MoscaRetain.js

/*

Simple test for Mosca retain flag

  - Creates a Mosca server
  - Connects mqtt.js client when ready
  - sends a random message with retain flag
  - subscribes to the topic after sending
  - checks if received message is the correct one
  - checks ifd retain flag is set

Sample Output:

Received correct random message with value 178495
Packet {
  cmd: 'publish',
  retain: false,    <---- should be true
  qos: 0,
  dup: false,
  length: 13,
  topic: '/test',
  payload: <Buffer 31 37 38 34 39 35> }

*/

const Mosca = require('mosca')
const MQTT = require('mqtt')

let client = null

let url = 'ws://localhost:1884'
// To test with mosquitto:
// let url = 'ws://test.mosquitto.org:8080'

const server= new Mosca.Server({
  http: {
    port: 1884 
  },
  persistence: {
    factory: Mosca.persistence.Memory
  }
});
server.on('ready', () => { 
  let randomMessage = '' + Math.floor((Math.random() * 1000000));
  client = MQTT.connect(url)
  client.on('connect', () => {
    client.on('message', (topic, message, packet) => {
      if (randomMessage === message.toString()) {
        console.log('Received correct random message with value ' + message.toString())
      }
      console.log(packet);
      client.end()
      server.close()
    })
    client.publish('/test', randomMessage, { retain: true })
    setTimeout(() => {
      client.subscribe('/test')
    }, 1000)
  });
});