Added tests for the Arr::shuffle() method

tests/Arr/ShuffleTest.php

@@ -0,0 +1,33 @@
+<?php
+
+namespace Yetii\Tests\Arr;
+
+use PHPUnit\Framework\TestCase;
+use YeTii\General\Arr;
+
+/**
+ * Class ShuffleTest
+ */
+class ShuffleTest extends TestCase
+{
+    /**
+     * @var array
+     */
+    public $testData = [
+        'apples',
+        'oranges',
+        'apples',
+    ];
+
+    /**
+     * Test whether it returns a shuffled array
+     */
+    public function testCanShuffleTheArray()
+    {
+        $array = new Arr($this->testData);
+        $result = $array->shuffle();
+        $this->assertInstanceOf(Arr::class, $result);
+        $this->assertInternalType('array', $result->toArray());
+        $this->assertFalse($result === $this->testData);
+    }
+}