MathExecutor/tests/bootstrap.php

<?php

$vendorDir = __DIR__ . '/../../..';

if (\file_exists($file = $vendorDir . '/autoload.php')) {
    require_once $file;
} elseif (\file_exists($file = './vendor/autoload.php')) {
    require_once $file;
} else {
    throw new \RuntimeException('Not found composer autoload');
}