collection.find() not working in NodeJS

There is something wrong with this colection.find().

What I am trying to do with the collection.find() code is, to determine if I have any duplicates before insertion.

I'm trying to log results.length to determine that.

 mongodb.Db.connect(process.env.MONGOHQ_URL, function(error, client) {
        if (error) {
          return log("Unable to connect to database: " + error);
        }
        client.collection("scores", function(error, collection) {
          var duplicate;

          if (error) {
            return log("Unable to access database: " + error);
          }
          if (!inputCheck(obj)) {
            return log("Input is invalid");
          }

          collection.find({
            game_title: obj.game_title,
            username: obj.username,
            score: obj.score
          }, function(error, cursor) {
              if (error) {
              return log("Unable to save record: " + error);
            }
              cursor.toArray(function(error,results) {
                  return log(results.length());
            });
          });