DatabaseTruncate.php

<?php namespace Testing\Traits;

trait DatabaseTruncate
{
    /**
     * Define hooks to truncate the database before each test.
     *
     * @return void
     */
    public function runTruncateDatabase()
    {
        $this->artisan('testing:truncate-db');
    }
}

DeleteContentTestingDatabase.php

<?php namespace App\Console\Commands\Testing;

use Illuminate\Console\Command;
use Illuminate\Support\Facades\DB;

class DeleteContentTestingDatabase extends Command
{
    /**
     * The name and signature of the console command.
     *
     * @var string
     */
    protected $signature = 'testing:truncate-db';

    /**
     * The console command description.
     *
     * @var string
     */
    protected $description = 'Running before each test, making sure the content of the testing db is reset';

    /**
     * Create a new command instance.
     *
     * @return void
     */
    public function __construct()
    {
        parent::__construct();
    }

    /**
     * Execute the console command.
     *
     * @return mixed
     */
    public function handle()
    {
        DB::statement("SET foreign_key_checks=0");
        $tables = DB::select("SELECT TABLE_NAME as name FROM INFORMATION_SCHEMA.TABLES where  table_schema in ('i-heart-reading-testing')");
        collect($tables)->each(function($item) {
           DB::statement("TRUNCATE ".$item->name.";");
        });
        DB::statement("SET foreign_key_checks=1");

    }
}

TestCase.php

<?php

use Testing\Traits\DatabaseTruncate;

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

    /**
     * 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 setUpTraits()
    {
        parent::setUpTraits();

        $uses = array_flip(class_uses_recursive(static::class));

        if (isset($uses[DatabaseTruncate::class])) {
            $this->runTruncateDatabase();
        }
    }
}