diff --git a/tests/unit/framework/util/ArrayHelperTest.php b/tests/unit/framework/helpers/ArrayHelperTest.php
similarity index 97%
rename from tests/unit/framework/util/ArrayHelperTest.php
rename to tests/unit/framework/helpers/ArrayHelperTest.php
index 117c702..187217f 100644
--- a/tests/unit/framework/util/ArrayHelperTest.php
+++ b/tests/unit/framework/helpers/ArrayHelperTest.php
@@ -1,6 +1,6 @@
 <?php
 
-namespace yiiunit\framework\util;
+namespace yiiunit\framework\helpers;
 
 use yii\helpers\ArrayHelper;
 
diff --git a/tests/unit/framework/util/HtmlTest.php b/tests/unit/framework/helpers/HtmlTest.php
similarity index 99%
rename from tests/unit/framework/util/HtmlTest.php
rename to tests/unit/framework/helpers/HtmlTest.php
index eba1a20..2c3de72 100644
--- a/tests/unit/framework/util/HtmlTest.php
+++ b/tests/unit/framework/helpers/HtmlTest.php
@@ -1,6 +1,6 @@
 <?php
 
-namespace yiiunit\framework\util;
+namespace yiiunit\framework\helpers;
 
 use Yii;
 use yii\helpers\Html;
diff --git a/tests/unit/framework/helpers/StringHelperTest.php b/tests/unit/framework/helpers/StringHelperTest.php
new file mode 100644
index 0000000..4e1266f
--- /dev/null
+++ b/tests/unit/framework/helpers/StringHelperTest.php
@@ -0,0 +1,73 @@
+<?php
+namespace yiiunit\framework\helpers;
+use \yii\helpers\StringHelper as StringHelper;
+
+/**
+ * StringHelperTest
+ */
+class StringHelperTest extends \yii\test\TestCase
+{
+	public function testStrlen()
+	{
+		$this->assertEquals(4, StringHelper::strlen('this'));
+		$this->assertEquals(6, StringHelper::strlen('это'));
+	}
+
+	public function testSubstr()
+	{
+		$this->assertEquals('th', StringHelper::substr('this', 0, 2));
+		$this->assertEquals('э', StringHelper::substr('это', 0, 2));
+	}
+
+	public function testPluralize()
+	{
+		$testData = array(
+			'move' => 'moves',
+			'foot' => 'feet',
+			'child' => 'children',
+			'human' => 'humans',
+			'man' => 'men',
+			'staff' => 'staff',
+			'tooth' => 'teeth',
+			'person' => 'people',
+			'mouse' => 'mice',
+			'touch' => 'touches',
+			'hash' => 'hashes',
+			'shelf' => 'shelves',
+			'potato' => 'potatoes',
+			'bus' => 'buses',
+			'test' => 'tests',
+			'car' => 'cars',
+		);
+
+		foreach($testData as $testIn => $testOut) {
+			$this->assertEquals($testOut, StringHelper::pluralize($testIn));
+			$this->assertEquals(ucfirst($testOut), ucfirst(StringHelper::pluralize($testIn)));
+		}
+	}
+
+	public function testCamel2words()
+	{
+		$this->assertEquals('Camel Case', StringHelper::camel2words('camelCase'));
+		$this->assertEquals('Lower Case', StringHelper::camel2words('lower_case'));
+		$this->assertEquals('Tricky Stuff It Is Testing', StringHelper::camel2words(' tricky_stuff.it-is testing... '));
+	}
+
+	public function testCamel2id()
+	{
+		$this->assertEquals('post-tag', StringHelper::camel2id('PostTag'));
+		$this->assertEquals('post_tag', StringHelper::camel2id('PostTag', '_'));
+
+		$this->assertEquals('post-tag', StringHelper::camel2id('postTag'));
+		$this->assertEquals('post_tag', StringHelper::camel2id('postTag', '_'));
+	}
+
+	public function testId2camel()
+	{
+		$this->assertEquals('PostTag', StringHelper::id2camel('post-tag'));
+		$this->assertEquals('PostTag', StringHelper::id2camel('post_tag', '_'));
+
+		$this->assertEquals('PostTag', StringHelper::id2camel('post-tag'));
+		$this->assertEquals('PostTag', StringHelper::id2camel('post_tag', '_'));
+	}
+}
\ No newline at end of file