index.js

#!/usr/bin/env node

const ScaledroneWS = require('scaledrone-node');
const ScaledroneREST = require('scaledrone-node-push');
const crypto = require('crypto');

const CHANNEL_ID = process.env.CHANNEL_ID || 'rAs7cOdHUbHWXlpv';
const SECRET = process.env.CHANNEL_SECRET || 'NicsuJZlEp0EbLCjhppyUeOt8k8e0lQj';
const ROOM = 'ping';
const INTERVAL_MS = 1000;

if (!CHANNEL_ID || !SECRET) {
  console.error('Set CHANNEL_ID and CHANNEL_SECRET');
  process.exit(1);
}

const rest = new ScaledroneREST({ channelId: CHANNEL_ID, secretKey: SECRET });
const ws = new ScaledroneWS(CHANNEL_ID);
const room = ws.subscribe(ROOM);

const inflight = new Map(); // id -> t0 (ns)

function nowNs() { return process.hrtime.bigint(); }
function toMs(ns) { return Number(ns) / 1e6; }
function id() { return crypto.randomBytes(8).toString('hex'); }

let timer = null;

function sendOnce() {
  const msgId = id();
  inflight.set(msgId, nowNs());
  const msg = JSON.stringify({ id: msgId });
  // console.log('Publishing', msgId);
  rest.publish(ROOM, msg, (err) => {
    if (err) {
      console.error('REST publish error:', err.message || err);
    } else {
      // console.log('Published', { id: msgId });
    }
  });
}

room.on('open', (err) => {
  if (err) {
    console.error('Room open error:', err.message || err);
    process.exit(2);
  }
  console.log(`channel=${CHANNEL_ID} room=${ROOM} interval=${INTERVAL_MS}ms`);
  timer = setInterval(sendOnce, INTERVAL_MS);
});

room.on('message', (m) => {
  // console.log('GOT DATA:', m);
  let data = m && m.data;
  if (!data) return;
  if (typeof data === 'string') {
    try { data = JSON.parse(data); } catch (_) {}
  }
  const msgId = data && data.id;
  const t0 = msgId && inflight.get(msgId);
  if (!t0) return;

  inflight.delete(msgId);
  const rttMs = toMs(nowNs() - t0);
  console.log(`${new Date().toISOString()} id=${msgId} rtt=${rttMs.toFixed(2)}ms`);
});

ws.on('error', (e) => console.error('WS error:', e.message || e));
ws.on('close', () => {
  if (timer) clearInterval(timer);
  console.warn('WS closed');
});

process.on('SIGINT', () => {
  if (timer) clearInterval(timer);
  try { ws.close && ws.close(); } catch (_) {}
  process.exit(0);
});