Class not found in _before function of Codeception TestCase

Question

Im writing some tests with Yii2 and Codeception and I'm getting a weird error when using my own class in the _before() function:

FATAL ERROR. TESTS NOT FINISHED.
Class 'app\lib\FTPImage' not found in /var/www/proyect/tests/codeception/unit/lib/FTPImageTest.php:13

It is strange because if I use it in a test method it works like charm :/

Here is the code of the test:

<?php
namespace tests\codeception\unit\lib;

use Yii;
use yii\codeception\TestCase;
use app\lib\FTPImage;

class FTPImageTest extends TestCase{

    public $ftp;

    public function _before(){
        $this->ftp = new FTPImage();
    }

    public function _after(){
    }

    public function testGetImagesNoImages(){
        $ftp = new FTPImage();

        $images = $ftp->getImages("123", "Foobar");

        $this->assertEmpty($images);
    }
}

And this is the code of the FTPImage class:

<?php
namespace app\lib;

use Yii;
use app\lib\FTPClient;
use \yii\base\Exception;
use \yii\base\ErrorException;
use \yii\imagine\Image;

class FTPImage{     

    public function __construct() {
    }

    public function getImages($reference, $supplier_name){
        ...
    }

I hope there's someone who can help me
Thanks in advance!

Answer 1

Finally I found the solution. I've changed to _before and _after functions to setUp and tearDown. This way, I can use my FTPImage class.

Here is what I did:

class FTPImageTest extends TestCase{

    public $ftp;

    public function setUp(){
        parent::setUp();
        $this->ftp = new FTPImage();
    }

    public function tearDown(){
        parent::tearDown();
    }

    ...
}