TestCase.php

<?php

class TestCase extends Illuminate\Foundation\Testing\TestCase
{
    /**
     * The base URL to use while testing the application.
     *
     * @var string
     */
    protected $baseUrl = 'http://samples.dev';

    /**
     * Setting up the test environment.
     */
    public function setUp()
    {
        parent::setUp();
        $this->configureDatabase();
    }

    /**
     * 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;
    }

    /**
     * Configure temporal database.
     */
    protected function configureDatabase()
    {
        $this->app['config']->set('database.default', 'sqlite');
        $this->app['config']->set('database.connections.sqlite.database', ':memory:');
    }

}