Testing private methods properties

tests\bootstrap\helpers.php

<?php

if (!function_exists('private_access')) {
    function private_access(object $object)
    {
        return new PrivateAccess($object);
    }
}

tests\Support\PrivateAccess.php

<?php

namespace Tests\Support;

use ReflectionClass;
use ReflectionException;
use ReflectionObject;

class PrivateAccess
{
    public function __construct(
        private object $object,
    ) {
    }

    /**
     * @throws ReflectionException
     */
    public function __call(string $methodName, array $arguments): mixed
    {
        $class = new ReflectionClass($this->object);
        $method = $class->getMethod($methodName);
        $method->setAccessible(true);

        return $method->invokeArgs($this->object, $arguments);
    }

    /**
     * @throws ReflectionException
     */
    public function __get(string $name): mixed
    {
        $class = new ReflectionObject($this->object);
        $property = $class->getProperty($name);
        $property->setAccessible(true);

        return $property->getValue($this->object);
    }

    /**
     * @throws ReflectionException
     */
    public function __set(string $name, mixed $value): void
    {
        $reflection = new ReflectionClass($this->object);
        $reflectionProperty = $reflection->getProperty($name);
        $reflectionProperty->setAccessible(true);
        $reflectionProperty->setValue($this->object, $value);
    }
}