I wanto to get a length of an object using the mongoose lib

here is my code

const mongo = require("../../server") // model call
    
     {...}
    
    var query = 'email@email.com'; //get an email
        var db = mongo.connection;
        
        db.db.collection("user").findOne({email:query}, function(err, result) {
    
          if (err) throw err; 
          if ( result.length > 0) {...} // here I want to get my object length

In result.length Im getting an error because there's no length in my object , so someone know's how can I get it ?