ACP2E-94: When product is removed in Multiaddress checkout, the address dropdown value changes to default of all product.

IT for test coverage implemented

Author: rajan-adobe

dev/tests/integration/testsuite/Magento/Quote/Model/QuoteTest.php

@@ -8,6 +8,7 @@
 namespace Magento\Quote\Model;
 
 use Magento\Catalog\Api\ProductRepositoryInterface;
+use Magento\Checkout\Model\Session as CheckoutSession;
 use Magento\Customer\Api\CustomerRepositoryInterface;
 use Magento\Customer\Api\Data\CustomerInterface;
 use Magento\Customer\Api\Data\CustomerInterfaceFactory;
@@ -761,4 +762,46 @@ public function testValidateMinimumAmountWithPriceInclTaxAndDiscount()
         $this->assertEquals(5, $quote->getShippingAddress()->getBaseGrandTotal());
         $this->assertTrue($quote->validateMinimumAmount());
     }
+
+    /**
+     * @magentoConfigFixture current_store multishipping/options/checkout_multiple 1
+     * @magentoAppIsolation enabled
+     * @magentoDbIsolation enabled
+     * @magentoDataFixture Magento/Multishipping/Fixtures/quote_with_split_items.php
+     * @return void
+     */
+    public function testIsMultiShippingModeEnabledAfterQuoteItemRemoved(): void
+    {
+        $quote = $this->getQuoteByReservedOrderId->execute('multishipping_quote_id');
+        /** @var CheckoutSession $session */
+        $session = $this->objectManager->get(CheckoutSession::class);
+        $session->replaceQuote($quote);
+        $items = $quote->getAllItems();
+        $idToDelete = null;
+        foreach($items as $item) {
+            if (!$item->getProduct()->isVirtual() && $item->getQty() == 1) {
+                $idToDelete = $item->getId();
+            }
+        }
+
+        if (!is_null($idToDelete)) {
+            $quoteShippingAddresses = $quote->getAllShippingAddresses();
+            foreach($quoteShippingAddresses as $shippingAddress) {
+                if ($shippingAddress->getItemById($idToDelete)) {
+                    $shippingAddress->removeItem($idToDelete);
+                    $shippingAddress->setCollectShippingRates(true);
+
+                    if (count($shippingAddress->getAllItems()) == 0) {
+                        $shippingAddress->isDeleted(true);
+                    }
+                }
+            }
+            $quote->removeItem($idToDelete);
+            $this->assertEquals(1, $quote->getIsMultiShipping(),
+                "Multi-shipping mode is disabled after quote item removal");
+        } else {
+            $this->assertTrue(!is_null($idToDelete),
+                "No Simple Product item with qty 1 to delete exists");
+        }
+    }
 }