ACP2E-2107: Cart GraphQL throwing internal server error for out of stock product

Author: dhorytskyi

app/code/Magento/QuoteGraphQl/Model/Resolver/CartItemErrors.php

@@ -70,7 +70,7 @@ private function getItemErrors(Item $cartItem): ?array
         $errors = [];
         foreach ($cartItem->getErrorInfos() as $error) {
             $errorType = $error['code'] ?? self::ERROR_UNDEFINED;
-            $message = $error['message'] ?? $cartItem->getMessage();
+            $message = (string) ($error['message'] ?? $cartItem->getMessage());
             $errorEnumCode = $this->enumLookup->getEnumValueFromField(
                 'CartItemErrorType',
                 (string)$errorType

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

@@ -123,6 +123,10 @@ public function testConfigurableProductInCartAfterGoesOutOfStock()
                     value
                 }
             }
+            errors {
+                code
+                message
+            }
         }
     }
 }
@@ -149,5 +153,6 @@ public function testConfigurableProductInCartAfterGoesOutOfStock()
             $response['cart']['items'][0]['product']['price_range']['maximum_price']['final_price']['value'],
             'Assert that maximum price equals to 0'
         );
+        $this->assertEquals('ITEM_QTY', $response['cart']['items'][0]['errors'][0]['code']);
     }
 }