requested changes

Author: engcom-Charlie

app/code/Magento/Checkout/Model/ShippingInformationManagement.php

@@ -30,7 +30,7 @@
 use Psr\Log\LoggerInterface as Logger;
 
 /**
- * @inheritdoc
+ * Class checkout shipping information management
  *
  * @SuppressWarnings(PHPMD.CouplingBetweenObjects)
  */
@@ -224,11 +224,11 @@ public function saveAddressInformation(
     /**
      * Validate shipping address
      *
-     * @param AddressInterface $address
+     * @param AddressInterface|null $address
      * @return void
      * @throws StateException
      */
-    private function validateAddress(AddressInterface $address): void
+    private function validateAddress(?AddressInterface $address): void
     {
         if (!$address || !$address->getCountryId()) {
             throw new StateException(__('The shipping address is missing. Set the address and try again.'));
@@ -244,7 +244,7 @@ private function validateAddress(AddressInterface $address): void
      */
     protected function validateQuote(Quote $quote): void
     {
-        if (!$quote->getItemsCount()) {
+        if (0 === $quote->getItemsCount()) {
             throw new InputException(
                 __('The shipping method can\'t be set for an empty cart. Add an item to cart and try again.')
             );

app/code/Magento/Checkout/Test/Unit/Model/ShippingInformationManagementTest.php

@@ -43,36 +43,26 @@ class ShippingInformationManagementTest extends TestCase
 {
     /**
      * Stub cart id
-     *
-     * @var int
      */
     private const STUB_CART_ID = 100;
 
     /**
      * Stub items count
-     *
-     * @var int
      */
     private const STUB_ITEMS_COUNT = 99;
 
     /**
      * Stub carrier code
-     *
-     * @var string
      */
     private const STUB_CARRIER_CODE = 'carrier_code';
 
     /**
      * Stub shipping method
-     *
-     * @var string
      */
     private const STUB_SHIPPING_METHOD = 'shipping_method';
 
     /**
      * Stub error message
-     *
-     * @var string
      */
     private const STUB_ERROR_MESSAGE = 'error message';