GraphQL\Utils\TypeInfo::doTypesOverlap PHP Метод

    static function doTypesOverlap(Schema $schema, CompositeType $typeA, CompositeType $typeB)
    {
        // Equivalent types overlap
        if ($typeA === $typeB) {
            return true;
        }
        if ($typeA instanceof AbstractType) {
            if ($typeB instanceof AbstractType) {
                // If both types are abstract, then determine if there is any intersection
                // between possible concrete types of each.
                foreach ($schema->getPossibleTypes($typeA) as $type) {
                    if ($schema->isPossibleType($typeB, $type)) {
                        return true;
                    }
                }
                return false;
            }
            /** @var $typeB ObjectType */
            // Determine if the latter type is a possible concrete type of the former.
            return $schema->isPossibleType($typeA, $typeB);
        }
        if ($typeB instanceof AbstractType) {
            /** @var $typeA ObjectType */
            // Determine if the former type is a possible concrete type of the latter.
            return $schema->isPossibleType($typeB, $typeA);
        }
        // Otherwise the types do not overlap.
        return false;
    }

 public function __invoke(ValidationContext $context)
 {
     return [NodeKind::INLINE_FRAGMENT => function (InlineFragmentNode $node) use($context) {
         $fragType = $context->getType();
         $parentType = $context->getParentType();
         if ($fragType && $parentType && !TypeInfo::doTypesOverlap($context->getSchema(), $fragType, $parentType)) {
             $context->reportError(new Error(self::typeIncompatibleAnonSpreadMessage($parentType, $fragType), [$node]));
         }
     }, NodeKind::FRAGMENT_SPREAD => function (FragmentSpreadNode $node) use($context) {
         $fragName = $node->name->value;
         $fragType = $this->getFragmentType($context, $fragName);
         $parentType = $context->getParentType();
         if ($fragType && $parentType && !TypeInfo::doTypesOverlap($context->getSchema(), $fragType, $parentType)) {
             $context->reportError(new Error(self::typeIncompatibleSpreadMessage($fragName, $parentType, $fragType), [$node]));
         }
     }];
 }