javascript - Meteor server method returns undefined in callback -

how can server methods response in client ? when call server method , console.log on response, gives me "undefined" on client, on terminal, returns value expected.

my meteor version meteor 1.3.2.4

method on server

meteor.methods({     testmethodonprod : (arg) => {         console.log("in prod ", arg)         return meteor.userid()     } }) 

calling method on client.

meteor.call("testmethodonprod","some text on prod",(err,res)=> {     console.log("err ",err)     console.log("res ",res) }) 

console.log on client (browser) returns

err  undefined res  undefined 

console.log in terminal returns

err  undefined res  <user_id_here> 

try on client:

meteor.call("testmethodonprod","some text on prod",(err,res)=> {    !err ? console.log(res) : console.log(err); })