adding a field to a user after created - meteor

Question

This code attempts to add a field to a user which already exist in meteor users.
The error I am getting is
Exception while invoking method 'logMeIn' Error: insert requires an argument
Which I don't understand, how can it be fixed? Thanks
/////////////////////////////////////
// client code
/////////////////////////////////////
Template.login.events({
'click #logMe': function() {
var username = $('#id').val();
var password = $('#pin').val();
Meteor.call('logMeIn', [username,password], function (err, data) { //create new user
if ( err ) {
if (err.message.match(/username already exists/i)) {
Meteor.loginWithPassword(username+password,password)
}
} else {
console.log('new user created');
}
});
}
});
/////////////////////////////////////
// server code
/////////////////////////////////////
Meteor.methods({
logMeIn: function (credentials) {
//do work , if logged in, do next line
var idPin = credentials[0] + credentials[1];
Accounts.createUser({username: idPin, password: credentials[1]});
}
});
Accounts.onCreateUser(function (options, user) {
user.menuGroup = 'a';
});

Answer 1

You need to return the user on the Account.onCreatedUser (documentation here). Also, additional data of the user should be put under the profile branch (check the documentation in here)
Accounts.onCreateUser(function (options, user) {
if (options.profile) {
user.profile = options.profile;
}
if (user['profile'] == null) {
user['profile'] = {};
}
user['profile']['menuGroup'] = 'a';
return user;
});