diff --git a/modules.local/ppcp-button/src/Endpoint/class-approveorderendpoint.php b/modules.local/ppcp-button/src/Endpoint/class-approveorderendpoint.php
index ce1fd2863..dfa7a9fad 100644
--- a/modules.local/ppcp-button/src/Endpoint/class-approveorderendpoint.php
+++ b/modules.local/ppcp-button/src/Endpoint/class-approveorderendpoint.php
@@ -127,7 +127,7 @@ class ApproveOrderEndpoint implements EndpointInterface {
 						)
 					);
 				}
-				$this->session_handler->replaceOrder( $order );
+				$this->session_handler->replace_order( $order );
 				wp_send_json_success( $order );
 			}
 
@@ -141,7 +141,7 @@ class ApproveOrderEndpoint implements EndpointInterface {
 				);
 			}
 
-			$this->session_handler->replaceOrder( $order );
+			$this->session_handler->replace_order( $order );
 			wp_send_json_success( $order );
 			return true;
 		} catch ( \RuntimeException $error ) {
diff --git a/modules.local/ppcp-button/src/Endpoint/class-createorderendpoint.php b/modules.local/ppcp-button/src/Endpoint/class-createorderendpoint.php
index b882b9ab5..4bcd7ed12 100644
--- a/modules.local/ppcp-button/src/Endpoint/class-createorderendpoint.php
+++ b/modules.local/ppcp-button/src/Endpoint/class-createorderendpoint.php
@@ -145,7 +145,7 @@ class CreateOrderEndpoint implements EndpointInterface {
 			}
 			$bn_code = isset( $data['bn_code'] ) ? (string) $data['bn_code'] : '';
 			if ( $bn_code ) {
-				$this->session_handler->replaceBnCode( $bn_code );
+				$this->session_handler->replace_bn_code( $bn_code );
 				$this->api_endpoint->with_bn_code( $bn_code );
 			}
 			$payee_preferred = $this->settings->has( 'payee_preferred' )
diff --git a/modules.local/ppcp-session/extensions.php b/modules.local/ppcp-session/extensions.php
index 280e6c73c..8c1b048a6 100644
--- a/modules.local/ppcp-session/extensions.php
+++ b/modules.local/ppcp-session/extensions.php
@@ -1,8 +1,12 @@
 <?php
+/**
+ * The extensions of the session module.
+ *
+ * @package Inpsyde\PayPalCommerce\Session
+ */
+
 declare(strict_types=1);
 
 namespace Inpsyde\PayPalCommerce\Session;
 
-return [
-
-];
+return array();
diff --git a/modules.local/ppcp-session/module.php b/modules.local/ppcp-session/module.php
index 2885d071b..b0ddd482f 100644
--- a/modules.local/ppcp-session/module.php
+++ b/modules.local/ppcp-session/module.php
@@ -1,4 +1,10 @@
 <?php
+/**
+ * The session module.
+ *
+ * @package Inpsyde\PayPalCommerce\Session
+ */
+
 declare(strict_types=1);
 
 namespace Inpsyde\PayPalCommerce\Session;
@@ -6,5 +12,5 @@ namespace Inpsyde\PayPalCommerce\Session;
 use Dhii\Modular\Module\ModuleInterface;
 
 return function (): ModuleInterface {
-    return new SessionModule();
+	return new SessionModule();
 };
diff --git a/modules.local/ppcp-session/services.php b/modules.local/ppcp-session/services.php
index bea9b30a6..c8ffe0bc3 100644
--- a/modules.local/ppcp-session/services.php
+++ b/modules.local/ppcp-session/services.php
@@ -1,4 +1,10 @@
 <?php
+/**
+ * The services of the session module.
+ *
+ * @package Inpsyde\PayPalCommerce\Session
+ */
+
 declare(strict_types=1);
 
 namespace Inpsyde\PayPalCommerce\Session;
@@ -7,27 +13,27 @@ use Dhii\Data\Container\ContainerInterface;
 use Inpsyde\PayPalCommerce\Session\Cancellation\CancelController;
 use Inpsyde\PayPalCommerce\Session\Cancellation\CancelView;
 
-return [
-    'session.handler' => function (ContainerInterface $container) : SessionHandler {
+return array(
+	'session.handler'                 => function ( ContainerInterface $container ) : SessionHandler {
 
-        if (is_null(WC()->session)) {
-            return new SessionHandler();
-        }
-        $result = WC()->session->get(SessionHandler::ID);
-        if (is_a($result, SessionHandler::class)) {
-            return $result;
-        }
-        $sessionHandler = new SessionHandler();
-        WC()->session->set(SessionHandler::ID, $sessionHandler);
-        return $sessionHandler;
-    },
-    'session.cancellation.view' => function (ContainerInterface $container) : CancelView {
-        return new CancelView();
-    },
-    'session.cancellation.controller' => function (ContainerInterface $container) : CancelController {
-        return new CancelController(
-            $container->get('session.handler'),
-            $container->get('session.cancellation.view')
-        );
-    },
-];
+		if ( is_null( WC()->session ) ) {
+			return new SessionHandler();
+		}
+		$result = WC()->session->get( SessionHandler::ID );
+		if ( is_a( $result, SessionHandler::class ) ) {
+			return $result;
+		}
+		$session_handler = new SessionHandler();
+		WC()->session->set( SessionHandler::ID, $session_handler );
+		return $session_handler;
+	},
+	'session.cancellation.view'       => function ( ContainerInterface $container ) : CancelView {
+		return new CancelView();
+	},
+	'session.cancellation.controller' => function ( ContainerInterface $container ) : CancelController {
+		return new CancelController(
+			$container->get( 'session.handler' ),
+			$container->get( 'session.cancellation.view' )
+		);
+	},
+);
diff --git a/modules.local/ppcp-session/src/Cancellation/class-cancelcontroller.php b/modules.local/ppcp-session/src/Cancellation/class-cancelcontroller.php
index 89ee3eb79..2d912ddb9 100644
--- a/modules.local/ppcp-session/src/Cancellation/class-cancelcontroller.php
+++ b/modules.local/ppcp-session/src/Cancellation/class-cancelcontroller.php
@@ -1,46 +1,74 @@
 <?php
+/**
+ * Controlls the cancel mechanism to step out of the PayPal order session.
+ *
+ * @package Inpsyde\PayPalCommerce\Session\Cancellation
+ */
+
 declare(strict_types=1);
 
 namespace Inpsyde\PayPalCommerce\Session\Cancellation;
 
 use Inpsyde\PayPalCommerce\Session\SessionHandler;
 
-class CancelController
-{
+/**
+ * Class CancelController
+ */
+class CancelController {
 
-    private $sessionHandler;
-    private $view;
-    public function __construct(
-        SessionHandler $sessionHandler,
-        CancelView $view
-    ) {
+	/**
+	 * The Session handler.
+	 *
+	 * @var SessionHandler
+	 */
+	private $session_handler;
 
-        $this->view = $view;
-        $this->sessionHandler = $sessionHandler;
-    }
+	/**
+	 * The view.
+	 *
+	 * @var CancelView
+	 */
+	private $view;
 
-    public function run()
-    {
-        $paramName = 'ppcp-cancel';
-        $nonce = 'ppcp-cancel-' . get_current_user_id();
-        if (isset($_GET[$paramName]) && // Input var ok.
-            wp_verify_nonce(
-                sanitize_text_field(wp_unslash($_GET[$paramName])), // Input var ok.
-                $nonce
-            )
-        ) { // Input var ok.
-            $this->sessionHandler->destroySessionData();
-        }
-        if (! $this->sessionHandler->order()) {
-            return;
-        }
+	/**
+	 * CancelController constructor.
+	 *
+	 * @param SessionHandler $session_handler The session handler.
+	 * @param CancelView     $view The view object.
+	 */
+	public function __construct(
+		SessionHandler $session_handler,
+		CancelView $view
+	) {
 
-        $url = add_query_arg([$paramName => wp_create_nonce($nonce)], wc_get_checkout_url());
-        add_action(
-            'woocommerce_review_order_after_submit',
-            function () use ($url) {
-                $this->view->renderSessionCancelation($url);
-            }
-        );
-    }
+		$this->view            = $view;
+		$this->session_handler = $session_handler;
+	}
+
+	/**
+	 * Runs the controller.
+	 */
+	public function run() {
+		$param_name = 'ppcp-cancel';
+		$nonce      = 'ppcp-cancel-' . get_current_user_id();
+		if ( isset( $_GET[ $param_name ] ) && // Input var ok.
+			wp_verify_nonce(
+				sanitize_text_field( wp_unslash( $_GET[ $param_name ] ) ), // Input var ok.
+				$nonce
+			)
+		) { // Input var ok.
+			$this->session_handler->destroy_session_data();
+		}
+		if ( ! $this->session_handler->order() ) {
+			return;
+		}
+
+		$url = add_query_arg( array( $param_name => wp_create_nonce( $nonce ) ), wc_get_checkout_url() );
+		add_action(
+			'woocommerce_review_order_after_submit',
+			function () use ( $url ) {
+				$this->view->render_session_cancellation( $url );
+			}
+		);
+	}
 }
diff --git a/modules.local/ppcp-session/src/Cancellation/class-cancelview.php b/modules.local/ppcp-session/src/Cancellation/class-cancelview.php
index 4f4ec6027..d93d95803 100644
--- a/modules.local/ppcp-session/src/Cancellation/class-cancelview.php
+++ b/modules.local/ppcp-session/src/Cancellation/class-cancelview.php
@@ -1,30 +1,42 @@
 <?php
+/**
+ * Renders the cancel view for the order on the checkout.
+ *
+ * @package Inpsyde\PayPalCommerce\Session\Cancellation
+ */
+
 declare(strict_types=1);
 
 namespace Inpsyde\PayPalCommerce\Session\Cancellation;
 
-class CancelView
-{
+/**
+ * Class CancelView
+ */
+class CancelView {
 
-    public function renderSessionCancelation(string $url)
-    {
-        ?>
-        <p id="ppcp-cancel"
-            class="has-text-align-center ppcp-cancel"
-        >
-            <?php
-            printf(
-                    // translators: the placeholders are html tags for a link
-                    esc_html__(
-                            'You are currently paying with PayPal. If you want to cancel
+	/**
+	 * Renders the cancel link.
+	 *
+	 * @param string $url The URL.
+	 */
+	public function render_session_cancellation( string $url ) {
+		?>
+		<p id="ppcp-cancel"
+			class="has-text-align-center ppcp-cancel"
+		>
+			<?php
+			printf(
+					// translators: the placeholders are html tags for a link.
+				esc_html__(
+					'You are currently paying with PayPal. If you want to cancel
                             this process, please click %1$shere%2$s.',
-                            'woocommerce-paypal-commerce-gateway'
-                    ),
-                '<a href="'. esc_url($url) . '">',
-                '</a>'
-            );
-            ?>
-        </p>
-        <?php
-    }
+					'woocommerce-paypal-commerce-gateway'
+				),
+				'<a href="' . esc_url( $url ) . '">',
+				'</a>'
+			);
+			?>
+		</p>
+		<?php
+	}
 }
diff --git a/modules.local/ppcp-session/src/class-sessionhandler.php b/modules.local/ppcp-session/src/class-sessionhandler.php
index 86fa65462..380abbbaf 100644
--- a/modules.local/ppcp-session/src/class-sessionhandler.php
+++ b/modules.local/ppcp-session/src/class-sessionhandler.php
@@ -1,50 +1,97 @@
 <?php
+/**
+ * The Session Handler.
+ *
+ * @package Inpsyde\PayPalCommerce\Session
+ */
+
 declare(strict_types=1);
 
 namespace Inpsyde\PayPalCommerce\Session;
 
 use Inpsyde\PayPalCommerce\ApiClient\Entity\Order;
 
-class SessionHandler
-{
-    const ID = 'ppcp';
+/**
+ * Class SessionHandler
+ */
+class SessionHandler {
 
-    private $order;
-    private $bnCode = '';
-    public function order() : ?Order
-    {
-        return $this->order;
-    }
+	const ID = 'ppcp';
 
-    public function replaceOrder(Order $order) : SessionHandler
-    {
-        $this->order = $order;
-        $this->storeSession();
-        return $this;
-    }
+	/**
+	 * The Order.
+	 *
+	 * @var Order|null
+	 */
+	private $order;
 
-    public function bnCode() : string
-    {
-        return $this->bnCode;
-    }
+	/**
+	 * The BN Code.
+	 *
+	 * @var string
+	 */
+	private $bn_code = '';
 
-    public function replaceBnCode(string $bnCode) : SessionHandler
-    {
-        $this->bnCode = $bnCode;
-        $this->storeSession();
-        return $this;
-    }
+	/**
+	 * Returns the order.
+	 *
+	 * @return Order|null
+	 */
+	public function order() : ?Order {
+		return $this->order;
+	}
 
-    public function destroySessionData() : SessionHandler
-    {
-        $this->order = null;
-        $this->bnCode = '';
-        $this->storeSession();
-        return $this;
-    }
+	/**
+	 * Replaces the current order.
+	 *
+	 * @param Order $order The new order.
+	 *
+	 * @return SessionHandler
+	 */
+	public function replace_order( Order $order ) : SessionHandler {
+		$this->order = $order;
+		$this->store_session();
+		return $this;
+	}
 
-    private function storeSession()
-    {
-        WC()->session->set(self::ID, $this);
-    }
+	/**
+	 * Returns the BN Code.
+	 *
+	 * @return string
+	 */
+	public function bn_code() : string {
+		return $this->bn_code;
+	}
+
+	/**
+	 * Replaces the BN Code.
+	 *
+	 * @param string $bn_code The new BN Code.
+	 *
+	 * @return SessionHandler
+	 */
+	public function replace_bn_code( string $bn_code ) : SessionHandler {
+		$this->bn_code = $bn_code;
+		$this->store_session();
+		return $this;
+	}
+
+	/**
+	 * Destroys the session data.
+	 *
+	 * @return SessionHandler
+	 */
+	public function destroy_session_data() : SessionHandler {
+		$this->order   = null;
+		$this->bn_code = '';
+		$this->store_session();
+		return $this;
+	}
+
+	/**
+	 * Stores the session.
+	 */
+	private function store_session() {
+		WC()->session->set( self::ID, $this );
+	}
 }
diff --git a/modules.local/ppcp-session/src/class-sessionmodule.php b/modules.local/ppcp-session/src/class-sessionmodule.php
index 0f398b39a..d36b30df0 100644
--- a/modules.local/ppcp-session/src/class-sessionmodule.php
+++ b/modules.local/ppcp-session/src/class-sessionmodule.php
@@ -1,4 +1,10 @@
 <?php
+/**
+ * The session module.
+ *
+ * @package Inpsyde\PayPalCommerce\Session
+ */
+
 declare(strict_types=1);
 
 namespace Inpsyde\PayPalCommerce\Session;
@@ -9,28 +15,40 @@ use Inpsyde\PayPalCommerce\Session\Cancellation\CancelController;
 use Interop\Container\ServiceProviderInterface;
 use Psr\Container\ContainerInterface;
 
-class SessionModule implements ModuleInterface
-{
+/**
+ * Class SessionModule
+ */
+class SessionModule implements ModuleInterface {
 
-    public function setup(): ServiceProviderInterface
-    {
-        return new ServiceProvider(
-            require __DIR__.'/../services.php',
-            require __DIR__.'/../extensions.php'
-        );
-    }
+	/**
+	 * Sets up the module.
+	 *
+	 * @return ServiceProviderInterface
+	 */
+	public function setup(): ServiceProviderInterface {
+		return new ServiceProvider(
+			require __DIR__ . '/../services.php',
+			require __DIR__ . '/../extensions.php'
+		);
+	}
 
-    public function run(ContainerInterface $container)
-    {
-        add_action(
-            'woocommerce_init',
-            function () use ($container) {
-                $controller = $container->get('session.cancellation.controller');
-                /**
-                 * @var CancelController $controller
-                 */
-                $controller->run();
-            }
-        );
-    }
+	/**
+	 * Run the module.
+	 *
+	 * @param ContainerInterface $container The container.
+	 */
+	public function run( ContainerInterface $container ) {
+		add_action(
+			'woocommerce_init',
+			function () use ( $container ) {
+				$controller = $container->get( 'session.cancellation.controller' );
+				/**
+				 * The Cancel controller.
+				 *
+				 * @var CancelController $controller
+				 */
+				$controller->run();
+			}
+		);
+	}
 }
diff --git a/modules.local/ppcp-wc-gateway/extensions.php b/modules.local/ppcp-wc-gateway/extensions.php
index d52216bb2..be3b4e051 100644
--- a/modules.local/ppcp-wc-gateway/extensions.php
+++ b/modules.local/ppcp-wc-gateway/extensions.php
@@ -54,7 +54,7 @@ return array(
 		 * @var SessionHandler $session_handler
 		 */
 		$session_handler = $container->get( 'session.handler' );
-		$bn_code         = $session_handler->bnCode();
+		$bn_code         = $session_handler->bn_code();
 
 		/**
 		 * The settings.
diff --git a/modules.local/ppcp-wc-gateway/src/Gateway/class-paypalgateway.php b/modules.local/ppcp-wc-gateway/src/Gateway/class-paypalgateway.php
index 4a98d93e4..719d3b959 100644
--- a/modules.local/ppcp-wc-gateway/src/Gateway/class-paypalgateway.php
+++ b/modules.local/ppcp-wc-gateway/src/Gateway/class-paypalgateway.php
@@ -210,7 +210,7 @@ class PayPalGateway extends \WC_Payment_Gateway {
 				);
 			}
 
-			$this->session_handler->destroySessionData();
+			$this->session_handler->destroy_session_data();
 		}
 		wc_add_notice(
 			$this->order_processor->last_error(),
diff --git a/modules.local/ppcp-wc-gateway/src/Processor/class-orderprocessor.php b/modules.local/ppcp-wc-gateway/src/Processor/class-orderprocessor.php
index 012c470eb..2061b2a73 100644
--- a/modules.local/ppcp-wc-gateway/src/Processor/class-orderprocessor.php
+++ b/modules.local/ppcp-wc-gateway/src/Processor/class-orderprocessor.php
@@ -179,7 +179,7 @@ class OrderProcessor {
 			$wc_order->update_status( 'processing' );
 		}
 		$woocommerce->cart->empty_cart();
-		$this->session_handler->destroySessionData();
+		$this->session_handler->destroy_session_data();
 		$this->last_error = '';
 		return true;
 	}
diff --git a/tests/PHPUnit/WcGateway/Processor/OrderProcessorTest.php b/tests/PHPUnit/WcGateway/Processor/OrderProcessorTest.php
index c1cfcd187..adeda92f7 100644
--- a/tests/PHPUnit/WcGateway/Processor/OrderProcessorTest.php
+++ b/tests/PHPUnit/WcGateway/Processor/OrderProcessorTest.php
@@ -49,7 +49,7 @@ class OrderProcessorTest extends TestCase
             ->expects('order')
             ->andReturn($currentOrder);
         $sessionHandler
-            ->expects('destroySessionData');
+            ->expects('destroy_session_data');
         $cartRepository = Mockery::mock(CartRepository::class);
         $orderEndpoint = Mockery::mock(OrderEndpoint::class);
         $orderEndpoint
@@ -142,7 +142,7 @@ class OrderProcessorTest extends TestCase
             ->expects('order')
             ->andReturn($currentOrder);
         $sessionHandler
-            ->expects('destroySessionData');
+            ->expects('destroy_session_data');
         $cartRepository = Mockery::mock(CartRepository::class);
         $orderEndpoint = Mockery::mock(OrderEndpoint::class);
         $orderEndpoint