diff --git a/packages/php/email-editor/tests/unit/Integrations/Utils/Dom_Document_Helper_Test.php b/packages/php/email-editor/tests/unit/Integrations/Utils/Dom_Document_Helper_Test.php
index 3a765a394f..c2cd7c88e9 100644
--- a/packages/php/email-editor/tests/unit/Integrations/Utils/Dom_Document_Helper_Test.php
+++ b/packages/php/email-editor/tests/unit/Integrations/Utils/Dom_Document_Helper_Test.php
@@ -1,45 +1,66 @@
-<?php declare(strict_types = 1);
+<?php
+/**
+ * This file is part of the MailPoet plugin.
+ *
+ * @package MailPoet\EmailEditor
+ */
 
+declare(strict_types = 1);
 namespace MailPoet\EmailEditor\Integrations\Utils;
 
+/**
+ * Unit test for Dom_Document_Helper class.
+ */
 class Dom_Document_Helper_Test extends \MailPoetUnitTest {
+	/**
+	 * Test if finds element.
+	 */
 	public function testItFindsElement(): void {
-		$html              = '<div><p>Some text</p></div>';
-		$domDocumentHelper = new Dom_Document_Helper( $html );
-		$element           = $domDocumentHelper->find_element( 'p' );
-		$empty             = $domDocumentHelper->find_element( 'span' );
+		$html                = '<div><p>Some text</p></div>';
+		$dom_document_helper = new Dom_Document_Helper( $html );
+		$element             = $dom_document_helper->find_element( 'p' );
+		$empty               = $dom_document_helper->find_element( 'span' );
 		$this->assertInstanceOf( \DOMElement::class, $element );
-		$this->assertEquals( 'p', $element->tagName );
+		$this->assertEquals( 'p', $element->tagName ); // phpcs:ignore WordPress.NamingConventions.ValidVariableName.UsedPropertyNotSnakeCase
 		$this->assertNull( $empty );
 	}
 
+	/**
+	 * Test it gets attribute value.
+	 */
 	public function testItGetsAttributeValue(): void {
-		$html              = '<div><p class="some-class">Some text</p></div>';
-		$domDocumentHelper = new Dom_Document_Helper( $html );
-		$element           = $domDocumentHelper->find_element( 'p' );
+		$html                = '<div><p class="some-class">Some text</p></div>';
+		$dom_document_helper = new Dom_Document_Helper( $html );
+		$element             = $dom_document_helper->find_element( 'p' );
 		$this->assertInstanceOf( \DOMElement::class, $element );
-		$this->assertEquals( 'some-class', $domDocumentHelper->get_attribute_value( $element, 'class' ) );
+		$this->assertEquals( 'some-class', $dom_document_helper->get_attribute_value( $element, 'class' ) );
 	}
 
+	/**
+	 * Test it gets outer html.
+	 */
 	public function testItGetsOuterHtml(): void {
-		$html              = '<div><span>Some <strong>text</strong></span></div>';
-		$domDocumentHelper = new Dom_Document_Helper( $html );
-		$element           = $domDocumentHelper->find_element( 'span' );
+		$html                = '<div><span>Some <strong>text</strong></span></div>';
+		$dom_document_helper = new Dom_Document_Helper( $html );
+		$element             = $dom_document_helper->find_element( 'span' );
 		$this->assertInstanceOf( \DOMElement::class, $element );
-		$this->assertEquals( '<span>Some <strong>text</strong></span>', $domDocumentHelper->get_outer_html( $element ) );
+		$this->assertEquals( '<span>Some <strong>text</strong></span>', $dom_document_helper->get_outer_html( $element ) );
 
-		// testings encoding of special characters
-		$html              = '<div><img src="https://test.com/DALL·E-A®∑oecasƒ-803x1024.jpg"></div>';
-		$domDocumentHelper = new Dom_Document_Helper( $html );
-		$element           = $domDocumentHelper->find_element( 'img' );
+		// testings encoding of special characters.
+		$html                = '<div><img src="https://test.com/DALL·E-A®∑oecasƒ-803x1024.jpg"></div>';
+		$dom_document_helper = new Dom_Document_Helper( $html );
+		$element             = $dom_document_helper->find_element( 'img' );
 		$this->assertInstanceOf( \DOMElement::class, $element );
-		$this->assertEquals( '<img src="https://test.com/DALL%C2%B7E-A%C2%AE%E2%88%91oecas%C6%92-803x1024.jpg">', $domDocumentHelper->get_outer_html( $element ) );
+		$this->assertEquals( '<img src="https://test.com/DALL%C2%B7E-A%C2%AE%E2%88%91oecas%C6%92-803x1024.jpg">', $dom_document_helper->get_outer_html( $element ) );
 	}
 
+	/**
+	 * Test it gets element attribute value by tag name.
+	 */
 	public function testItGetsAttributeValueByTagName(): void {
-		$html              = '<div><p class="some-class">Some text</p><p class="second-paragraph"></p></div>';
-		$domDocumentHelper = new Dom_Document_Helper( $html );
-		$this->assertEquals( 'some-class', $domDocumentHelper->get_attribute_value_by_tag_name( 'p', 'class' ) );
-		$this->assertNull( $domDocumentHelper->get_attribute_value_by_tag_name( 'span', 'class' ) );
+		$html                = '<div><p class="some-class">Some text</p><p class="second-paragraph"></p></div>';
+		$dom_document_helper = new Dom_Document_Helper( $html );
+		$this->assertEquals( 'some-class', $dom_document_helper->get_attribute_value_by_tag_name( 'p', 'class' ) );
+		$this->assertNull( $dom_document_helper->get_attribute_value_by_tag_name( 'span', 'class' ) );
 	}
 }