parse-server aggregate function returns null result

Question

I am trying to use aggregate function on parse-server JS SDK

  var pipeline = [
    { group: { objectId: '$league_id'} }
  ];
  var query = new Parse.Query("Fixture");
  return query.aggregate(pipeline)
    .then(function (results) {
      return results;
    })
    .catch(function (error) {
      throw error;
    });

When I run this functions it gives correct number of groups for league_id but it contains null data

{
    "result": [
        {
            "objectId": null
        },
        {
            "objectId": null
        }
    ]
}

What I am missing in here ? What can I do for getting other fields in result

Answer 1

It seems like there is already an issue for this https://github.com/parse-community/parse-server/issues/5989#issuecomment-526007093

It is fixed in 3.9.0