/**
* test WHERE conditions against unary expression.
*
* @return void
*/
public function testUnaryExpression()
{
$this->table->addColumn('user-birth-date', ['type' => 'date'], false);
$first = $this->table->get(1);
$first->set('user-birth-date', time());
$this->table->save($first);
$second = $this->table->find('all', ['eav' => true])->where(['user-birth-date IS' => null])->order(['id' => 'ASC'])->first();
$this->assertTrue(!empty($second) && $second->get('id') == 2);
}