public function test_accessorsConnection()
 {
     /** === Test Data === */
     $CONN_NAME = 'connection name';
     $CONN = 'connection';
     /** === Setup Mocks === */
     // $this->_conn = $this->_resource->getConnectionByName($this->_nameConn);
     $mConn = $this->_mockConn();
     $this->mResource->shouldReceive('getConnectionByName')->once()->andReturn($mConn);
     /** === Call and asserts  === */
     $res = $this->obj->getConnection($CONN_NAME);
     $this->assertTrue($res instanceof \Magento\Framework\DB\Adapter\AdapterInterface);
     $this->obj->setConnection($CONN);
     $res = $this->obj->getConnection();
     $this->assertEquals($CONN, $res);
 }
<?php

require_once __DIR__ . '/../vendor/autoload.php';
require_once dirname(__FILE__) . '/../config/db.php';
require_once dirname(__FILE__) . '/../src/Item.php';
require_once dirname(__FILE__) . '/../src/User.php';
require_once dirname(__FILE__) . '/../src/Admin.php';
require_once dirname(__FILE__) . '/../src/Order.php';
require_once dirname(__FILE__) . '/../src/Message.php';
$conn = new mysqli(DB_HOST, DB_USER, DB_PASSWORD, DB_DB, DB_PORT);
if ($conn->connect_error) {
    $error = $conn->connect_error . '(' . $conn->connect_errno . ')';
    echo $error;
} else {
    $conn->set_charset('utf8');
}
//tworzymy nowy obiekt AltoRouter
$router = new AltoRouter();
//z db.php bierzemy base_path, ktory jest naszym katalogiem glownym po ktorym bedziemy otrzymywac ladne slashe
$router->setBasePath(BASE_PATH);
include dirname(__FILE__) . '/../routing.php';
$match = $router->match();
//uruchamia nam nasz router i automatycznie dodaje go do kazdej podstrony
if ($match) {
    require '../' . $match['target'];
}
User::setConnection($conn);
Admin::setConnection($conn);
Item::setConnection($conn);
Order::setConnection($conn);
Message::setConnection($conn);