Laravel PHPunit AssertViewHas not seeing variables from base controller?

Question

PHPUnit

Here is the base controller code:

class BaseController extends Controller {
           public function __construct(){
                $base_config = array('base_url' => URL::to('/'));
    View::share('base_config', $base_config);
          }
}

Here is the controller code:

class MainController extends BaseController {
               public function index($id = 0){
    Log::info('This is some useful information.');
                $rating = Config::get('topic.index_good_topic_rating');
    $topics = Topic::getSubscribedTopics(Auth::user()->id, $rating);
    //echo "<pre>"; print_r($topics); echo "</pre>";exit;
    return View::make('main.index', array('topics' => $topics));
  }
}

Here is the test code:

public function testMainPage(){
    $this->be(User::find(1));
    $crawler = $this->call('GET', 'main/index');
    $this->assertViewHas(['topics']);
    $this->assertViewHas('base_config');

  }

Why doesn't the test see the variable from the base controller?