fix: disable autoloading in typeIsValid to prevent fatal errors during generation

class_exists() in typeIsValid() triggers the autoloader, which can cause
fatal errors during code generation when a freshly-generated class extends
a parent class that hasn't been generated yet. The generation order of
structs is non-deterministic, so this produces intermittent failures.

Passing false as the second argument to class_exists() disables autoloading.
The subsequent stringIsValid() check still validates the type string format,
so there is no loss of validation coverage.

Author: aldenw

src/Element/TypeHintedElementTrait.php

@@ -34,7 +34,7 @@ public static function typeIsValid($type): bool
         return
             is_null($type)
             || $type instanceof PhpClass
-            || (is_string($type) && class_exists($type))
+            || (is_string($type) && class_exists($type, false))
             || in_array($type, TypeHintedElementInterface::TYPES, true)
             || static::stringIsValid($type, true, true);
     }

tests/Element/PhpFunctionParameterTest.php

@@ -46,6 +46,11 @@ public function testTypeIsValidAccentuated()
         $this->assertTrue(PhpFunctionParameter::typeIsValid('Partagé'));
     }
 
+    public function testTypeIsValidWithUnloadedFullyQualifiedClassName()
+    {
+        $this->assertTrue(PhpFunctionParameter::typeIsValid('\\Some\\Namespace\\NonExistentClass'));
+    }
+
     public function testFloatValueForDeclaration()
     {
         $initialSerializePrecision = ini_get('serialize_precision');