onAuthentication example

        if ($previousToken = $event->getPreviousToken()) {
            $user = $token->getUserIdentifier();
            $previousUser = $previousToken->getUserIdentifier();

            if ('' !== ($user ?? '') && $user === $previousUser) {
                return;
            }
        }

        $this->sessionAuthenticationStrategy->onAuthentication($request, $token);
    }

    public static function getSubscribedEvents(): array
    {
        return [LoginSuccessEvent::class => 'onSuccessfulLogin'];
    }
}

use Symfony\Component\Security\Csrf\TokenStorage\ClearableTokenStorageInterface;
use Symfony\Component\Security\Http\Session\SessionAuthenticationStrategy;

class SessionAuthenticationStrategyTest extends TestCase
{
    public function testSessionIsNotChanged()
    {
        $request = $this->getRequest();
        $request->expects($this->never())->method('getSession');

        $strategy = new SessionAuthenticationStrategy(SessionAuthenticationStrategy::NONE);
        $strategy->onAuthentication($request, $this->createMock(TokenInterface::class));
    }

    public function testUnsupportedStrategy()
    {
        $this->expectException(\RuntimeException::class);
        $this->expectExceptionMessage('Invalid session authentication strategy "foo"');
        $request = $this->getRequest();
        $request->expects($this->never())->method('getSession');

        $strategy = new SessionAuthenticationStrategy('foo');
        $strategy->onAuthentication($request, $this->createMock(TokenInterface::class));
    }