How to query MongoDB to test if an item exists?

Question

Does MongoDB offer a find or query method to test if an item exists based on any field value? We just want check existence, not return the full contents of the item.

Answer 1

Im currently using something like this:

async check(query) {
  const projection = { _id: 1 };

  return !!db.collection.findOne(query, projection);
}

It will return true or false, of course returning only _id: 1 for smallest data transfer.