Example TestCase using Laravel 8 model factories

TestCase.php

<?php

namespace Tests;

use Illuminate\Database\Eloquent\Factories\Factory;
use Illuminate\Foundation\Testing\TestCase as BaseTestCase;
use Illuminate\Support\Str;

abstract class TestCase extends BaseTestCase
{
    use CreatesApplication;

    // Our codebase is structured by domain, so our models live
    // in nested directories rather than App/Models e.g.

    // App/Domain/Posts/Models/Post
    // App/Domain/Posts/Models/Comment

    public function setUp(): void
    {
        parent::setUp();

        Factory::guessFactoryNamesUsing(function (string $modelName) {
            // We can also customise where our factories live too if we want:
            $namespace = 'Database\\Factories\\';

            // Here we are getting the model name from the class namespace
            $modelName = Str::afterLast($modelName, '\\');

            // Finally we'll build up the full class path where
            // Laravel will find our model factory
            return $namespace.$modelName.'Factory';
        });
    }
}