Return type of yii\web\SessionIterator::current() should either be compatible with Iterator::current()

[dicrtarasov]

yii\base\ErrorException: During inheritance of Iterator: Uncaught yii\base\ErrorException: Return type of yii\web\SessionIterator::current() should either be compatible with Iterator::current(): mixed, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice in /home/eurotools/public_html/vendor/yiisoft/yii2/web/SessionIterator.php:60

Stack trace:
#0 /home/eurotools/public_html/vendor/yiisoft/yii2/web/SessionIterator.php(16): yii\base\ErrorHandler->handleError()
#1 /home/eurotools/public_html/vendor/yiisoft/yii2/BaseYii.php(293): include('...')
#2 /home/eurotools/public_html/vendor/yiisoft/yii2/web/Session.php(667): yii\BaseYii::autoload()
#3 /home/eurotools/public_html/vendor/yiisoft/yii2/base/Component.php(139): yii\web\Session->getIterator()

Additional info

This is because of missed return types of SessionIterator implements \Iterator:

public function current()

But \Iterator declare:

public function current(): mixed;

Q	A
Yii version	2.0.45
PHP version	8.1
Operating system	debian

[WinterSilence]

Hm.. I'm test it and can't find any problems https://3v4l.org/7ldOG#v8.1.6

[dicrtarasov]

This is the syntax error, it can not be no problem definitely.

[WinterSilence]

@dicrtarasov no syntax or any other errors are not detected. Extended class can omit parent's types.

[dicrtarasov]

Yes, generally children method can make return type narrow, but not wider. When no return type specified, it assume "mixed", which is widelly, then Iterator.

[dicrtarasov]

You can test it :) Parent -> child: mixed -> Iterator - Ok Iterator -> mixed - Error

Child can return only subclass of parent type compatibility.

[dicrtarasov]

As you can see, Error in this report is real. Try to google it.

[dicrtarasov]

PHP 8.1

[WinterSilence]

@dicrtarasov can you add tests to detect your error?

When no return type specified, it assume "mixed", which is widelly, then Iterator.

Большинство неокончательных внутренних методов теперь требуют переопределяющих методов для объявления совместимого возвращаемого типа, в противном случае во время проверки наследования выдаётся уведомление об устаревании возможности. В случае, если тип возвращаемого значения не может быть объявлен для метода переопределения из-за проблем совместимости версий PHP, можно добавить атрибут #[ReturnTypeWillChange], чтобы заглушить уведомление об устаревании. https://www.php.net/manual/ru/migration81.incompatible.php

[dicrtarasov]

Атрибут #[ReturnTypeWillChange] решит эту проблему.

[WinterSilence]

@dicrtarasov думаю тебе стоит обновится https://github.com/yiisoft/yii2/blob/6599713d2bcf4440190cec2b950b1738d7ddfae4/framework/web/SessionIterator.php#L62

[dicrtarasov]

Yii 2.0.45

[WinterSilence]

@bizley can be close, already fixed

[bizley]

Great.