async function in javascript with another call inside

Question

I have following node function for api server:

router.post('/find', async (req, res) => {
  try {
    const firewalls = [];
    let count = 0;
    const devices = await Device.find({ ...req.body });

    devices.forEach(async (item) => {
      const toObject = item.toJSON();
      const ping = await checkPing(integerToIp(toObject.ipAddress));
      console.log(ping);
      count++;
      firewalls.push({
        ...toObject,
        status: ping,
      });
    });

    if (count === devices.length) {
      res.json({ success: true, data: firewalls });
    }
  } catch (error) {}
});

and this function:

const ping = require('ping');

function checkPing(ipAddress) {
  return new Promise(async (resolve, reject) => {
    let result = {};
    if (ipAddress) {
      const res = await ping.promise.probe(ipAddress);

      result['alive'] = res.alive;
    }
    return resolve(result);
  });
}

in router.post i will get firewalls array as expected, but if ii want to add status property with result from checkPing function it wont save it. it will console.log just before but not in status property.

Iam sure iam missing something obvious but cant figure it out. Any help please?

console.log is asynchronous :/ – Lazar Nikolic Jun 18 '21 at 14:24 — Lazar Nikolic, Jun 18 '21 at 14:24

score 0 · Accepted Answer · answered Jun 18 '21 at 14:28

You can't await devices.forEach, use devices.map and await Promise.all instead.

router.post('/find', async (req, res) => {
  try {
    const firewalls = [];
    let count = 0;
    const devices = await Device.find({ ...req.body });

    await Promise.all(devices.map(async (item) => {
      const toObject = item.toJSON();
      const ping = await checkPing(integerToIp(toObject.ipAddress));
      console.log(ping);
      count++;
      firewalls.push({
        ...toObject,
        status: ping,
      });
    }));

    if (count === devices.length) {
      res.json({ success: true, data: firewalls });
    }
  } catch (error) {}
});

legend. thanks man :-) – Jakub Koudela Jun 18 '21 at 14:36 — Jakub Koudela, Jun 18 '21 at 14:36

score -1 · Answer 2 · answered Jun 18 '21 at 14:29

Use a for ... of loop instead. You cannot use forEach with async/await.

for (const item of devices) {
  const toObject = item.toJSON();
  const ping = await checkPing(integerToIp(toObject.ipAddress));
  console.log(ping);
  count++;
  firewalls.push({
    ...toObject,
    status: ping,
  });
});

async function in javascript with another call inside

2 Answers2