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

An update to Xavier's answer:

db.collection.countDocuments({}, { limit: 1 })

Expects a callback as a second argument now, so this can be used instead:

db.collection.countDocuments({}).limit(1)