Merge branch 'lazy-types' into v0.10

# Conflicts:
#	src/Executor/Executor.php

Author: vladar

benchmarks/HugeSchemaBench.php

@@ -22,7 +22,7 @@ class HugeSchemaBench
     private $schemaBuilder;
 
     /**
-     * @var array
+     * @var Schema\Descriptor
      */
     private $descriptor;
 
@@ -54,7 +54,9 @@ public function setUp()
     public function benchSchema()
     {
         $this->schemaBuilder
-            ->buildSchema();
+            ->buildSchema()
+            ->getTypeMap()
+        ;
     }
 
     public function benchSchemaLazy()
@@ -75,16 +77,13 @@ public function benchSmallQueryLazy()
 
     private function createLazySchema()
     {
-        $strategy = new LazyResolution(
-            $this->descriptor,
-            function($name) {
-                return $this->schemaBuilder->loadType($name);
-            }
+        return new Schema(
+            Schema\Config::create()
+                ->setQuery($this->schemaBuilder->buildQueryType())
+                // ->setDescriptor($this->descriptor)
+                ->setTypeLoader(function($name) {
+                    return $this->schemaBuilder->loadType($name);
+                })
         );
-
-        return new Schema([
-            'query' => $this->schemaBuilder->buildQueryType(),
-            'typeResolution' => $strategy,
-        ]);
     }
 }

src/Executor/Executor.php

@@ -5,6 +5,7 @@
 use GraphQL\Error\InvariantViolation;
 use GraphQL\Executor\Promise\Adapter\SyncPromiseAdapter;
 use GraphQL\Executor\Promise\Promise;
+use GraphQL\GraphQL;
 use GraphQL\Language\AST\DocumentNode;
 use GraphQL\Language\AST\FieldNode;
 use GraphQL\Language\AST\FragmentDefinitionNode;
@@ -18,6 +19,7 @@
 use GraphQL\Type\Definition\AbstractType;
 use GraphQL\Type\Definition\Directive;
 use GraphQL\Type\Definition\FieldDefinition;
+use GraphQL\Type\Definition\InterfaceType;
 use GraphQL\Type\Definition\LeafType;
 use GraphQL\Type\Definition\ListOfType;
 use GraphQL\Type\Definition\NonNull;
@@ -1021,6 +1023,16 @@ private function completeAbstractValue(AbstractType $returnType, $fieldNodes, Re
         $runtimeType = $returnType->resolveType($result, $exeContext->contextValue, $info);
 
         if (null === $runtimeType) {
+            if ($returnType instanceof InterfaceType && !$exeContext->schema->getConfig()->descriptor &&
+                !GraphQL::isIgnoredError(GraphQL::WARNING_ON_IMPLEMENTATION_RESOLUTION)) {
+                trigger_error(
+                    "GraphQL Interface Type `{$returnType->name}` returned `null` from it`s `resolveType` function ".
+                    'for value: ' . Utils::printSafe($result) . '. Switching to slow resolution method using `isTypeOf` ' .
+                    'of all possible implementations. It degrades query performance significantly. '.
+                    ' Make sure your `resolveType` always returns valid implementation or throws.',
+                    E_USER_WARNING
+                );
+            }
             $runtimeType = self::defaultTypeResolver($result, $exeContext->contextValue, $info, $returnType);
         }
 

src/GraphQL.php

@@ -16,6 +16,20 @@
 
 class GraphQL
 {
+    const WARNING_ON_IMPLEMENTATION_RESOLUTION = 1;
+
+    private static $ignoredErrors = [];
+
+    public static function setIgnoreError($errorCode, $set = true)
+    {
+        self::$ignoredErrors[$errorCode] = $set ? true : null;
+    }
+
+    public static function isIgnoredError($errorCode)
+    {
+        return isset(self::$ignoredErrors[$errorCode]);
+    }
+
     /**
      * This is the primary entry point function for fulfilling GraphQL operations
      * by parsing, validating, and executing a GraphQL document along side a