diff --git a/lib/internal/Magento/Framework/Config/Dom.php b/lib/internal/Magento/Framework/Config/Dom.php
index 9c4dde0710c02..6e611e722e41b 100644
--- a/lib/internal/Magento/Framework/Config/Dom.php
+++ b/lib/internal/Magento/Framework/Config/Dom.php
@@ -4,8 +4,6 @@
  * See COPYING.txt for license details.
  */
 
-// @codingStandardsIgnoreFile
-
 /**
  * Magento configuration XML DOM utility
  */
@@ -120,7 +118,7 @@ public function __construct(
     /**
      * Retrieve array of xml errors
      *
-     * @param $errorFormat
+     * @param string $errorFormat
      * @return string[]
      */
     private static function getXmlErrors($errorFormat)
@@ -171,15 +169,10 @@ protected function _mergeNode(\DOMElement $node, $parentPath)
         /* Update matched node attributes and value */
         if ($matchedNode) {
             //different node type
-            if ($this->typeAttributeName && $node->hasAttribute(
-                $this->typeAttributeName
-            ) && $matchedNode->hasAttribute(
-                $this->typeAttributeName
-            ) && $node->getAttribute(
-                $this->typeAttributeName
-            ) !== $matchedNode->getAttribute(
-                $this->typeAttributeName
-            )
+            if ($this->typeAttributeName &&
+                $node->hasAttribute($this->typeAttributeName) &&
+                $matchedNode->hasAttribute($this->typeAttributeName) &&
+                $node->getAttribute($this->typeAttributeName) !== $matchedNode->getAttribute($this->typeAttributeName)
             ) {
                 $parentMatchedNode = $this->_getMatchedNode($parentPath);
                 $newNode = $this->dom->importNode($node, true);
@@ -247,7 +240,7 @@ protected function _mergeAttributes($baseNode, $mergeNode)
      */
     protected function _getNodePathByParent(\DOMElement $node, $parentPath)
     {
-        $prefix = is_null($this->rootNamespace) ? '' : self::ROOT_NAMESPACE_PREFIX . ':';
+        $prefix = $this->rootNamespace === null ? '' : self::ROOT_NAMESPACE_PREFIX . ':';
         $path = $parentPath . '/' . $prefix . $node->tagName;
         $idAttribute = $this->nodeMergingConfig->getIdAttribute($path);
         if (is_array($idAttribute)) {
@@ -441,7 +434,7 @@ public function setSchemaFile($schemaFile)
      */
     private function _getAttributeName($attribute)
     {
-        if (!is_null($attribute->prefix) && !empty($attribute->prefix)) {
+        if ($attribute->prefix !== null && !empty($attribute->prefix)) {
             $attributeName = $attribute->prefix . ':' . $attribute->name;
         } else {
             $attributeName = $attribute->name;
diff --git a/lib/internal/Magento/Framework/Config/Test/Unit/Composer/PackageTest.php b/lib/internal/Magento/Framework/Config/Test/Unit/Composer/PackageTest.php
index 7a2e44462c590..7dccef0cc2aa3 100644
--- a/lib/internal/Magento/Framework/Config/Test/Unit/Composer/PackageTest.php
+++ b/lib/internal/Magento/Framework/Config/Test/Unit/Composer/PackageTest.php
@@ -4,8 +4,6 @@
  * See COPYING.txt for license details.
  */
 
-// @codingStandardsIgnoreFile
-
 namespace Magento\Framework\Config\Test\Unit\Composer;
 
 use \Magento\Framework\Config\Composer\Package;
diff --git a/lib/internal/Magento/Framework/Config/Test/Unit/DataTest.php b/lib/internal/Magento/Framework/Config/Test/Unit/DataTest.php
index 648dd723d8a9f..1d7e685ac771a 100644
--- a/lib/internal/Magento/Framework/Config/Test/Unit/DataTest.php
+++ b/lib/internal/Magento/Framework/Config/Test/Unit/DataTest.php
@@ -4,13 +4,11 @@
  * See COPYING.txt for license details.
  */
 
-// @codingStandardsIgnoreFile
-
 namespace Magento\Framework\Config\Test\Unit;
 
 class DataTest extends \PHPUnit_Framework_TestCase
 {
-   /**
+    /**
      * @var \Magento\Framework\Config\ReaderInterface|\PHPUnit_Framework_MockObject_MockObject
      */
     private $readerMock;