get_my/imports/api/userConfig.js

import { Meteor } from 'meteor/meteor';
import { Mongo } from 'meteor/mongo';
import { check } from 'meteor/check';

export const UserConfig = new Mongo.Collection('userConfig');

UserConfig.allow({
    insert: function(userId, doc){
        // if use id exists, allow insert
        return !!userId;
    },
});

Meteor.methods({
    'add.darkModePref' (pref) {
        check(pref, String);

        if (!this.userId) {
            throw new Meteor.Error('Not able to change registration setting. Make sure you are logged in with valid system administrator credentials.');
        }

        return UserConfig.insert({
            user: this.userId,
            darkMode: pref,
            dateAdded: Date()
        });
    },
    'update.darkModePref' (pref) {
        check(pref, String);

        if (!this.userId) {
            throw new Meteor.Error('Not able to change registration setting. Make sure you are logged in with valid system administrator credentials.');
        }

        return UserConfig.update({ user: this.userId }, {
            $set: {
                darkMode: pref,
                dateUpdate: Date()
            }
        });
    }
});