Macbook power state alerting [Node.js]

index.js

'use strict';

const exec  = require('child_process').exec;
const https = require('https');

const API_KEY      = `*****`;
const PHONE_NUMBER = `7920*****`;

let state = 'Unknown';

setInterval(checkStatusAndUpdate, 500);

function checkStatusAndUpdate() {

    exec('pmset -g ps | head -1', (err, stdout, stderr) => {

        if (err) {
            console.error(`Error: ${err}`);
            return;
        }

        if (stderr) {
            console.error(`stderr: ${stderr}`);
            return;
        }

        let newState;

        if (stdout.indexOf('AC Power') > -1) {

            newState = `AC Power`;

        } else if (stdout.indexOf('Battery Power') > -1) {

            newState = `Battery Power`;

        } else {

            console.log(`stdout: ${stdout}`);

            newState = `Unknown`;
        }

        if (state !== newState) {

            notifyStateChanged({
                from: state,
                to: newState
            });

            state = newState;
        }
    });
}

function notifyStateChanged(options) {

    const msg = `State: ${options.from} -> ${options.to}`;

    console.log(msg);

    https.request({
        hostname: 'sms.ru',
        port: 443,
        path: `/sms/send?api_id=${API_KEY}&to=${PHONE_NUMBER}&msg=${encodeURIComponent(msg)}&json=1`,
        method: 'GET',
        headers: {'Content-Type': 'application/json'}
    }, res => {
        res.setEncoding('utf-8');
        res.on('data', data => {
            console.log(data);
        });
    }).on('error', err => {
        console.log('problem with request: ' + err.message);
    }).end();
}