My first unit test

<?php

class UserTest extends CDbTestCase {
    public $fixtures = array(
        'users' => 'User',
        'codes' => 'Code',
    );

    public $user_attrs = array(
        'user_name' => 'test_user',
        'password' => 'b59c67bf196a4758191e42f76670ceba',
        'email' => '[email protected]',
        'first_name' => 'FirstName',
        'last_name' => 'LastName',
        'city' => 'City',
    );

    public function testSetCode(){
        $code = $this->codes('not_used_code');
        $this->assertTrue($code instanceof Code);
        $this->assertFalse(!!$code->used);

        $user = new User();
        $user->attributes = array_merge($this->user_attrs, array('code' => $code->code));
        $this->assertTrue($user->save());
        $this->assertTrue($code->id == $user->code->id);
        $code->refresh();
        $this->assertTrue(!!$code->used);
    }
}