[HttpFoundation] Session::getBag($name) does not match Storage\SessionStorageInterface::getBag($name)

[patgrudniewski]

Symfony version(s) affected: 3.4.0 and higher

Description
There is getBag method at Symfony\Component\HttpFoundation\Session which calls $this->storage->getBag($name)->getBag().

As defined in constructor $this->storage is instance of Symfony\Component\HttpFoundation\Session\Storage\SessionStorageInterface which contains method getBag(string $name). As defined in comment it is expected that SessionStorageInterface::getBag(string $name) should return instance of Symfony\Component\HttpFoundation\Session\SessionBagInterface.

The problem is that SessionBagInterface does not contain getBag method so it's impossible to expect that $this->storage->getBag($name) will return object containing getBag() method.

How to reproduce

use Symfony\Component\HttpFoundation\Session\Attribute\AttributeBag;
use Symfony\Component\HttpFoundation\Session\Session;
use Symfony\Component\HttpFoundation\Session\Storage\MockArraySessionStorage;

$bag = new AtrributeBag();
$bag->setName('foo');

$storage = new MockArraySessionStorage();
$storage->registerBag($bag);

$session = new Session($storage);
$session->getBag('foo'); // this will effect with "Error: Call to undefined method Symfony\Component\HttpFoundation\Session\Attribute\AttributeBag::getBag()

Possible Solution
I'm not sure, probably removing second getBag call from Session::getBag($name).

[ro0NL]

i think we should test for SessionBagProxy first 👍

probably it's intended to use SessionInterface::registerBag() as main entrypoint (which wraps the bag)

[Simperfit]

@ro0NL what do you mean ?

[ro0NL]

There's a difference between registering a bag on the storage vs. on the session.

When registering a bag on the session it get's wrapped:

symfony/src/Symfony/Component/HttpFoundation/Session/Session.php

Lines 246 to 249 in 3bbf9da

	public function registerBag(SessionBagInterface $bag)
	{
	$this->storage->registerBag(new SessionBagProxy($bag, $this->data, $this->usageIndex));
	}

When you register thru MockArraySessionStorage it's not wrapped, however we call getBag($name)->getBag() from the Session which at this points expects a wrapped bag.

So i propose in Session::getBag() something like

return $bag instanceof SessionBagProxy ? $bag->getBag() : $bag;

[Simperfit]

Ok I understand now ! I think that’s a good idea ! I think the only way to be sure is by making a PR and see of people agree with you ;). ( I do) Le sam. 22 juin 2019 à 06:00, Roland Franssen <notifications@github.com> a écrit :

…

There's a difference between registering a bag on the storage vs. on the session. When registering a bag on the session it get's wrapped: https://github.com/symfony/symfony/blob/3bbf9da47bdf79d175f84a9a9c73a5d7d4f66beb/src/Symfony/Component/HttpFoundation/Session/Session.php#L246-L249 When you register thru MockArraySessionStorage it's not wrapped, however we call getBag($name)->getBag() from the Session which at this points expects a wrapped bag. So i propose in Session::getBag() something like return $bag instanceof SessionBagProxy ? $bag->getBag() : $bag; — You are receiving this because you commented. Reply to this email directly, view it on GitHub <#30682?email_source=notifications&email_token=AA2KV4QAXZB7GUUPXBP7RDLP3WPV3A5CNFSM4HA2YE5KYY3PNVWWK3TUL52HS4DFVREXG43VMVBW63LNMVXHJKTDN5WW2ZLOORPWSZGODYJ7SXA#issuecomment-504625500>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AA2KV4XK5R34EUHZZGCBNNDP3WPV3ANCNFSM4HA2YE5A> .

[xabbuh]

I agree with the reasoning here, see #32137