Twig functional tests for extensions

Code
<?php

// content of file Fixtures/filter/myfilter.test
/*
--TEST--
"myfilter" filter test
--TEMPLATE--
{{ foo|myfilter }}
{{ notfoo|myfilter }}
--DATA--
return ['foo' => 'this is foo', 'notfoo' => 'nothing changed']
--EXPECT--
this is bar
nothing changed
*/

class TwigExtensionTest extends Twig\Test\IntegrationTestCase
{
    public function 
getExtensions()
    {
        return [
            new 
MyExtension(),
        ];
    }
    
    public function 
getFixturesDir()
    {
        
$path __DIR__ '/Fixtures/';

        return 
$path;
    }
}

class 
MyExtension extends Twig\Extension\AbstractExtension
{
    public function 
getFilters()
    {
        return [
            new 
Twig\TwigFilter('myfilter', function ($value) {
                return 
str_replace('foo''bar'$value);
            }),
        ];
    }
    
    public function 
getName()
    {
        return 
'myextension';
    }
}
Result
Time: 00:00.012, Memory: 18.00 MB

OK, but incomplete, skipped, or risky tests!
Tests: 2, Assertions: 0, Skipped: 1.
Used Versions
PHP 8.2, Laminas MVC 3.2, Symfony 5.2, Laravel 8.28, PHPUnit 9.5, Doctrine ORM 2.8