BUG#AC-8623: Address Error Handling functionality, lost due to Backward Compatibility Issue in Webonyx GraphQL Library

Author: glo80326

dev/tests/api-functional/testsuite/Magento/GraphQl/Quote/Guest/CartTotalsTest.php

@@ -8,6 +8,7 @@
 namespace Magento\GraphQl\Quote\Guest;
 
 use Magento\Catalog\Test\Fixture\Product as ProductFixture;
+use Magento\Framework\GraphQl\Exception\GraphQlNoSuchEntityException;
 use Magento\GraphQl\Quote\GetMaskedQuoteIdByReservedOrderId;
 use Magento\Quote\Model\QuoteIdToMaskedQuoteIdInterface;
 use Magento\Quote\Test\Fixture\AddProductToCart as AddProductToCartFixture;
@@ -315,6 +316,25 @@ public function testGetSelectedShippingMethodFromCustomerCart()
         $this->graphQlQuery($query);
     }
 
+    public function testGetCartTotalsWithNonExistingCartId(): void
+    {
+        $maskedQuoteId = 'NonExistingQuoteId';
+        $query = $this->getQuery($maskedQuoteId);
+        try {
+            $this->graphQlQuery($query);
+            $this->fail('Expected exception was not raised');
+        } catch (\Exception $exception) {
+            $response = $exception->getResponseData();
+            $this->assertArrayHasKey('errors', $response);
+            $actualError = reset($response['errors']);
+            $this->assertEquals("Could not find a cart with ID \"$maskedQuoteId\"", $actualError['message']);
+            $this->assertEquals(
+                GraphQlNoSuchEntityException::EXCEPTION_CATEGORY,
+                $actualError['extensions']['category']
+            );
+        }
+    }
+
     /**
      * Generates GraphQl query for retrieving cart totals
      *

lib/internal/Magento/Framework/GraphQl/Exception/GraphQlNoSuchEntityException.php

@@ -19,7 +19,7 @@
  */
 class GraphQlNoSuchEntityException extends NoSuchEntityException implements ClientAware, ProvidesExtensions
 {
-    const EXCEPTION_CATEGORY = 'graphql-no-such-entity';
+    public const EXCEPTION_CATEGORY = 'graphql-no-such-entity';
 
     /**
      * @var boolean