✅ Set up traits dynamically for tests

ArticleUpdateTest.php

<?php

namespace Tests;

use Tests\Authenticated;
use Illuminate\Support\Facades\Auth;
use Illuminate\Foundation\Testing\RefreshDatabase;

class ArticleUpdateTest extends TestCase
{
    use RefreshDatabase;
    use Authenticated;

    /** @test */
    public function authenticated_users_can_update_articles()
    {
        // User is already authenticated and accessible via $this->user.
        $this->assertTrue(Auth::check());
        $this->assertNotNull($this->user);
    }
}

Authenticated.php

<?php

namespace Tests;

use App\User;

trait Authenticated
{
    protected $user;

    // This will be automatically set up on test classes that uses this trait.
    public function setUpAuthenticated()
    {
        $this->user = factory(User::class)->create();
        $this->actingAs($this->user);
    }
}

TestCase.php

<?php

namespace Tests;

use Illuminate\Foundation\Testing\TestCase as BaseTestCase;

abstract class TestCase extends BaseTestCase
{
    use CreatesApplication;

    protected function setUp(): void
    {
        // Set up traits dynamically.
        // Uses the naming convention: "setUpNameOfMyTrait".
        $this->afterApplicationCreated(function () {
            foreach (class_uses_recursive($this) as $trait) {
                if (method_exists($this, $method = 'setUp' . class_basename($trait))) {
                    call_user_func([$this, $method]);
                }
            }
        });

        parent::setUp();
    }
}

@Naoray Yeah, I use to override that instead but I recently found out about afterApplicationCreatedCallbacks and I thought that was more robust than overriding a protected method.

Also parent::setUpTraits() returns an array of traits flipped. Which means you should use the key instead of the value when looping through them.

protected function setUpTraits()
{
    $uses = parent::setUpTraits();

    foreach($uses as $trait => $flippedIndex) {
        if (method_exists($this, $method = 'setUp' . class_basename($trait))) {
            call_user_func([$this, $method]);
        }
    }

    return $uses;
}