Laravel 5.1 unit testing with session - laravel

Question

Given this test:
echo "\n";
echo Session::getId();
$this->call('GET', '/');
echo "\n";
echo Session::getId();
The output shows that the Session ID is not persisted after the request:
fb7e02798f043fac798a424547f0d01acd0dbdc0
83133c07abdbba5bc32f74eaf14362a69406ca45
As far as I can tell they should be the same, app/config/session settings
'driver' => env('SESSION_DRIVER', 'file'),
'lifetime' => 120,
'expire_on_close' => false,
'domain' => "test.com",
The same tests works in 4.2, not entirely sure if there is an additional requirement to use sessions in unit tests or I should be using the facade implementations.
edit: 0 session issues browsing normally on the site
phpunit.xml
<env name="APP_ENV" value="local"/>
<env name="CACHE_DRIVER" value="file"/>
<env name="SESSION_DRIVER" value="file"/>
<env name="QUEUE_DRIVER" value="sync"/>

Answer 1

Unit testing is about testing single classes
I think the intention of unit testing is not fully understood in this example.
Unit testing is not about touching classes you don't want to test. Therefor it should not include third party libraries or resources and it should be about just one class.
Every other code dependency should be implemented with a test double.
If I would include the concrete session in my unit test, I would actually test that object too. Why would I? It means that if Laravel changes the session implementation, I would have to change my unit tests.
Which would mean I would lose the advantage of the unit test, because it should be about change that happens to just one class. With losing the advantage I will lose the benefit of the test, to see if other classes still work after a change.
Integration testing
The visit method is more like integration testing, since it loads the routing mechanism, controller and other dependencies defined in the controller.
You can manage the session data by setting up the expected values for each test case (or test method).
For example, if you have a checkout process which contains a form in each checkout step:
public function testFormStep1()
{
//$this->visit...
}
public function testFormStep2()
{
$this->session([
//... data from step 1 you need in step 2
]);
//$this->visit...
}
In this way you have control over each test case. You don't want to depend on other test cases, test should be done in isolation.
So for example, if step 1 of a form can only pass to step 2 when all form fields are present, you can simply make another test case which simulates fields are left empty in step 1:
public function testFormStep2Error()
{
$this->session([
//... incomplete data from step 1
]);
//... verify form step 2 should do something when form in step 1 is not completed
}
Selenium
Another option is Selenium, which exists more at the level of the system, because it includes a browser and goes through the web server with an HTTP request. The session is bound to the browser by a session cookie (and id). In this way you can preserve the session for each request.

Answer 2

Unit tests run in CLI/terminal/commandline. Cli does not work with persistent sessions.
When running tests, Laravel will automatically set the configuration environment to testing. Laravel automatically configures the session and cache to the array driver while testing, meaning no session or cache data will be persisted while testing.
See: http://laravel.com/docs/5.1/testing
Actually this is almost the same message as in version 4.2. So no idea how you could have made persistent sessions in unit tests before.