CreatesApplication.php

<?php

namespace Tests;

use Illuminate\Contracts\Console\Kernel;
use RuntimeException;

trait CreatesApplication
{
    protected $allowedHosts = ['', '127.0.0.1', 'localhost'];

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

        $app->make(Kernel::class)->bootstrap();

        $this->protectDatabase();

        return $app;
    }

    private function protectDatabase()
    {
        $host = config('database.connections.main.host');

        if (! in_array($host, $this->allowedHosts)) {
            throw new RuntimeException("$host not allowed. Please change your phpunit.xml setup.");
        }
    }
}