm/Sort/CycleSortTest.php
@@ -45,6 +45,10 @@ class CycleSortTest extends \PHPUnit\Framework\TestCase
         self::assertEquals(
             [1, 2, 4, 5, 8], [$newList[0]->value, $newList[1]->value, $newList[2]->value, $newList[3]->value, $newList[4]->value,]
         );
+
+        self::assertEquals(
+            [5, 1, 4, 2, 8], [$this->list[0]->value, $this->list[1]->value, $this->list[2]->value, $this->list[3]->value, $this->list[4]->value,]
+        );
     }
 
     public function testSortDESC() : void
@@ -53,5 +57,9 @@ class CycleSortTest extends \PHPUnit\Framework\TestCase
         self::assertEquals(
             [8, 5, 4, 2, 1], [$newList[0]->value, $newList[1]->value, $newList[2]->value, $newList[3]->value, $newList[4]->value,]
         );
+
+        self::assertEquals(
+            [5, 1, 4, 2, 8], [$this->list[0]->value, $this->list[1]->value, $this->list[2]->value, $this->list[3]->value, $this->list[4]->value,]
+        );
     }
 }
diff --git a/tests/Algorithm/Sort/GnomeSortTest.php b/tests/Algorithm/Sort/GnomeSortTest.php
index b0959fc68..921f1be53 100644
--- a/tests/Algorithm/Sort/GnomeSortTest.php
+++ b/tests/Algorithm/Sort/GnomeSortTest.php
@@ -45,6 +45,10 @@ class GnomeSortTest extends \PHPUnit\Framework\TestCase
         self::assertEquals(
             [1, 2, 4, 5, 8], [$newList[0]->value, $newList[1]->value, $newList[2]->value, $newList[3]->value, $newList[4]->value,]
         );
+
+        self::assertEquals(
+            [5, 1, 4, 2, 8], [$this->list[0]->value, $this->list[1]->value, $this->list[2]->value, $this->list[3]->value, $this->list[4]->value,]
+        );
     }
 
     public function testSortDESC() : void
@@ -53,5 +57,9 @@ class GnomeSortTest extends \PHPUnit\Framework\TestCase
         self::assertEquals(
             [8, 5, 4, 2, 1], [$newList[0]->value, $newList[1]->value, $newList[2]->value, $newList[3]->value, $newList[4]->value,]
         );
+
+        self::assertEquals(
+            [5, 1, 4, 2, 8], [$this->list[0]->value, $this->list[1]->value, $this->list[2]->value, $this->list[3]->value, $this->list[4]->value,]
+        );
     }
 }
diff --git a/tests/Algorithm/Sort/HeapSortTest.php b/tests/Algorithm/Sort/HeapSortTest.php
index b16e84a13..08e819568 100644
--- a/tests/Algorithm/Sort/HeapSortTest.php
+++ b/tests/Algorithm/Sort/HeapSortTest.php
@@ -20,7 +20,7 @@ use phpOMS\Algorithm\Sort\SortOrder;
 require_once __DIR__ . '/../../Autoloader.php';
 
 /**
- * @testdox phpOMS\tests\Algorithm\Sort: Bucket sort test
+ * @testdox phpOMS\tests\Algorithm\Sort: Heap sort test
  *
  * @internal
  */
@@ -45,6 +45,10 @@ class HeapSortTest extends \PHPUnit\Framework\TestCase
         self::assertEquals(
             [1, 2, 4, 5, 8], [$newList[0]->value, $newList[1]->value, $newList[2]->value, $newList[3]->value, $newList[4]->value,]
         );
+
+        self::assertEquals(
+            [5, 1, 4, 2, 8], [$this->list[0]->value, $this->list[1]->value, $this->list[2]->value, $this->list[3]->value, $this->list[4]->value,]
+        );
     }
 
     public function testSortDESC() : void
@@ -53,5 +57,9 @@ class HeapSortTest extends \PHPUnit\Framework\TestCase
         self::assertEquals(
             [8, 5, 4, 2, 1], [$newList[0]->value, $newList[1]->value, $newList[2]->value, $newList[3]->value, $newList[4]->value,]
         );
+
+        self::assertEquals(
+            [5, 1, 4, 2, 8], [$this->list[0]->value, $this->list[1]->value, $this->list[2]->value, $this->list[3]->value, $this->list[4]->value,]
+        );
     }
 }
diff --git a/tests/Algorithm/Sort/InsertionSortTest.php b/tests/Algorithm/Sort/InsertionSortTest.php
index 5b7ee8c94..8ea67c611 100644
--- a/tests/Algorithm/Sort/InsertionSortTest.php
+++ b/tests/Algorithm/Sort/InsertionSortTest.php
@@ -20,7 +20,7 @@ use phpOMS\Algorithm\Sort\SortOrder;
 require_once __DIR__ . '/../../Autoloader.php';
 
 /**
- * @testdox phpOMS\tests\Algorithm\Sort: Bucket sort test
+ * @testdox phpOMS\tests\Algorithm\Sort: Insertion sort test
  *
  * @internal
  */
@@ -45,6 +45,10 @@ class InsertionSortTest extends \PHPUnit\Framework\TestCase
         self::assertEquals(
             [1, 2, 4, 5, 8], [$newList[0]->value, $newList[1]->value, $newList[2]->value, $newList[3]->value, $newList[4]->value,]
         );
+
+        self::assertEquals(
+            [5, 1, 4, 2, 8], [$this->list[0]->value, $this->list[1]->value, $this->list[2]->value, $this->list[3]->value, $this->list[4]->value,]
+        );
     }
 
     public function testSortDESC() : void
@@ -53,5 +57,9 @@ class InsertionSortTest extends \PHPUnit\Framework\TestCase
         self::assertEquals(
             [8, 5, 4, 2, 1], [$newList[0]->value, $newList[1]->value, $newList[2]->value, $newList[3]->value, $newList[4]->value,]
         );
+
+        self::assertEquals(
+            [5, 1, 4, 2, 8], [$this->list[0]->value, $this->list[1]->value, $this->list[2]->value, $this->list[3]->value, $this->list[4]->value,]
+        );
     }
 }
diff --git a/tests/Algorithm/Sort/IntroSortTest.php b/tests/Algorithm/Sort/IntroSortTest.php
index 4d68bb53b..aaa5bcfe4 100644
--- a/tests/Algorithm/Sort/IntroSortTest.php
+++ b/tests/Algorithm/Sort/IntroSortTest.php
@@ -20,7 +20,7 @@ use phpOMS\Algorithm\Sort\SortOrder;
 require_once __DIR__ . '/../../Autoloader.php';
 
 /**
- * @testdox phpOMS\tests\Algorithm\Sort: Bucket sort test
+ * @testdox phpOMS\tests\Algorithm\Sort: Intro sort test
  *
  * @internal
  */
@@ -45,6 +45,10 @@ class IntroSortTest extends \PHPUnit\Framework\TestCase
         self::assertEquals(
             [1, 2, 4, 5, 8], [$newList[0]->value, $newList[1]->value, $newList[2]->value, $newList[3]->value, $newList[4]->value,]
         );
+
+        self::assertEquals(
+            [5, 1, 4, 2, 8], [$this->list[0]->value, $this->list[1]->value, $this->list[2]->value, $this->list[3]->value, $this->list[4]->value,]
+        );
     }
 
     public function testSortDESC() : void
@@ -53,5 +57,9 @@ class IntroSortTest extends \PHPUnit\Framework\TestCase
         self::assertEquals(
             [8, 5, 4, 2, 1], [$newList[0]->value, $newList[1]->value, $newList[2]->value, $newList[3]->value, $newList[4]->value,]
         );
+
+        self::assertEquals(
+            [5, 1, 4, 2, 8], [$this->list[0]->value, $this->list[1]->value, $this->list[2]->value, $this->list[3]->value, $this->list[4]->value,]
+        );
     }
 }
diff --git a/tests/Algorithm/Sort/MergeSortTest.php b/tests/Algorithm/Sort/MergeSortTest.php
new file mode 100644
index 000000000..17eee9eaa
--- /dev/null
+++ b/tests/Algorithm/Sort/MergeSortTest.php
@@ -0,0 +1,65 @@
+<?php
+/**
+ * Orange Management
+ *
+ * PHP Version 7.4
+ *
+ * @package   tests
+ * @copyright Dennis Eichhorn
+ * @license   OMS License 1.0
+ * @version   1.0.0
+ * @link      https://orange-management.org
+ */
+ declare(strict_types=1);
+
+namespace phpOMS\tests\Algorithm\Sort;
+
+use phpOMS\Algorithm\Sort\MergeSort;
+use phpOMS\Algorithm\Sort\SortOrder;
+
+require_once __DIR__ . '/../../Autoloader.php';
+
+/**
+ * @testdox phpOMS\tests\Algorithm\Sort: Merge sort test
+ *
+ * @internal
+ */
+class MergeSortTest extends \PHPUnit\Framework\TestCase
+{
+    protected $list = [];
+
+    protected function setUp() : void
+    {
+        $this->list = [
+            new NumericElement(5),
+            new NumericElement(1),
+            new NumericElement(4),
+            new NumericElement(2),
+            new NumericElement(8),
+        ];
+    }
+
+    public function testSortASC() : void
+    {
+        $newList = MergeSort::sort($this->list);
+        self::assertEquals(
+            [1, 2, 4, 5, 8], [$newList[0]->value, $newList[1]->value, $newList[2]->value, $newList[3]->value, $newList[4]->value,]
+        );
+
+        self::assertEquals(
+            [5, 1, 4, 2, 8], [$this->list[0]->value, $this->list[1]->value, $this->list[2]->value, $this->list[3]->value, $this->list[4]->value,]
+        );
+    }
+
+    public function testSortDESC() : void
+    {
+        $newList = MergeSort::sort($this->list, SortOrder::DESC);
+        self::assertEquals(
+            [8, 5, 4, 2, 1], [$newList[0]->value, $newList[1]->value, $newList[2]->value, $newList[3]->value, $newList[4]->value,]
+        );
+
+        self::assertEquals(
+            [5, 1, 4, 2, 8], [$this->list[0]->value, $this->list[1]->value, $this->list[2]->value, $this->list[3]->value, $this->list[4]->value,]
+        );
+    }
+}
diff --git a/tests/Algorithm/Sort/OddEvenSortTest.php b/tests/Algorithm/Sort/OddEvenSortTest.php
index d070bd6e9..8546844a4 100644
--- a/tests/Algorithm/Sort/OddEvenSortTest.php
+++ b/tests/Algorithm/Sort/OddEvenSortTest.php
@@ -45,6 +45,10 @@ class OddEvenSortTest extends \PHPUnit\Framework\TestCase
         self::assertEquals(
             [1, 2, 4, 5, 8], [$newList[0]->value, $newList[1]->value, $newList[2]->value, $newList[3]->value, $newList[4]->value,]
         );
+
+        self::assertEquals(
+            [5, 1, 4, 2, 8], [$this->list[0]->value, $this->list[1]->value, $this->list[2]->value, $this->list[3]->value, $this->list[4]->value,]
+        );
     }
 
     public function testSortDESC() : void
@@ -53,5 +57,9 @@ class OddEvenSortTest extends \PHPUnit\Framework\TestCase
         self::assertEquals(
             [8, 5, 4, 2, 1], [$newList[0]->value, $newList[1]->value, $newList[2]->value, $newList[3]->value, $newList[4]->value,]
         );
+
+        self::assertEquals(
+            [5, 1, 4, 2, 8], [$this->list[0]->value, $this->list[1]->value, $this->list[2]->value, $this->list[3]->value, $this->list[4]->value,]
+        );
     }
 }
diff --git a/tests/Algorithm/Sort/QuickSortTest.php b/tests/Algorithm/Sort/QuickSortTest.php
index bbdc9285d..8c2174474 100644
--- a/tests/Algorithm/Sort/QuickSortTest.php
+++ b/tests/Algorithm/Sort/QuickSortTest.php
@@ -45,6 +45,10 @@ class QuickSortTest extends \PHPUnit\Framework\TestCase
         self::assertEquals(
             [1, 2, 4, 5, 8], [$newList[0]->value, $newList[1]->value, $newList[2]->value, $newList[3]->value, $newList[4]->value,]
         );
+
+        self::assertEquals(
+            [5, 1, 4, 2, 8], [$this->list[0]->value, $this->list[1]->value, $this->list[2]->value, $this->list[3]->value, $this->list[4]->value,]
+        );
     }
 
     public function testSortDESC() : void
@@ -53,5 +57,9 @@ class QuickSortTest extends \PHPUnit\Framework\TestCase
         self::assertEquals(
             [8, 5, 4, 2, 1], [$newList[0]->value, $newList[1]->value, $newList[2]->value, $newList[3]->value, $newList[4]->value,]
         );
+
+        self::assertEquals(
+            [5, 1, 4, 2, 8], [$this->list[0]->value, $this->list[1]->value, $this->list[2]->value, $this->list[3]->value, $this->list[4]->value,]
+        );
     }
 }
diff --git a/tests/Algorithm/Sort/SelectionSortTest.php b/tests/Algorithm/Sort/SelectionSortTest.php
index 19164bb59..764c7ee11 100644
--- a/tests/Algorithm/Sort/SelectionSortTest.php
+++ b/tests/Algorithm/Sort/SelectionSortTest.php
@@ -45,6 +45,10 @@ class SelectionSortTest extends \PHPUnit\Framework\TestCase
         self::assertEquals(
             [1, 2, 4, 5, 8], [$newList[0]->value, $newList[1]->value, $newList[2]->value, $newList[3]->value, $newList[4]->value,]
         );
+
+        self::assertEquals(
+            [5, 1, 4, 2, 8], [$this->list[0]->value, $this->list[1]->value, $this->list[2]->value, $this->list[3]->value, $this->list[4]->value,]
+        );
     }
 
     public function testSortDESC() : void
@@ -53,5 +57,9 @@ class SelectionSortTest extends \PHPUnit\Framework\TestCase
         self::assertEquals(
             [8, 5, 4, 2, 1], [$newList[0]->value, $newList[1]->value, $newList[2]->value, $newList[3]->value, $newList[4]->value,]
         );
+
+        self::assertEquals(
+            [5, 1, 4, 2, 8], [$this->list[0]->value, $this->list[1]->value, $this->list[2]->value, $this->list[3]->value, $this->list[4]->value,]
+        );
     }
 }