Initial Drupal 11 with DDEV setup

vendor/symfony/validator/Constraints/YamlValidator.php

@@ -0,0 +1,63 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\Validator\Constraints;
+
+use Symfony\Component\Validator\Constraint;
+use Symfony\Component\Validator\ConstraintValidator;
+use Symfony\Component\Validator\Exception\UnexpectedTypeException;
+use Symfony\Component\Validator\Exception\UnexpectedValueException;
+use Symfony\Component\Yaml\Exception\ParseException;
+use Symfony\Component\Yaml\Parser;
+
+/**
+ * @author Kev <https://github.com/symfonyaml>
+ */
+class YamlValidator extends ConstraintValidator
+{
+    public function validate(mixed $value, Constraint $constraint): void
+    {
+        if (!$constraint instanceof Yaml) {
+            throw new UnexpectedTypeException($constraint, Yaml::class);
+        }
+
+        if (null === $value || '' === $value) {
+            return;
+        }
+
+        if (!\is_scalar($value) && !$value instanceof \Stringable) {
+            throw new UnexpectedValueException($value, 'string');
+        }
+
+        $value = (string) $value;
+
+        /** @see \Symfony\Component\Yaml\Command\LintCommand::validate() */
+        $prevErrorHandler = set_error_handler(function ($level, $message, $file, $line) use (&$prevErrorHandler) {
+            if (\E_USER_DEPRECATED === $level) {
+                throw new ParseException($message, $this->getParser()->getRealCurrentLineNb() + 1);
+            }
+
+            return $prevErrorHandler ? $prevErrorHandler($level, $message, $file, $line) : false;
+        });
+
+        try {
+            (new Parser())->parse($value, $constraint->flags);
+        } catch (ParseException $e) {
+            $this->context->buildViolation($constraint->message)
+                ->setParameter('{{ error }}', $e->getMessage())
+                ->setParameter('{{ line }}', $e->getParsedLine())
+                ->setCode(Yaml::INVALID_YAML_ERROR)
+                ->addViolation();
+        } finally {
+            restore_error_handler();
+        }
+    }
+}