public function testAddToSet_CallableExpression()
{
$pipeline = new Pipeline($this->collection);
$pipeline->group(function ($stage) {
/* @var $stage \Sokil\Mongo\Pipeline\GroupStage */
$stage->setId('$userId')->addToSet('totalAmount', function ($expression) {
/* @var $expression \Sokil\Mongo\Pipeline\Expression */
$expression->add('$amount', 12);
});
});
$this->assertEquals('[{"$group":{"_id":"$userId","totalAmount":{"$addToSet":{"$add":["$amount",12]}}}}]', (string) $pipeline);
}