public function testAggregate()
{
$pipeline = [['$match' => ['status' => 'A']], ['$group' => ['_id' => '$cust_id', 'total' => ['$sum' => 'amount']]]];
$result = [['_id' => 'a1', 'total' => 321], ['_id' => 'a2', 'total' => 87]];
$collection = $this->getMockBuilder('\\MongoDB\\Collection')->disableOriginalConstructor()->getMock();
$collection->expects($this->once())->method('aggregate')->with($pipeline)->will($this->returnValue($result));
$repository = new RepositoryMock($this->mandango);
$repository->setCollection($collection);
$repository->aggregate($pipeline);
}
