GraphQL-526: Cannot return null for non-nullable field AvailableShippingMethod.method_code when no shipping methods are available

Author: naydav

app/code/Magento/QuoteGraphQl/Model/Resolver/ShippingAddress/AvailableShippingMethods.php

@@ -10,7 +10,6 @@
 use Magento\Framework\Api\ExtensibleDataObjectConverter;
 use Magento\Framework\Exception\LocalizedException;
 use Magento\Framework\GraphQl\Config\Element\Field;
-use Magento\Framework\GraphQl\Exception\GraphQlNoSuchEntityException;
 use Magento\Framework\GraphQl\Query\ResolverInterface;
 use Magento\Framework\GraphQl\Schema\Type\ResolveInfo;
 use Magento\Quote\Api\Data\ShippingMethodInterface;
@@ -66,19 +65,13 @@ public function resolve(Field $field, $context, ResolveInfo $info, array $value
         $shippingRates = $address->getGroupedAllShippingRates();
         foreach ($shippingRates as $carrierRates) {
             foreach ($carrierRates as $rate) {
-                $method = $this->dataObjectConverter->toFlatArray(
+                $methods[] = $this->dataObjectConverter->toFlatArray(
                     $this->shippingMethodConverter->modelToDataObject($rate, $cart->getQuoteCurrencyCode()),
                     [],
                     ShippingMethodInterface::class
                 );
-                if ($method['available'] && $method['error_message'] === "") {
-                    $methods[] = $method;
-                }
             }
         }
-        if (count($methods) === 0) {
-            throw new GraphQlNoSuchEntityException(__(' This shipping method is not available. To use this shipping method, please contact us.'));
-        }
         return $methods;
     }
 }

app/code/Magento/QuoteGraphQl/etc/schema.graphqls

@@ -231,13 +231,14 @@ type SelectedShippingMethod {
 type AvailableShippingMethod {
     carrier_code: String!
     carrier_title: String!
-    method_code: String!
-    method_title: String!
+    method_code: String @doc(description: "Could be null if method is not available")
+    method_title: String @doc(description: "Could be null if method is not available")
     error_message: String
     amount: Float!
-    base_amount: Float!
+    base_amount: Float @doc(description: "Could be null if method is not available")
     price_excl_tax: Float!
     price_incl_tax: Float!
+    available: Boolean!
 }
 
 type AvailablePaymentMethod {