@getanthill/datastore/scripts/examples/mqtt-event.js

Event-Sourced Datastore

const MQTT = require('async-mqtt');

const client = MQTT.connect('tcp://localhost', {
  protocolVersion: 5,
  clean: true,
});

const doStuff = async () => {
  console.log('Starting');
  try {
    client.on('message', function (topic, message) {
      const entity = JSON.parse(message.toString());
      console.log(topic, entity);

      if (topic.startsWith('ds/accounts/created/success')) {
        // client.end();
        client.publish(
          `ds/accounts/updated/${entity.account_id}`,
          JSON.stringify({
            firstname: 'Bernard',
          }),
          {
            properties: {
              userProperties: {
                authorization: 'token',
              },
            },
          },
        );
      }

      if (topic === 'ds/accounts/updated/{account_id}/success') {
        client.end();
      }

      if (topic === 'ds/accounts/patched/{account_id}/success') {
        client.end();
      }
    });

    await client.subscribe('$share/group/ds/accounts/#');

    await client.publish(
      'ds/accounts/created/request',
      JSON.stringify({
        firstname: 'Alice',
        email: `alice+${(Math.random() * 1e12).toFixed(0)}@doe.org`,
        auth: 'auth',
      }),
      {
        properties: {
          userProperties: {
            authorization: 'token',
          },
        },
      },
    );

    // This line doesn't run until the server responds to the publish
    // await client.end();
    // This line doesn't run until the client has disconnected without error
    console.log('Done');
  } catch (e) {
    // Do something about it!
    console.log(e.stack);
    process.exit();
  }
};

client.on('connect', doStuff);