mimic-ws

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Mimic-ws is drop-in replacement for ws, powered by uWebSockets.js

Note: This module does not work in the browser.

Installing

npm install mimic-ws

#### Been a drop-in replacement, mimic-ws has some limits and difference:
- For SSL initialization you don't need separate HTTP server, just define certificate and key parameters, check examples.
- clientTracking is always true, and wss.clients is a Map, key is unique id, each ws has the same unique attribute id. No need to code own logic.
- Added backpressure event, so you can check that websocket is slow.
- Added drain event, so you can check that websocket buffer is free.
- Added publish/subscribe functions with MQTT topics support, check examples
- WebSocket handlers like onclose/onerror are removed. Use events.
- Use idleTimeout for dropping connections.
- Use maxBackpressure for dropping slow consumers.
- verifyClient parameters are bit different.

Usage examples

$3

``js
const WebSocket = require('mimic-ws')

const wss = new WebSocket.Server({
port: 8080
})

wss.on('connection', (ws) => {
ws.on('message', (message) => {
console.log('received: %s', message)
})

ws.send('something')
})
`

$3

`js
const WebSocket = require('mimic-ws')

const wss = new WebSocket.Server({
port: 8080,
sslCert: './test/fixtures/cert.pem',
sslKey: './test/fixtures/key.pem',
})

wss.on('connection', (ws) => {
ws.on('message', (message) => {
console.log('received: %s', message)
})

ws.send('something')
})
`

$3

A client WebSocket broadcasting to all connected WebSocket clients, including itself.

`js
const WebSocket = require('mimic-ws')

const wss = new WebSocket.Server({
port: 8080
})

wss.on('connection', (ws) => {
ws.on('message', (data) => {
wss.clients.forEach((client) => {
client.send(data)
})
})
})
`
A client WebSocket broadcasting to every other connected WebSocket clients, excluding itself.

`js
const WebSocket = require('mimic-ws')

const wss = new WebSocket.Server({
port: 8080
})

wss.on('connection', (ws) => {
ws.on('message', (data) => {
wss.clients.forEach((client, id) => {
if (ws !== client) { // or if (id.localeCompare(ws.id))
client.send(data)
}
})
})
})
`

$3


`js
const WebSocket = require('mimic-ws')

const wss = new WebSocket.Server({
port: 8080
})

wss.on('connection', (ws) => {
ws.subscribe('/house/#')

ws.publish('/house/room1')
ws.publish('/house/room2')
})
`

$3


`js
const WebSocket = require('mimic-ws')

const wss = new WebSocket.Server({
port: 8080
})

const handle = (ws, msg) => {
if (msg && msg.action) {
switch (msg.action) {
case 'publish':
ws.publish(msg.topic, JSON.stringify(msg.data))
break

case 'subscribe':
console.log(msg)
ws.subscribe(msg.topic)
break

case 'unsubscribe':
ws.unsubscribe(msg.topic)
break

default:
console.error(Unknown action: ${msg.action})
}
}
}

wss.on('connection', (ws) => {
ws.on('message', (message) => {
const msg = JSON.parse(message)
handle(ws, msg)
})
})

const publisher = new WebSocket(ws://localhost:${wss.address().port})
publisher.on('open', () => {
setInterval(() => {
const msg = {
action: 'publish',
topic: '/house/room1',
data: {
title: 'temperature in room1',
value: Math.floor(Math.random() * 30),
timestamp: Date.now()
}
}
publisher.send(JSON.stringify(msg))

const msg2 = {
action: 'publish',
topic: '/house/room2',
data: {
title: 'temperature in room2',
value: Math.floor(Math.random() * 30),
timestamp: Date.now()
}
}
publisher.send(JSON.stringify(msg2))
}, 1000)
})

const subscriber = new WebSocket(ws://localhost:${wss.address().port})
subscriber.on('open', () => {
const msg = {
action: 'subscribe',
topic: '/house/#'
}
subscriber.send(JSON.stringify(msg))
})

subscriber.on('message', (message) => {
console.log(got message: ${message})
})
`


#### Other examples
Check test cases.

#### Changelog
We're using the GitHub releases for changelog entries.

#### TODO
1. More tests
2. Typescript declaration
3. Benchmarks

$3


export DEBUG=mimic-ws*`

#### License
MIT

[npm-image]: https://img.shields.io/npm/v/mimic-ws.svg?logo=npm
[npm-url]: https://www.npmjs.com/package/mimic-ws

[ci-image]: https://github.com/mirpo/mimic-ws/workflows/Build/badge.svg
[ci-url]: https://github.com/mirpo/mimic-ws/actions

[coveralls-image]: https://coveralls.io/repos/github/mirpo/mimic-ws/badge.svg?branch=master
[coveralls-url]: https://coveralls.io/github/mirpo/mimic-ws