Avoid infinite loop when using recursive types and interfaces (#16)

src/Type/Definition/ListOfType.php

@@ -34,10 +34,12 @@ class ListOfType extends Type implements WrappingType, OutputType, InputType
     }
 
     /**
-     * @return Type
+     * @param bool $recurse
+     * @return mixed
      */
-    public function getWrappedType()
+    public function getWrappedType($recurse = false)
     {
-        return Type::resolve($this->ofType);
+        $type = Type::resolve($this->ofType);
+        return ($recurse && $type instanceof WrappingType) ? $type->getWrappedType($recurse) : $type;
     }
 }

src/Type/Definition/NonNull.php

@@ -29,9 +29,11 @@ class NonNull extends Type implements WrappingType, OutputType, InputType
     }
 
     /**
-     * @return Type|callable
+     * @param bool $recurse
+     * @return Type
+     * @throws \Exception
      */
-    public function getWrappedType()
+    public function getWrappedType($recurse = false)
     {
         $type = Type::resolve($this->ofType);
 
@@ -40,7 +42,7 @@ class NonNull extends Type implements WrappingType, OutputType, InputType
             'Cannot nest NonNull inside NonNull'
         );
 
-        return $type;
+        return ($recurse && $type instanceof WrappingType) ? $type->getWrappedType($recurse) : $type;
     }
 
     /**

src/Type/Definition/ObjectType.php

@@ -64,8 +64,6 @@ class ObjectType extends Type implements OutputType, CompositeType
      */
     private $_config;
 
-    private $_initialized = false;
-
     /**
      * @var callable
      */
@@ -75,36 +73,9 @@ class ObjectType extends Type implements OutputType, CompositeType
     {
         Utils::invariant(!empty($config['name']), 'Every type is expected to have name');
 
-        $this->name = $config['name'];
-        $this->description = isset($config['description']) ? $config['description'] : null;
-        $this->resolveFieldFn = isset($config['resolveField']) ? $config['resolveField'] : null;
-        $this->_config = $config;
-
-        if (isset($config['interfaces'])) {
-            InterfaceType::addImplementationToInterfaces($this);
-        }
-    }
-
-    /**
-     * Late instance initialization
-     */
-    private function initialize()
-    {
-        if ($this->_initialized) {
-            return ;
-        }
-        $config = $this->_config;
-
-        if (isset($config['fields']) && is_callable($config['fields'])) {
-            $config['fields'] = call_user_func($config['fields']);
-        }
-        if (isset($config['interfaces']) && is_callable($config['interfaces'])) {
-            $config['interfaces'] = call_user_func($config['interfaces']);
-        }
-
         // Note: this validation is disabled by default, because it is resource-consuming
         // TODO: add bin/validate script to check if schema is valid during development
-        Config::validate($this->_config, [
+        Config::validate($config, [
             'name' => Config::STRING | Config::REQUIRED,
             'fields' => Config::arrayOf(
                 FieldDefinition::getDefinition(),
@@ -118,10 +89,15 @@ class ObjectType extends Type implements OutputType, CompositeType
             'resolveField' => Config::CALLBACK
         ]);
 
-        $this->_fields = FieldDefinition::createMap($config['fields']);
+        $this->name = $config['name'];
-        $this->_interfaces = isset($config['interfaces']) ? $config['interfaces'] : [];
+        $this->description = isset($config['description']) ? $config['description'] : null;
+        $this->resolveFieldFn = isset($config['resolveField']) ? $config['resolveField'] : null;
         $this->_isTypeOf = isset($config['isTypeOf']) ? $config['isTypeOf'] : null;
-        $this->_initialized = true;
+        $this->_config = $config;
+
+        if (isset($config['interfaces'])) {
+            InterfaceType::addImplementationToInterfaces($this);
+        }
     }
 
     /**
@@ -129,8 +105,10 @@ class ObjectType extends Type implements OutputType, CompositeType
      */
     public function getFields()
     {
-        if (false === $this->_initialized) {
+        if (null === $this->_fields) {
-            $this->initialize();
+            $fields = isset($this->_config['fields']) ? $this->_config['fields'] : [];
+            $fields = is_callable($fields) ? call_user_func($fields) : $fields;
+            $this->_fields = FieldDefinition::createMap($fields);
         }
         return $this->_fields;
     }
@@ -142,8 +120,8 @@ class ObjectType extends Type implements OutputType, CompositeType
      */
     public function getField($name)
     {
-        if (false === $this->_initialized) {
+        if (null === $this->_fields) {
-            $this->initialize();
+            $this->getFields();
         }
         Utils::invariant(isset($this->_fields[$name]), "Field '%s' is not defined for type '%s'", $name, $this->name);
         return $this->_fields[$name];
@@ -154,8 +132,10 @@ class ObjectType extends Type implements OutputType, CompositeType
      */
     public function getInterfaces()
     {
-        if (false === $this->_initialized) {
+        if (null === $this->_interfaces) {
-            $this->initialize();
+            $interfaces = isset($this->_config['interfaces']) ? $this->_config['interfaces'] : [];
+            $interfaces = is_callable($interfaces) ? call_user_func($interfaces) : $interfaces;
+            $this->_interfaces = $interfaces;
         }
         return $this->_interfaces;
     }

src/Type/Definition/WrappingType.php

@@ -8,5 +8,5 @@ interface WrappingType
 NonNullType
 ListOfType
  */
-    public function getWrappedType();
+    public function getWrappedType($recurse = false);
 }

tests/Type/DefinitionTest.php

@@ -342,4 +342,66 @@ class DefinitionTest extends \PHPUnit_Framework_TestCase
         }
         Config::disableValidation();
     }
+
+    public function testAllowsRecursiveDefinitions()
+    {
+        // See https://github.com/webonyx/graphql-php/issues/16
+        $node = new InterfaceType([
+            'name' => 'Node',
+            'fields' => [
+                'id' => ['type' => Type::nonNull(Type::id())]
+            ]
+        ]);
+
+        $blog = null;
+        $called = false;
+
+        $user = new ObjectType([
+            'name' => 'User',
+            'fields' => function() use (&$blog, &$called) {
+                $this->assertNotNull($blog, 'Blog type is expected to be defined at this point, but it is null');
+                $called = true;
+
+                return [
+                    'id' => ['type' => Type::nonNull(Type::id())],
+                    'blogs' => ['type' => Type::nonNull(Type::listOf(Type::nonNull($blog)))]
+                ];
+            },
+            'interfaces' => function() use ($node) {
+                return [$node];
+            }
+        ]);
+
+        $blog = new ObjectType([
+            'name' => 'Blog',
+            'fields' => function() use ($user) {
+                return [
+                    'id' => ['type' => Type::nonNull(Type::id())],
+                    'owner' => ['type' => Type::nonNull($user)]
+                ];
+            },
+            'interfaces' => function() use ($node) {
+                return [$node];
+            }
+        ]);
+
+        $schema = new Schema(new ObjectType([
+            'name' => 'Query',
+            'fields' => [
+                'node' => ['type' => $node]
+            ]
+        ]));
+
+        $this->assertTrue($called);
+
+        $this->assertEquals([$node], $blog->getInterfaces());
+        $this->assertEquals([$node], $user->getInterfaces());
+
+        $this->assertNotNull($user->getField('blogs'));
+        $this->assertSame($blog, $user->getField('blogs')->getType()->getWrappedType(true));
+
+        $this->assertNotNull($blog->getField('owner'));
+        $this->assertSame($user, $blog->getField('owner')->getType()->getWrappedType(true));
+
+    }
 }