diff --git a/packages/php/email-editor/tests/integration/Engine/Email_Editor_Test.php b/packages/php/email-editor/tests/integration/Engine/Email_Editor_Test.php
index f7143f1187..f5c9f3c5c9 100644
--- a/packages/php/email-editor/tests/integration/Engine/Email_Editor_Test.php
+++ b/packages/php/email-editor/tests/integration/Engine/Email_Editor_Test.php
@@ -1,36 +1,62 @@
-<?php declare(strict_types = 1);
+<?php
+/**
+ * This file is part of the MailPoet plugin.
+ *
+ * @package MailPoet\EmailEditor
+ */
 
+declare(strict_types = 1);
 namespace MailPoet\EmailEditor\Engine;
 
+/**
+ * Integration test for Email_Editor class
+ */
 class Email_Editor_Test extends \MailPoetTest {
-	/** @var Email_Editor */
-	private $emailEditor;
+	/**
+	 * Email editor instance
+	 *
+	 * @var Email_Editor
+	 */
+	private $email_editor;
 
-	/** @var callable */
-	private $postRegisterCallback;
+	/**
+	 * Callback to register custom post type
+	 *
+	 * @var callable
+	 */
+	private $post_register_callback;
 
+	/**
+	 * Set up before each test
+	 */
 	public function _before() {
 		parent::_before();
-		$this->emailEditor          = $this->di_container->get( Email_Editor::class );
-		$this->postRegisterCallback = function ( $postTypes ) {
-			$postTypes[] = array(
+		$this->email_editor           = $this->di_container->get( Email_Editor::class );
+		$this->post_register_callback = function ( $post_types ) {
+			$post_types[] = array(
 				'name' => 'custom_email_type',
 				'args' => array(),
 				'meta' => array(),
 			);
-			return $postTypes;
+			return $post_types;
 		};
-		add_filter( 'mailpoet_email_editor_post_types', $this->postRegisterCallback );
-		$this->emailEditor->initialize();
+		add_filter( 'mailpoet_email_editor_post_types', $this->post_register_callback );
+		$this->email_editor->initialize();
 	}
 
+	/**
+	 * Test if the email register custom post type
+	 */
 	public function testItRegistersCustomPostTypeAddedViaHook() {
-		$postTypes = get_post_types();
-		$this->assertArrayHasKey( 'custom_email_type', $postTypes );
+		$post_types = get_post_types();
+		$this->assertArrayHasKey( 'custom_email_type', $post_types );
 	}
 
+	/**
+	 * Clean up after each test
+	 */
 	public function _after() {
 		parent::_after();
-		remove_filter( 'mailpoet_email_editor_post_types', $this->postRegisterCallback );
+		remove_filter( 'mailpoet_email_editor_post_types', $this->post_register_callback );
 	}
 }
diff --git a/packages/php/email-editor/tests/integration/Engine/Renderer/ContentRenderer/Blocks_Registry_Test.php b/packages/php/email-editor/tests/integration/Engine/Renderer/ContentRenderer/Blocks_Registry_Test.php
index b5d9080153..981e64dc22 100644
--- a/packages/php/email-editor/tests/integration/Engine/Renderer/ContentRenderer/Blocks_Registry_Test.php
+++ b/packages/php/email-editor/tests/integration/Engine/Renderer/ContentRenderer/Blocks_Registry_Test.php
@@ -1,33 +1,58 @@
-<?php declare(strict_types = 1);
+<?php
+/**
+ * This file is part of the MailPoet plugin.
+ *
+ * @package MailPoet\EmailEditor
+ */
 
+declare(strict_types = 1);
 namespace MailPoet\EmailEditor\Engine\Renderer\ContentRenderer;
 
 use MailPoet\EmailEditor\Integrations\Core\Renderer\Blocks\Text;
 
 require_once __DIR__ . '/Dummy_Block_Renderer.php';
 
+/**
+ * Integration test for Blocks_Registry
+ */
 class Blocks_Registry_Test extends \MailPoetTest {
 
-	/** @var Blocks_Registry */
+	/**
+	 * Instance of Blocks_Registry
+	 *
+	 * @var Blocks_Registry
+	 */
 	private $registry;
 
+	/**
+	 * Set up before each test.
+	 */
 	public function _before() {
 		parent::_before();
 		$this->registry = $this->di_container->get( Blocks_Registry::class );
 	}
 
+	/**
+	 * Test it returns null for unknown renderer.
+	 */
 	public function testItReturnsNullForUnknownRenderer() {
-		$storedRenderer = $this->registry->get_block_renderer( 'test' );
-		verify( $storedRenderer )->null();
+		$stored_renderer = $this->registry->get_block_renderer( 'test' );
+		verify( $stored_renderer )->null();
 	}
 
+	/**
+	 * Test it stores added renderer.
+	 */
 	public function testItStoresAddedRenderer() {
 		$renderer = new Text();
 		$this->registry->add_block_renderer( 'test', $renderer );
-		$storedRenderer = $this->registry->get_block_renderer( 'test' );
-		verify( $storedRenderer )->equals( $renderer );
+		$stored_renderer = $this->registry->get_block_renderer( 'test' );
+		verify( $stored_renderer )->equals( $renderer );
 	}
 
+	/**
+	 * Test it reports which renderers are registered.
+	 */
 	public function testItReportsWhichRenderersAreRegistered() {
 		$renderer = new Text();
 		$this->registry->add_block_renderer( 'test', $renderer );
diff --git a/packages/php/email-editor/tests/integration/Engine/Renderer/ContentRenderer/Content_Renderer_Test.php b/packages/php/email-editor/tests/integration/Engine/Renderer/ContentRenderer/Content_Renderer_Test.php
index 9566ed2bba..7211dd4a0a 100644
--- a/packages/php/email-editor/tests/integration/Engine/Renderer/ContentRenderer/Content_Renderer_Test.php
+++ b/packages/php/email-editor/tests/integration/Engine/Renderer/ContentRenderer/Content_Renderer_Test.php
@@ -1,5 +1,11 @@
-<?php declare(strict_types = 1);
+<?php
+/**
+ * This file is part of the MailPoet plugin.
+ *
+ * @package MailPoet\EmailEditor
+ */
 
+declare(strict_types = 1);
 namespace MailPoet\EmailEditor\Engine\Renderer\ContentRenderer;
 
 use MailPoet\EmailEditor\Engine\Email_Editor;
@@ -7,44 +13,71 @@ use MailPoet\EmailEditor\Integrations\MailPoet\Blocks\BlockTypesController;
 
 require_once __DIR__ . '/Dummy_Block_Renderer.php';
 
+/**
+ * Integration test for Content_Renderer
+ */
 class Content_Renderer_Test extends \MailPoetTest {
+	/**
+	 * Instance of the renderer.
+	 *
+	 * @var Content_Renderer
+	 */
 	private Content_Renderer $renderer;
+	/**
+	 * Instance of the email post.
+	 *
+	 * @var \WP_Post
+	 */
+	private \WP_Post $email_post;
 
-	private \WP_Post $emailPost;
-
+	/**
+	 * Set up before each test.
+	 */
 	public function _before(): void {
 		parent::_before();
 		$this->di_container->get( Email_Editor::class )->initialize();
 		$this->di_container->get( BlockTypesController::class )->initialize();
-		$this->renderer  = $this->di_container->get( Content_Renderer::class );
-		$this->emailPost = $this->tester->create_post(
+		$this->renderer   = $this->di_container->get( Content_Renderer::class );
+		$this->email_post = $this->tester->create_post(
 			array(
 				'post_content' => '<!-- wp:paragraph --><p>Hello!</p><!-- /wp:paragraph -->',
 			)
 		);
 	}
 
+	/**
+	 * Test it renders the content.
+	 */
 	public function testItRendersContent(): void {
 		$template          = new \WP_Block_Template();
 		$template->id      = 'template-id';
 		$template->content = '<!-- wp:core/post-content /-->';
 		$content           = $this->renderer->render(
-			$this->emailPost,
+			$this->email_post,
 			$template
 		);
 		verify( $content )->stringContainsString( 'Hello!' );
 	}
 
+	/**
+	 * Test it inlines content styles.
+	 */
 	public function testItInlinesContentStyles(): void {
 		$template          = new \WP_Block_Template();
 		$template->id      = 'template-id';
 		$template->content = '<!-- wp:core/post-content /-->';
-		$rendered          = $this->renderer->render( $this->emailPost, $template );
-		$paragraphStyles   = $this->getStylesValueForTag( $rendered, 'p' );
-		verify( $paragraphStyles )->stringContainsString( 'margin: 0' );
-		verify( $paragraphStyles )->stringContainsString( 'display: block' );
+		$rendered          = $this->renderer->render( $this->email_post, $template );
+		$paragraph_styles  = $this->getStylesValueForTag( $rendered, 'p' );
+		verify( $paragraph_styles )->stringContainsString( 'margin: 0' );
+		verify( $paragraph_styles )->stringContainsString( 'display: block' );
 	}
 
+	/**
+	 * Get the value of the style attribute for a given tag in the HTML.
+	 *
+	 * @param string $html HTML content.
+	 * @param string $tag Tag name.
+	 */
 	private function getStylesValueForTag( $html, $tag ): ?string {
 		$html = new \WP_HTML_Tag_Processor( $html );
 		if ( $html->next_tag( $tag ) ) {
diff --git a/packages/php/email-editor/tests/integration/Engine/Renderer/ContentRenderer/Dummy_Block_Renderer.php b/packages/php/email-editor/tests/integration/Engine/Renderer/ContentRenderer/Dummy_Block_Renderer.php
index df73383863..b7342da0d9 100644
--- a/packages/php/email-editor/tests/integration/Engine/Renderer/ContentRenderer/Dummy_Block_Renderer.php
+++ b/packages/php/email-editor/tests/integration/Engine/Renderer/ContentRenderer/Dummy_Block_Renderer.php
@@ -1,10 +1,27 @@
-<?php declare(strict_types = 1);
+<?php
+/**
+ * This file is part of the MailPoet plugin.
+ *
+ * @package MailPoet\EmailEditor
+ */
 
+declare(strict_types = 1);
 namespace MailPoet\EmailEditor\Engine\Renderer\ContentRenderer;
 
 use MailPoet\EmailEditor\Engine\Settings_Controller;
 
+/**
+ * Dummy block renderer for testing purposes.
+ */
 class Dummy_Block_Renderer implements Block_Renderer {
+	/**
+	 * Renders the block.
+	 *
+	 * @param string              $block_content The block content.
+	 * @param array               $parsed_block The parsed block.
+	 * @param Settings_Controller $settings_controller The settings controller.
+	 * @return string
+	 */
 	public function render( string $block_content, array $parsed_block, Settings_Controller $settings_controller ): string {
 		return $parsed_block['innerHtml'];
 	}
diff --git a/packages/php/email-editor/tests/integration/Engine/Renderer/ContentRenderer/Layout/Flex_Layout_Renderer_Test.php b/packages/php/email-editor/tests/integration/Engine/Renderer/ContentRenderer/Layout/Flex_Layout_Renderer_Test.php
index 27dff1c1d5..362b7c3345 100644
--- a/packages/php/email-editor/tests/integration/Engine/Renderer/ContentRenderer/Layout/Flex_Layout_Renderer_Test.php
+++ b/packages/php/email-editor/tests/integration/Engine/Renderer/ContentRenderer/Layout/Flex_Layout_Renderer_Test.php
@@ -1,5 +1,11 @@
-<?php declare(strict_types = 1);
+<?php
+/**
+ * This file is part of the MailPoet plugin.
+ *
+ * @package MailPoet\EmailEditor
+ */
 
+declare(strict_types = 1);
 namespace MailPoet\EmailEditor\Engine\Renderer\ContentRenderer\Layout;
 
 use MailPoet\EmailEditor\Engine\Renderer\ContentRenderer\Dummy_Block_Renderer;
@@ -7,14 +13,28 @@ use MailPoet\EmailEditor\Engine\Settings_Controller;
 
 require_once __DIR__ . '/../Dummy_Block_Renderer.php';
 
+/**
+ * Integration test for Flex_Layout_Renderer
+ */
 class Flex_Layout_Renderer_Test extends \MailPoetTest {
 
-	/** @var Flex_Layout_Renderer */
+	/**
+	 * Instance of the renderer.
+	 *
+	 * @var Flex_Layout_Renderer
+	 */
 	private $renderer;
 
-	/** @var Settings_Controller */
-	private $settingsController;
+	/**
+	 * Instance of the settings controller.
+	 *
+	 * @var Settings_Controller
+	 */
+	private $settings_controller;
 
+	/**
+	 * Set up before each test.
+	 */
 	public function _before(): void {
 		parent::_before();
 		$this->settings_controller = $this->di_container->get( Settings_Controller::class );
@@ -23,8 +43,11 @@ class Flex_Layout_Renderer_Test extends \MailPoetTest {
 		add_filter( 'render_block', array( $this, 'renderDummyBlock' ), 10, 2 );
 	}
 
+	/**
+	 * Test it renders inner blocks.
+	 */
 	public function testItRendersInnerBlocks(): void {
-		$parsedBlock = array(
+		$parsed_block = array(
 			'innerBlocks' => array(
 				array(
 					'blockName' => 'dummy/block',
@@ -37,13 +60,16 @@ class Flex_Layout_Renderer_Test extends \MailPoetTest {
 			),
 			'email_attrs' => array(),
 		);
-		$output      = $this->renderer->render_inner_blocks_in_layout( $parsedBlock, $this->settingsController );
+		$output       = $this->renderer->render_inner_blocks_in_layout( $parsed_block, $this->settings_controller );
 		verify( $output )->stringContainsString( 'Dummy 1' );
 		verify( $output )->stringContainsString( 'Dummy 2' );
 	}
 
+	/**
+	 * Test it handles justifying the content.
+	 */
 	public function testItHandlesJustification(): void {
-		$parsedBlock = array(
+		$parsed_block = array(
 			'innerBlocks' => array(
 				array(
 					'blockName' => 'dummy/block',
@@ -52,24 +78,27 @@ class Flex_Layout_Renderer_Test extends \MailPoetTest {
 			),
 			'email_attrs' => array(),
 		);
-		// Default justification is left
-		$output = $this->renderer->render_inner_blocks_in_layout( $parsedBlock, $this->settingsController );
+		// Default justification is left.
+		$output = $this->renderer->render_inner_blocks_in_layout( $parsed_block, $this->settings_controller );
 		verify( $output )->stringContainsString( 'text-align: left' );
 		verify( $output )->stringContainsString( 'align="left"' );
-		// Right justification
-		$parsedBlock['attrs']['layout']['justifyContent'] = 'right';
-		$output = $this->renderer->render_inner_blocks_in_layout( $parsedBlock, $this->settingsController );
+		// Right justification.
+		$parsed_block['attrs']['layout']['justifyContent'] = 'right';
+		$output = $this->renderer->render_inner_blocks_in_layout( $parsed_block, $this->settings_controller );
 		verify( $output )->stringContainsString( 'text-align: right' );
 		verify( $output )->stringContainsString( 'align="right"' );
-		// Center justification
-		$parsedBlock['attrs']['layout']['justifyContent'] = 'center';
-		$output = $this->renderer->render_inner_blocks_in_layout( $parsedBlock, $this->settingsController );
+		// Center justification.
+		$parsed_block['attrs']['layout']['justifyContent'] = 'center';
+		$output = $this->renderer->render_inner_blocks_in_layout( $parsed_block, $this->settings_controller );
 		verify( $output )->stringContainsString( 'text-align: center' );
 		verify( $output )->stringContainsString( 'align="center"' );
 	}
 
+	/**
+	 * Test it escapes attributes.
+	 */
 	public function testItEscapesAttributes(): void {
-		$parsedBlock                                      = array(
+		$parsed_block                                      = array(
 			'innerBlocks' => array(
 				array(
 					'blockName' => 'dummy/block',
@@ -78,13 +107,16 @@ class Flex_Layout_Renderer_Test extends \MailPoetTest {
 			),
 			'email_attrs' => array(),
 		);
-		$parsedBlock['attrs']['layout']['justifyContent'] = '"> <script>alert("XSS")</script><div style="text-align: right';
-		$output = $this->renderer->render_inner_blocks_in_layout( $parsedBlock, $this->settingsController );
+		$parsed_block['attrs']['layout']['justifyContent'] = '"> <script>alert("XSS")</script><div style="text-align: right';
+		$output = $this->renderer->render_inner_blocks_in_layout( $parsed_block, $this->settings_controller );
 		verify( $output )->stringNotContainsString( '<script>alert("XSS")</script>' );
 	}
 
+	/**
+	 * Test that the renderer computes proper widths for reasonable settings.
+	 */
 	public function testInComputesProperWidthsForReasonableSettings(): void {
-		$parsedBlock = array(
+		$parsed_block = array(
 			'innerBlocks' => array(),
 			'email_attrs' => array(
 				'width' => '640px',
@@ -92,7 +124,7 @@ class Flex_Layout_Renderer_Test extends \MailPoetTest {
 		);
 
 		// 50% and 25%
-		$parsedBlock['innerBlocks'] = array(
+		$parsed_block['innerBlocks'] = array(
 			array(
 				'blockName' => 'dummy/block',
 				'innerHtml' => 'Dummy 1',
@@ -104,13 +136,13 @@ class Flex_Layout_Renderer_Test extends \MailPoetTest {
 				'attrs'     => array( 'width' => '25' ),
 			),
 		);
-		$output                     = $this->renderer->render_inner_blocks_in_layout( $parsedBlock, $this->settingsController );
-		$flexItems                  = $this->getFlexItemsFromOutput( $output );
-		verify( $flexItems[0] )->stringContainsString( 'width:312px;' );
-		verify( $flexItems[1] )->stringContainsString( 'width:148px;' );
+		$output                      = $this->renderer->render_inner_blocks_in_layout( $parsed_block, $this->settings_controller );
+		$flex_items                  = $this->getFlexItemsFromOutput( $output );
+		verify( $flex_items[0] )->stringContainsString( 'width:312px;' );
+		verify( $flex_items[1] )->stringContainsString( 'width:148px;' );
 
 		// 25% and 25% and auto
-		$parsedBlock['innerBlocks'] = array(
+		$parsed_block['innerBlocks'] = array(
 			array(
 				'blockName' => 'dummy/block',
 				'innerHtml' => 'Dummy 1',
@@ -127,14 +159,14 @@ class Flex_Layout_Renderer_Test extends \MailPoetTest {
 				'attrs'     => array(),
 			),
 		);
-		$output                     = $this->renderer->render_inner_blocks_in_layout( $parsedBlock, $this->settingsController );
-		$flexItems                  = $this->getFlexItemsFromOutput( $output );
-		verify( $flexItems[0] )->stringContainsString( 'width:148px;' );
-		verify( $flexItems[1] )->stringContainsString( 'width:148px;' );
-		verify( $flexItems[2] )->stringNotContainsString( 'width:' );
+		$output                      = $this->renderer->render_inner_blocks_in_layout( $parsed_block, $this->settings_controller );
+		$flex_items                  = $this->getFlexItemsFromOutput( $output );
+		verify( $flex_items[0] )->stringContainsString( 'width:148px;' );
+		verify( $flex_items[1] )->stringContainsString( 'width:148px;' );
+		verify( $flex_items[2] )->stringNotContainsString( 'width:' );
 
 		// 50% and 50%
-		$parsedBlock['innerBlocks'] = array(
+		$parsed_block['innerBlocks'] = array(
 			array(
 				'blockName' => 'dummy/block',
 				'innerHtml' => 'Dummy 1',
@@ -146,14 +178,17 @@ class Flex_Layout_Renderer_Test extends \MailPoetTest {
 				'attrs'     => array( 'width' => '50' ),
 			),
 		);
-		$output                     = $this->renderer->render_inner_blocks_in_layout( $parsedBlock, $this->settingsController );
-		$flexItems                  = $this->getFlexItemsFromOutput( $output );
-		verify( $flexItems[0] )->stringContainsString( 'width:312px;' );
-		verify( $flexItems[1] )->stringContainsString( 'width:312px;' );
+		$output                      = $this->renderer->render_inner_blocks_in_layout( $parsed_block, $this->settings_controller );
+		$flex_items                  = $this->getFlexItemsFromOutput( $output );
+		verify( $flex_items[0] )->stringContainsString( 'width:312px;' );
+		verify( $flex_items[1] )->stringContainsString( 'width:312px;' );
 	}
 
+	/**
+	 * Test that the renderer computes proper widths for strange settings values.
+	 */
 	public function testInComputesWidthsForStrangeSettingsValues(): void {
-		$parsedBlock = array(
+		$parsed_block = array(
 			'innerBlocks' => array(),
 			'email_attrs' => array(
 				'width' => '640px',
@@ -161,7 +196,7 @@ class Flex_Layout_Renderer_Test extends \MailPoetTest {
 		);
 
 		// 100% and 25%
-		$parsedBlock['innerBlocks'] = array(
+		$parsed_block['innerBlocks'] = array(
 			array(
 				'blockName' => 'dummy/block',
 				'innerHtml' => 'Dummy 1',
@@ -173,13 +208,13 @@ class Flex_Layout_Renderer_Test extends \MailPoetTest {
 				'attrs'     => array( 'width' => '25' ),
 			),
 		);
-		$output                     = $this->renderer->render_inner_blocks_in_layout( $parsedBlock, $this->settingsController );
-		$flexItems                  = $this->getFlexItemsFromOutput( $output );
-		verify( $flexItems[0] )->stringContainsString( 'width:508px;' );
-		verify( $flexItems[1] )->stringContainsString( 'width:105px;' );
+		$output                      = $this->renderer->render_inner_blocks_in_layout( $parsed_block, $this->settings_controller );
+		$flex_items                  = $this->getFlexItemsFromOutput( $output );
+		verify( $flex_items[0] )->stringContainsString( 'width:508px;' );
+		verify( $flex_items[1] )->stringContainsString( 'width:105px;' );
 
 		// 100% and 100%
-		$parsedBlock['innerBlocks'] = array(
+		$parsed_block['innerBlocks'] = array(
 			array(
 				'blockName' => 'dummy/block',
 				'innerHtml' => 'Dummy 1',
@@ -191,13 +226,13 @@ class Flex_Layout_Renderer_Test extends \MailPoetTest {
 				'attrs'     => array( 'width' => '100' ),
 			),
 		);
-		$output                     = $this->renderer->render_inner_blocks_in_layout( $parsedBlock, $this->settingsController );
-		$flexItems                  = $this->getFlexItemsFromOutput( $output );
-		verify( $flexItems[0] )->stringContainsString( 'width:312px;' );
-		verify( $flexItems[1] )->stringContainsString( 'width:312px;' );
+		$output                      = $this->renderer->render_inner_blocks_in_layout( $parsed_block, $this->settings_controller );
+		$flex_items                  = $this->getFlexItemsFromOutput( $output );
+		verify( $flex_items[0] )->stringContainsString( 'width:312px;' );
+		verify( $flex_items[1] )->stringContainsString( 'width:312px;' );
 
 		// 100% and auto
-		$parsedBlock['innerBlocks'] = array(
+		$parsed_block['innerBlocks'] = array(
 			array(
 				'blockName' => 'dummy/block',
 				'innerHtml' => 'Dummy 1',
@@ -209,23 +244,38 @@ class Flex_Layout_Renderer_Test extends \MailPoetTest {
 				'attrs'     => array(),
 			),
 		);
-		$output                     = $this->renderer->render_inner_blocks_in_layout( $parsedBlock, $this->settingsController );
-		$flexItems                  = $this->getFlexItemsFromOutput( $output );
-		verify( $flexItems[0] )->stringContainsString( 'width:508px;' );
-		verify( $flexItems[1] )->stringNotContainsString( 'width:' );
+		$output                      = $this->renderer->render_inner_blocks_in_layout( $parsed_block, $this->settings_controller );
+		$flex_items                  = $this->getFlexItemsFromOutput( $output );
+		verify( $flex_items[0] )->stringContainsString( 'width:508px;' );
+		verify( $flex_items[1] )->stringNotContainsString( 'width:' );
 	}
 
+	/**
+	 * Get flex items from the output.
+	 *
+	 * @param string $output Output.
+	 */
 	private function getFlexItemsFromOutput( string $output ): array {
 		$matches = array();
 		preg_match_all( '/<td class="layout-flex-item" style="(.*)">/', $output, $matches );
 		return explode( '><', $matches[0][0] ?? array() );
 	}
 
-	public function renderDummyBlock( $blockContent, $parsedBlock ): string {
-		$dummyRenderer = new Dummy_Block_Renderer();
-		return $dummyRenderer->render( $blockContent, $parsedBlock, $this->settingsController );
+	/**
+	 * Render a dummy block.
+	 *
+	 * @param string $block_content Block content.
+	 * @param array  $parsed_block Parsed block data.
+	 * @return string
+	 */
+	public function renderDummyBlock( $block_content, $parsed_block ): string {
+		$dummy_renderer = new Dummy_Block_Renderer();
+		return $dummy_renderer->render( $block_content, $parsed_block, $this->settings_controller );
 	}
 
+	/**
+	 * Clean up after each test.
+	 */
 	public function _after(): void {
 		parent::_after();
 		unregister_block_type( 'dummy/block' );
diff --git a/packages/php/email-editor/tests/integration/Engine/Renderer/Renderer_Test.php b/packages/php/email-editor/tests/integration/Engine/Renderer/Renderer_Test.php
index 30480254ae..b11724df41 100644
--- a/packages/php/email-editor/tests/integration/Engine/Renderer/Renderer_Test.php
+++ b/packages/php/email-editor/tests/integration/Engine/Renderer/Renderer_Test.php
@@ -1,21 +1,42 @@
-<?php declare(strict_types = 1);
+<?php
+/**
+ * This file is part of the MailPoet plugin.
+ *
+ * @package MailPoet\EmailEditor
+ */
 
+declare(strict_types = 1);
 namespace MailPoet\EmailEditor\Engine\Renderer;
 
 use MailPoet\EmailEditor\Engine\Email_Editor;
 use MailPoet\EmailEditor\Engine\Settings_Controller;
 use MailPoet\EmailEditor\Engine\Theme_Controller;
 
+/**
+ * Integration test for Renderer
+ */
 class Renderer_Test extends \MailPoetTest {
+	/**
+	 * The renderer.
+	 *
+	 * @var Renderer
+	 */
 	private Renderer $renderer;
+	/**
+	 * The email post.
+	 *
+	 * @var \WP_Post
+	 */
+	private \WP_Post $email_post;
 
-	private \WP_Post $emailPost;
-
+	/**
+	 * Set up before each test.
+	 */
 	public function _before(): void {
 		parent::_before();
 		$this->di_container->get( Email_Editor::class )->initialize();
-		$this->renderer = $this->di_container->get( Renderer::class );
-		$styles         = array(
+		$this->renderer  = $this->di_container->get( Renderer::class );
+		$styles          = array(
 			'spacing'    => array(
 				'padding' => array(
 					'bottom' => '4px',
@@ -31,36 +52,39 @@ class Renderer_Test extends \MailPoetTest {
 				'background' => '#123456',
 			),
 		);
-		$themeJsonMock  = $this->createMock( \WP_Theme_JSON::class );
-		$themeJsonMock->method( 'get_data' )->willReturn(
+		$theme_json_mock = $this->createMock( \WP_Theme_JSON::class );
+		$theme_json_mock->method( 'get_data' )->willReturn(
 			array(
 				'styles' => $styles,
 			)
 		);
-		$settingsControllerMock = $this->createMock( Settings_Controller::class );
-		$settingsControllerMock->method( 'get_email_styles' )->willReturn( $styles );
-		$themeControllerMock = $this->createMock( Theme_Controller::class );
-		$themeControllerMock->method( 'get_theme' )->willReturn( $themeJsonMock );
-		$themeControllerMock->method( 'get_styles' )->willReturn( $styles );
-		$themeControllerMock->method( 'get_layout_settings' )->willReturn( array( 'contentSize' => '660px' ) );
+		$settings_controller_mock = $this->createMock( Settings_Controller::class );
+		$settings_controller_mock->method( 'get_email_styles' )->willReturn( $styles );
+		$theme_controller_mock = $this->createMock( Theme_Controller::class );
+		$theme_controller_mock->method( 'get_theme' )->willReturn( $theme_json_mock );
+		$theme_controller_mock->method( 'get_styles' )->willReturn( $styles );
+		$theme_controller_mock->method( 'get_layout_settings' )->willReturn( array( 'contentSize' => '660px' ) );
 
-		$this->renderer  = $this->getServiceWithOverrides(
+		$this->renderer   = $this->getServiceWithOverrides(
 			Renderer::class,
 			array(
-				'settingsController' => $settingsControllerMock,
-				'themeController'    => $themeControllerMock,
+				'settingsController' => $settings_controller_mock,
+				'themeController'    => $theme_controller_mock,
 			)
 		);
-		$this->emailPost = $this->tester->create_post(
+		$this->email_post = $this->tester->create_post(
 			array(
 				'post_content' => '<!-- wp:paragraph --><p>Hello!</p><!-- /wp:paragraph -->',
 			)
 		);
 	}
 
+	/**
+	 * Test it renders template with content.
+	 */
 	public function testItRendersTemplateWithContent(): void {
 		$rendered = $this->renderer->render(
-			$this->emailPost,
+			$this->email_post,
 			'Subject',
 			'Preheader content',
 			'en',
@@ -75,31 +99,40 @@ class Renderer_Test extends \MailPoetTest {
 		verify( $rendered['text'] )->stringContainsString( 'Hello!' );
 	}
 
+	/**
+	 * Test it inlines styles.
+	 */
 	public function testItInlinesStyles(): void {
-		$stylesCallback = function ( $styles ) {
+		$styles_callback = function ( $styles ) {
 			return $styles . 'body { color: pink; }';
 		};
-		add_filter( 'mailpoet_email_renderer_styles', $stylesCallback );
-		$rendered = $this->renderer->render( $this->emailPost, 'Subject', '', 'en' );
+		add_filter( 'mailpoet_email_renderer_styles', $styles_callback );
+		$rendered = $this->renderer->render( $this->email_post, 'Subject', '', 'en' );
 		$style    = $this->getStylesValueForTag( $rendered['html'], array( 'tag_name' => 'body' ) );
 		verify( $style )->stringContainsString( 'color: pink' );
-		remove_filter( 'mailpoet_email_renderer_styles', $stylesCallback );
+		remove_filter( 'mailpoet_email_renderer_styles', $styles_callback );
 	}
 
+	/**
+	 * Test it inlines body styles.
+	 */
 	public function testItInlinesBodyStyles(): void {
-		$rendered = $this->renderer->render( $this->emailPost, 'Subject', '', 'en' );
+		$rendered = $this->renderer->render( $this->email_post, 'Subject', '', 'en' );
 		$style    = $this->getStylesValueForTag( $rendered['html'], array( 'tag_name' => 'body' ) );
 		verify( $style )->stringContainsString( 'margin: 0; padding: 0;' );
 	}
 
+	/**
+	 * Test it inlines wrapper styles.
+	 */
 	public function testItInlinesWrappersStyles(): void {
-		$rendered = $this->renderer->render( $this->emailPost, 'Subject', '', 'en' );
+		$rendered = $this->renderer->render( $this->email_post, 'Subject', '', 'en' );
 
-		// Verify body element styles
+		// Verify body element styles.
 		$style = $this->getStylesValueForTag( $rendered['html'], array( 'tag_name' => 'body' ) );
 		verify( $style )->stringContainsString( 'background-color: #123456' );
 
-		// Verify layout element styles
+		// Verify layout element styles.
 		$doc = new \DOMDocument();
 		$doc->loadHTML( $rendered['html'] );
 		$xpath   = new \DOMXPath( $doc );
@@ -119,6 +152,13 @@ class Renderer_Test extends \MailPoetTest {
 		verify( $style )->stringContainsString( 'max-width: 660px;' );
 	}
 
+	/**
+	 * Returns the value of the style attribute for the first tag that matches the query.
+	 *
+	 * @param string $html HTML content.
+	 * @param array  $query Query to find the tag.
+	 * @return string|null
+	 */
 	private function getStylesValueForTag( string $html, array $query ): ?string {
 		$html = new \WP_HTML_Tag_Processor( $html );
 		if ( $html->next_tag( $query ) ) {
diff --git a/packages/php/email-editor/tests/integration/Engine/Theme_Controller_Test.php b/packages/php/email-editor/tests/integration/Engine/Theme_Controller_Test.php
index 66c4020b25..4b01d21669 100644
--- a/packages/php/email-editor/tests/integration/Engine/Theme_Controller_Test.php
+++ b/packages/php/email-editor/tests/integration/Engine/Theme_Controller_Test.php
@@ -1,18 +1,38 @@
-<?php declare(strict_types = 1);
+<?php
+/**
+ * This file is part of the MailPoet plugin.
+ *
+ * @package MailPoet\EmailEditor
+ */
 
+declare(strict_types = 1);
 namespace MailPoet\EmailEditor\Engine;
 
+/**
+ * Integration test for Theme_Controller class
+ */
 class Theme_Controller_Test extends \MailPoetTest {
-	private Theme_Controller $themeController;
+	/**
+	 * Theme controller instance
+	 *
+	 * @var Theme_Controller
+	 */
+	private Theme_Controller $theme_controller;
 
+	/**
+	 * Set up before each test
+	 */
 	public function _before() {
 		parent::_before();
-		$this->themeController = $this->di_container->get( Theme_Controller::class );
+		$this->theme_controller = $this->di_container->get( Theme_Controller::class );
 	}
 
+	/**
+	 * Test it generates css styles for renderer
+	 */
 	public function testItGeneratesCssStylesForRenderer() {
-		$css = $this->themeController->get_stylesheet_for_rendering();
-		// Font families
+		$css = $this->theme_controller->get_stylesheet_for_rendering();
+		// Font families.
 		verify( $css )->stringContainsString( '.has-arial-font-family' );
 		verify( $css )->stringContainsString( '.has-comic-sans-ms-font-family' );
 		verify( $css )->stringContainsString( '.has-courier-new-font-family' );
@@ -41,13 +61,13 @@ class Theme_Controller_Test extends \MailPoetTest {
 		verify( $css )->stringContainsString( '.has-large-font-size' );
 		verify( $css )->stringContainsString( '.has-x-large-font-size' );
 
-		// Font sizes
+		// Font sizes.
 		verify( $css )->stringContainsString( '.has-small-font-size' );
 		verify( $css )->stringContainsString( '.has-medium-font-size' );
 		verify( $css )->stringContainsString( '.has-large-font-size' );
 		verify( $css )->stringContainsString( '.has-x-large-font-size' );
 
-		// Colors
+		// Colors.
 		verify( $css )->stringContainsString( '.has-black-color' );
 		verify( $css )->stringContainsString( '.has-black-background-color' );
 		verify( $css )->stringContainsString( '.has-black-border-color' );
@@ -64,37 +84,49 @@ class Theme_Controller_Test extends \MailPoetTest {
 		}
 	}
 
+	/**
+	 * Test if the theme controller translates font size slug to font size value
+	 */
 	public function testItCanTranslateFontSizeSlug() {
-		verify( $this->themeController->translate_slug_to_font_size( 'small' ) )->equals( '13px' );
-		verify( $this->themeController->translate_slug_to_font_size( 'medium' ) )->equals( '16px' );
-		verify( $this->themeController->translate_slug_to_font_size( 'large' ) )->equals( '28px' );
-		verify( $this->themeController->translate_slug_to_font_size( 'x-large' ) )->equals( '42px' );
-		verify( $this->themeController->translate_slug_to_font_size( 'unknown' ) )->equals( 'unknown' );
+		verify( $this->theme_controller->translate_slug_to_font_size( 'small' ) )->equals( '13px' );
+		verify( $this->theme_controller->translate_slug_to_font_size( 'medium' ) )->equals( '16px' );
+		verify( $this->theme_controller->translate_slug_to_font_size( 'large' ) )->equals( '28px' );
+		verify( $this->theme_controller->translate_slug_to_font_size( 'x-large' ) )->equals( '42px' );
+		verify( $this->theme_controller->translate_slug_to_font_size( 'unknown' ) )->equals( 'unknown' );
 	}
 
+	/**
+	 * Test if the theme controller translates font family slug to font family name
+	 */
 	public function testItCanTranslateColorSlug() {
-		verify( $this->themeController->translate_slug_to_color( 'black' ) )->equals( '#000000' );
-		verify( $this->themeController->translate_slug_to_color( 'white' ) )->equals( '#ffffff' );
-		verify( $this->themeController->translate_slug_to_color( 'cyan-bluish-gray' ) )->equals( '#abb8c3' );
-		verify( $this->themeController->translate_slug_to_color( 'pale-pink' ) )->equals( '#f78da7' );
+		verify( $this->theme_controller->translate_slug_to_color( 'black' ) )->equals( '#000000' );
+		verify( $this->theme_controller->translate_slug_to_color( 'white' ) )->equals( '#ffffff' );
+		verify( $this->theme_controller->translate_slug_to_color( 'cyan-bluish-gray' ) )->equals( '#abb8c3' );
+		verify( $this->theme_controller->translate_slug_to_color( 'pale-pink' ) )->equals( '#f78da7' );
 		$this->checkCorrectThemeConfiguration();
 		if ( wp_get_theme()->get( 'Name' ) === 'Twenty Twenty-One' ) {
-			verify( $this->themeController->translate_slug_to_color( 'yellow' ) )->equals( '#eeeadd' );
+			verify( $this->theme_controller->translate_slug_to_color( 'yellow' ) )->equals( '#eeeadd' );
 		}
 	}
 
+	/**
+	 * Test if the theme controller returns correct color palette
+	 */
 	public function testItLoadsColorPaletteFromSiteTheme() {
 		$this->checkCorrectThemeConfiguration();
-		$settings = $this->themeController->get_settings();
+		$settings = $this->theme_controller->get_settings();
 		if ( wp_get_theme()->get( 'Name' ) === 'Twenty Twenty-One' ) {
 			verify( $settings['color']['palette']['theme'] )->notEmpty();
 		}
 	}
 
+	/**
+	 * Test if the theme controller returns correct preset variables map
+	 */
 	public function testItReturnsCorrectPresetVariablesMap() {
-		$variableMap = $this->themeController->get_variables_values_map();
-		verify( $variableMap['--wp--preset--color--black'] )->equals( '#000000' );
-		verify( $variableMap['--wp--preset--spacing--20'] )->equals( '20px' );
+		$variable_map = $this->theme_controller->get_variables_values_map();
+		verify( $variable_map['--wp--preset--color--black'] )->equals( '#000000' );
+		verify( $variable_map['--wp--preset--spacing--20'] )->equals( '20px' );
 	}
 
 	/**
@@ -103,8 +135,8 @@ class Theme_Controller_Test extends \MailPoetTest {
 	 * to prevent silent failures in case we change theme configuration in the test environment.
 	 */
 	private function checkCorrectThemeConfiguration() {
-		$expectedThemes = array( 'Twenty Twenty-One' );
-		if ( ! in_array( wp_get_theme()->get( 'Name' ), $expectedThemes ) ) {
+		$expected_themes = array( 'Twenty Twenty-One' );
+		if ( ! in_array( wp_get_theme()->get( 'Name' ), $expected_themes, true ) ) {
 			$this->fail( 'Test depends on using Twenty Twenty-One or Twenty Nineteen theme. If you changed the theme, please update the test.' );
 		}
 	}