Having issue with Symfony 3 Unit testing that has session enabled

I am new in unit testing. I have Symfony 3 console command application which is using symfony session for temporary data store.

In my unit test class I extend KernelTestCase which give me error while I tested it but if I extend Symfony\Component\HttpKernel\EventListener\TestSessionListener class then the error gone and passed the test.

After some time I realize that it always passed test no mater what I write inside the test case.

My Console class

protected function execute(InputInterface $input, OutputInterface $output)
    {
        // Retrieve the argument value using getArgument()
        $csv_name = $input->getArgument('file');

        // Check file name
        if ($csv_name == 'input.csv') {
            // Get input file from filesystem
            $csvData = array_map('str_getcsv', file($this->base_path.'/../web/'.$csv_name));
            $formatData = Helpers::formatInputData($csvData);

            // Start session
            $session = new Session();
            $session->start();

            foreach ($csvData as $key => $data) {
                if (!empty($data[0])) {
                    $validation = Validator::getInformationData($data, $formatData[$data[1]]);
                    if (!empty($validation)) {
                        $output->writeln($validation);
                    } else {
                        $output->writeln('valid');
                    }
                }
            }
        } else {
            $output->writeln('Invalid file!');
        }
    }

My test case

use Symfony\Component\HttpKernel\EventListener\TestSessionListener as BaseTestSessionListener;

class DocumentCommandTest extends BaseTestSessionListener
{
    /**
     * Test Execute
     *
     */
    public function testExecute()
    {
        $kernel = static::createKernel();
        $kernel->boot();

        $application = new Application($kernel);
        $application->add(new DocumentCommand($kernel->getContainer()));

        $command = $application->find('identification-requests:process');
        $commandTester = new CommandTester($command);
        $commandTester->execute(array(
            'command' => $command->getName(),
            'file' => 'input.csv'
        ));

        $output = $commandTester->getOutput();
        $this->assertContains('valid',$output);
    }
}

After that I also tried to extend Symfony\Bundle\FrameworkBundle\Tests\Functional\SessionTest

use Symfony\Bundle\FrameworkBundle\Tests\Functional\SessionTest;

class DocumentCommandTest extends SessionTest
{

but it give me the following error

E.........                                                        10 / 10 (100%)

Time: 4.72 seconds, Memory: 20.00MB

There was 1 error:

1) Tests\AppBundle\Command\DocumentCommandTest::testExecute
InvalidArgumentException: The option "test_case" must be set.

My expected output from console is the following that needs to be tested

$ php bin/console identification-requests:process input.csv
valid
valid
valid
document_number_length_invalid
request_limit_exceeded
valid
document_is_expired
valid
document_type_is_invalid
valid
valid
document_number_invalid
valid
document_issue_date_invalid

Try removing

$output = $commandTester->getOutput();
$this->assertContains('valid',$output);

and add:

        $expected = 'valid
valid
valid
document_number_length_invalid
request_limit_exceeded
valid
document_is_expired
valid
document_type_is_invalid
valid
valid
document_number_invalid
valid
document_issue_date_invalid
';
        $testresult = $commandTester->getDisplay();

        $this->assertEquals($expected, $testresult);

see: http://www.inanzzz.com/index.php/post/c7jb/testing-symfony-console-command-with-phpunit