ClosureValidationRule::$callback is protected, but public in Laravel #729

Before submitting

• I have read the contribution guide in full and this report meets its requirements.
• I have checked existing issues, documented differences, and deferred work; this is not already tracked or intentionally omitted.
• I have verified that the functionality exists in the upstream version or commit linked below.
• I have run the example below and verified that the behavior is missing from the stated Hypervel version.

Hypervel package and version

hypervel/components 0.4.x-dev, commit 88352d3 (Hypervel\Validation\ClosureValidationRule)

Upstream references

• Repository: https://github.com/laravel/framework
• Implementation: https://github.com/laravel/framework/blob/18bf64aee02dda4efe172c0e3e940be94847b7db/src/Illuminate/Validation/ClosureValidationRule.php#L13-L18
• Introduced in v5.5.0 (bd352a0d2ca93775fce8ef02365b03fc4fb8cbb0) as a public property, and public ever since: https://github.com/laravel/framework/blob/v5.5.0/src/Illuminate/Validation/ClosureValidationRule.php#L14
• Documentation: https://laravel.com/docs/12.x/validation#using-closures

Upstream comparison

Compared against laravel/framework branch 12.x at 18bf64aee02dda4efe172c0e3e940be94847b7db.

Laravel: https://github.com/laravel/framework/blob/18bf64aee02dda4efe172c0e3e940be94847b7db/src/Illuminate/Validation/ClosureValidationRule.php#L13-L18 declares public $callback;.

Hypervel:

Missing behavior

In Laravel, the closure a ClosureValidationRule wraps is readable through its public $callback property. Code that receives the rule, such as the ClosureValidationRule that ValidationRuleParser builds from a closure in a rules array, can read the closure to describe the rule: its docblock, its parameters, or a reflection of it.

In Hypervel the property is protected, so reading $rule->callback throws an Error. The only way to reach the closure is reflection on a non-public member, which breaks without notice if the property is renamed.

The other public properties of Laravel's class ($failed and $messages) are still public in Hypervel, and only $callback changed visibility. I could not find it among the documented differences in src/docs/ or in docs/todo.md.

Expected fix, matching Laravel: public Closure $callback in the constructor.

Minimal example and reproduction steps

Environment: PHP 8.4.27 (CLI, Swoole), hypervel/components 0.4.x-dev at 88352d3.

From the root of any project with hypervel/components installed:

php -r 'require "vendor/autoload.php";
$rule = new Hypervel\Validation\ClosureValidationRule(function (string $attribute, mixed $value, Closure $fail): void {});
var_dump($rule->callback);'

Expected (as in Laravel): object(Closure)#… (…), the closure passed to the constructor.

Actual:

Error: Cannot access protected property Hypervel\Validation\ClosureValidationRule::$callback