MC-40262: Issue with setShippingMethodsOnCart GraphQL Method - PWA

- Fix logged in customer should be able to checkout if "Allow Guest Checkout" is disabled

Author: bubasuma

app/code/Magento/QuoteGraphQl/Model/Cart/CheckCartCheckoutAllowance.php

@@ -39,7 +39,7 @@ public function __construct(
      */
     public function execute(Quote $quote): void
     {
-        if (false === $quote->getCustomerIsGuest()) {
+        if (!$quote->getCustomerIsGuest()) {
             return;
         }
 

dev/tests/api-functional/testsuite/Magento/GraphQl/Quote/Customer/SetBillingAddressOnCartTest.php

@@ -1759,4 +1759,16 @@ private function getPlaceOrderQuery(string $maskedQuoteId): string
 }
 QUERY;
     }
+
+    /**
+     * @magentoApiDataFixture Magento/Customer/_files/customer.php
+     * @magentoApiDataFixture Magento/GraphQl/Catalog/_files/simple_product.php
+     * @magentoApiDataFixture Magento/GraphQl/Quote/_files/customer/create_empty_cart.php
+     * @magentoApiDataFixture Magento/GraphQl/Quote/_files/add_simple_product.php
+     * @magentoConfigFixture default_store checkout/options/guest_checkout 0
+     */
+    public function testSetBillingAddressAndPlaceOrderWithGuestCheckoutDisabled()
+    {
+        $this->testSetBillingAddressAndPlaceOrder();
+    }
 }

dev/tests/api-functional/testsuite/Magento/GraphQl/Quote/Customer/SetShippingAddressOnCartTest.php

@@ -1950,4 +1950,17 @@ private function getPlaceOrderQuery(string $maskedQuoteId): string
 }
 QUERY;
     }
+
+    /**
+     * @magentoApiDataFixture Magento/Customer/_files/customer.php
+     * @magentoApiDataFixture Magento/GraphQl/Catalog/_files/simple_product.php
+     * @magentoApiDataFixture Magento/GraphQl/Quote/_files/customer/create_empty_cart.php
+     * @magentoApiDataFixture Magento/GraphQl/Quote/_files/add_simple_product.php
+     * @magentoApiDataFixture Magento/GraphQl/Quote/_files/set_new_billing_address.php
+     * @magentoConfigFixture default_store checkout/options/guest_checkout 0
+     */
+    public function testSetNewShippingAddressAndPlaceOrderWithGuestCheckoutDisabled()
+    {
+        $this->testSetNewShippingAddressAndPlaceOrder();
+    }
 }