Sokil\Mongo\AggregatePipelinesTest::testPipeline_ToString PHP Method

    public function testPipeline_ToString()
    {
        $pipeline = new Pipeline($this->collection);
        // insert new match pipeline
        $pipeline->match(array('field1' => 'value1'));
        // insert new project pipeline
        $pipeline->project(array('field2' => 'value2'));
        // insert new match pipeline
        $pipeline->match(array('field3' => 'value3'));
        // append match pipeline to previous
        $pipeline->match(array('field3' => 'value3merged', 'field4' => 'value4'));
        // insert new sort pipeline
        $pipeline->sort(array('field5' => 'value5'));
        // insert new group pipeline
        $pipeline->group(array('_id' => '$groupField', 'field6' => array('$sum' => 1)));
        $validJson = '[{"$match":{"field1":"value1"}},{"$project":{"field2":"value2"}},{"$match":{"field3":"value3merged","field4":"value4"}},{"$sort":{"field5":"value5"}},{"$group":{"_id":"$groupField","field6":{"$sum":1}}}]';
        $this->assertEquals($validJson, $pipeline->__toString());
    }