BookStack/tests/TestCase.php

<?php

use Illuminate\Foundation\Testing\DatabaseTransactions;

class TestCase extends Illuminate\Foundation\Testing\TestCase
{

    use DatabaseTransactions;

    /**
     * The base URL to use while testing the application.
     *
     * @var string
     */
    protected $baseUrl = 'http://localhost';
    private $admin;

    /**
     * Creates the application.
     *
     * @return \Illuminate\Foundation\Application
     */
    public function createApplication()
    {
        $app = require __DIR__.'/../bootstrap/app.php';

        $app->make(Illuminate\Contracts\Console\Kernel::class)->bootstrap();

        return $app;
    }

    public function asAdmin()
    {
        if($this->admin === null) {
            $this->admin = \BookStack\User::find(1);
        }
        return $this->actingAs($this->admin);
    }
}