src/Utils/SchemaExtender.php
protected static function getMergedDirectives(Schema $schema, array $directiveDefinitions) : array
    {
        $existingDirectives = array_map(static function (Directive $directive) {
            return static::extendDirective($directive);
        }, $schema->getDirectives());

        Utils::invariant(count($existingDirectives) > 0, 'schema must have default directives');

        return array_merge(
            $existingDirectives,
            array_map(static function (DirectiveDefinitionNode $directive) {
                return static::$astBuilder->buildDirective($directive);
            }, $directiveDefinitions)
        );
    }
protected static function getMergedDirectives(Schema $schema, array $directiveDefinitions) : array
    {
        $existingDirectives = array_map(static function (Directive $directive) {
            return static::extendDirective($directive);
        }, $schema->getDirectives());

        Utils::invariant(count($existingDirectives) > 0, 'schema must have default directives');

        return array_merge(
            $existingDirectives,
            array_map(static function (DirectiveDefinitionNode $directive) {
                return static::$astBuilder->buildDirective($directive);
            }, $directiveDefinitions)
        );
    }
@param DirectiveDefinitionNode[] $directiveDefinitions

@return Directive[]