function.js

exports = function(payload, response) {
  const mongodb = context.services.get('<your-service-name>');
  const collection = mongodb.db("<your-db-name>").collection("<your-collection-name>");
  
  var json = EJSON.parse(payload.body.text());
  var user = json.userId;
  var status = json.orderStatus;
  
  return collection
    .updateOne(
      {"body.userId": user}, 
      {$set: 
        {
          "body": json,
          "query": payload.query
        }
        
      },
      {upsert: true}
      )
    .then(result => {
      // result.matchedCount === 1;
      return result;
    });
};