[Php81] Skip NullToStrictStringFuncCallArgRector for magic __get() property access

[TomasVotruba]

Fixes rectorphp/rector#9762

Problem

NullToStrictStringFuncCallArgRector incorrectly wraps a magic property access in a (string) cast even when the value is already guarded by a truthy if check:

class Entity
{
    protected array $_fields = [];

    public function __get(string $field)
    {
        $value = null;
        if (isset($this->_fields[$field])) {
            $value = &$this->_fields[$field];
        }
        return $value;
    }
}

$entity = new Entity();
if ($entity->someProp) {
    // incorrectly became: preg_replace('/\r\n|\n|\r/', '', (string) $entity->someProp);
    preg_replace('/\r\n|\n|\r/', '', $entity->someProp);
}

Root Cause

When __get() has no return type hint, PHPStan resolves any magic property access to ErrorType (shown as *ERROR* in dumpType). Since ErrorType extends MixedType, the existing shouldSkipType() check treats it as a plain MixedType and does not skip. The isAnErrorType() guard also misses it because it inspects the native type (plain MixedType) and its parent-scope fallback only fires inside closures/functions — at the top level getParentScope() returns null.

Fix

In shouldSkipValue(), check upfront whether the argument is a PropertyFetch on a class that declares __get(). If so, the type is unresolvable via static analysis and the cast would be wrong.

private function isPropertyFetchOnClassWithMagicGet(Expr $expr): bool
{
    if (! $expr instanceof PropertyFetch) {
        return false;
    }

    $varType = $this->nodeTypeResolver->getType($expr->var);
    if (! $varType instanceof ObjectType) {
        return false;
    }

    if (! $this->reflectionProvider->hasClass($varType->getClassName())) {
        return false;
    }

    return $this->reflectionProvider->getClass($varType->getClassName())->hasMethod('__get');
}

hasMethod('__get') resolves through the full inheritance chain, so it also covers classes that inherit __get() from a parent (e.g. CakePHP's EntityTrait).

Test

Added skip_magic_get_property_in_if_truthy_check.php.inc fixture reproducing the exact scenario from the issue.

[TomasVotruba]

Looks good 🙏