Improve error handling for cycles in default values

Author: peldax

src/Typesystem/InputType.php

@@ -9,6 +9,7 @@
 use Graphpinator\Typesystem\Contract\NamedTypeVisitor;
 use Graphpinator\Typesystem\DirectiveUsage\DirectiveUsage;
 use Graphpinator\Typesystem\DirectiveUsage\DirectiveUsageSet;
+use Graphpinator\Typesystem\Exception\ArgumentDefaultValueCycleDetected;
 use Graphpinator\Typesystem\Location\InputObjectLocation;
 use Graphpinator\Typesystem\Spec\OneOfDirective;
 use Graphpinator\Typesystem\Utils\THasDirectives;
@@ -20,6 +21,7 @@ abstract class InputType extends NamedType
     protected const DATA_CLASS = \stdClass::class;
 
     protected ?ArgumentSet $arguments = null;
+    private bool $isLoadingArguments = false;
 
     public function __construct()
     {
@@ -29,6 +31,11 @@ public function __construct()
     final public function getArguments() : ArgumentSet
     {
         if (!$this->arguments instanceof ArgumentSet) {
+            if ($this->isLoadingArguments) {
+                throw new ArgumentDefaultValueCycleDetected($this->getName());
+            }
+
+            $this->isLoadingArguments = true;
             $this->arguments = $this->getFieldDefinition();
             $this->afterGetFieldDefinition();
         }

tests/Unit/Typesystem/EnumTypeTest.php

@@ -6,7 +6,6 @@
 
 use Graphpinator\Common\Path;
 use Graphpinator\Typesystem\EnumType;
-use Graphpinator\Typesystem\Spec\DeprecatedDirective;
 use Graphpinator\Value\Exception\InvalidValue;
 use Graphpinator\Value\Visitor\ConvertRawValueVisitor;
 use PHPUnit\Framework\Attributes\DataProvider;

tests/Unit/Typesystem/Visitor/ValidateIntegrityVisitorTest.php

@@ -12,6 +12,7 @@
 use Graphpinator\Typesystem\EnumItem\EnumItem;
 use Graphpinator\Typesystem\EnumItem\EnumItemSet;
 use Graphpinator\Typesystem\EnumType;
+use Graphpinator\Typesystem\Exception\ArgumentDefaultValueCycleDetected;
 use Graphpinator\Typesystem\Exception\ArgumentInvalidTypeUsage;
 use Graphpinator\Typesystem\Exception\DirectiveIncorrectType;
 use Graphpinator\Typesystem\Exception\DuplicateNonRepeatableDirective;
@@ -1405,4 +1406,47 @@ protected function getFieldDefinition() : ArgumentSet
         $this->expectException(NameMustNotStartWithDoubleUnderscore::class);
         $directive->accept(new ValidateIntegrityVisitor());
     }
+
+    public function testArgumentDefaultValueCycleDetected() : void
+    {
+        $inputA = new class extends InputType {
+            protected const NAME = 'InputA';
+
+            public InputType|null $inputB = null;
+
+            #[\Override]
+            protected function getFieldDefinition() : ArgumentSet
+            {
+                return new ArgumentSet([
+                    Argument::create('field', $this->inputB)
+                        ->setDefaultValue(new \stdClass()),
+                ]);
+            }
+        };
+
+        $inputB = new class ($inputA) extends InputType {
+            protected const NAME = 'InputB';
+
+            public function __construct(
+                private InputType $inputA,
+            )
+            {
+                parent::__construct();
+            }
+
+            #[\Override]
+            protected function getFieldDefinition() : ArgumentSet
+            {
+                return new ArgumentSet([
+                    Argument::create('field', $this->inputA)
+                        ->setDefaultValue(new \stdClass()),
+                ]);
+            }
+        };
+
+        $inputA->inputB = $inputB;
+
+        $this->expectException(ArgumentDefaultValueCycleDetected::class);
+        $inputA->accept(new ValidateIntegrityVisitor());
+    }
 }