ReplaceRoot not working with Doctrine

[aspire-shatheesh]

I am trying to achieve replaceRoot in doctrine. Seems there is some issue or am not sure if I am missing something.

[ 
{ "$unwind": "$data" }, 
{ "$match": { "$and": [ { "key": "885_2018_" } ] } }, 
{ "$group": { "_id": "null", "ranked": { "$push": "$data"  } } },
{ "$unwind": { "path": "$ranked", "includeArrayIndex": "rank" } },
{ "$addFields": {"ranked.rank": { $add: [ "$rank", 1] }} },
{ "$replaceRoot": { "newRoot": "$ranked" }  }
]);

I am trying to do the above mongo aggregation stage in Doctrine. Could you please help if this is a bug in Mongo ODM.

$builder = $this->createAggregationBuilder();
$groupByStage = $builder->group()->field('_id')->expression('null');
$groupByStage->field('ranked')->push('$data');
$groupByStage->unwind('$ranked')->includeArrayIndex('rank');
$builder->replaceRoot('$ranked');

I am getting the below error
'expected an object as specification for $replaceRoot stage, got string', 'stackTrace' => '#0 /api-r3/vendor/mongodb/mongodb/src/Operation/DatabaseCommand.php(94)

[alcaeus]

Yikes - that's not good. For ODM 1.x, this is fixed by doctrine/mongodb#333 as the error is actually in the doctrine/mongodb library. For 2.0, the fix will be ported to ODM directly. I'm closing this issue as it's being fixed in the respective libraries. Thanks for reporting it!

[aspire-shatheesh]

Thanks much @alcaeus

For now until #333 is merged, I did a workaround by passing an expression .

$expr = $builder->expr();
$expr->field('newRoot')->expression('$ranked');
$builder->replaceRoot($expr);

[alcaeus]

1.6.4 has been released, containing a fix 👍