Unit Testing with mcamara Localization

I'm using mcamara/laravel-localization package and I can't figure out how to make it work with my unit tests. Both of the following fail with red:

// 1. This one results in "Redirecting to http://myapp.dev/en"
$this->get('/')->assertSee('My App Homepage');

// 2. This one results in 404
$this->get('/en')->assertSee('My App Homepage');

In the browser, http://myapp.dev returns 302 with a redirect to http://myapp.dev/en, fair enough. However, http://myapp.dev/en returns 200. So both cases work 100% fine on the front-end, but not with unit tests.

I do have some customization however, which once again, works like charm in the browser.

// in web.php
Route::group([
    'prefix' => app('PREFIX'), // instead of LaravelLocalization::setLocale()
    'middleware' => ['localeSessionRedirect', 'localizationRedirect']],
    function() {
        Route::get('/', function() {
            return view('home');
        });
    }
]);

// in AppServiceProvider.php
public function boot()
{
    // This, unlike LaravelLocalization::setLocale(), will determine the 
    // language based on URL, rather than cookie, session or other
    $prefix = request()->segment(1); // expects 'en' or 'fr'
    $this->app->singleton('PREFIX', function($app) use ($prefix) {
        return in_array($prefix, ['en', 'fr']) ? $prefix : null;
    });
}

Hopefully this code makes sense to you. Thanks!

via Alex