Put that under tests/functionnal/PurchaseMasterBoxTest.php

PurchaseMasterBoxTest.php

<?php

use Illuminate\Foundation\Testing\WithoutMiddleware;
use Illuminate\Foundation\Testing\DatabaseMigrations;
use Illuminate\Foundation\Testing\DatabaseTransactions;

use Faker\Factory as Faker;

class PurchaseMasterBoxTest extends TestCase
{

  // This is important, don't forget it.
  // By default the tests are runned against the database you are working on.
  // Every call to the database from your tests are wrapped into a transaction
  // like that we don't put the mess in it. 
  use DatabaseTransactions;

  /** @test */
  public function auto_connect_user_and_visit_his_account()
  {

    // Create one customer (you can change 1 to X to change the number of customers created)
    // You can set an array in create() if you want to override some entries (like first_name, last_name, etc ..)
    // In our case we need to know what's the email and the password to use it when we will connect. So I pass 
    // email and password in it.
    $customer = factory(App\Models\Customer::class, 1)->create([
      'email' => 'awesome@domain.com',
      'password' => Hash::make('jeremie')
    ]);

    // Auto connect the user created
    Auth::guard('customer')->attempt(['email' => 'awesome@domain.com', 'password' => 'jeremie']);

    // Check if we can see the profile
    $this->visit('/customer/profile')
      ->seePageIs('/customer/profile');

    // That's all


  }

}