Blinchik

A tiny websocket wrapper that made using Kefir.js. It returns a Kefir stream instance.

Etymology

Blinchik — diminutive form of Blin. Blini frequently made using Kefir.

Getting started

0. Installation.

npm i -S blinchik

1. Look into examples.

• Simple counter example.
• Sessions usage example.
• Mock example.

You can also scale your code using Blinchik.

That's the client side:

import Blinchik from 'blinchik'

const b = new Blinchik('ws://127.0.0.1:8080')

const stream = b.onMsg({ shouldParseJSON: true })

const chatStream = stream
  .filter(({ data }) => data.type === 'CHAT/INCOMING_MESSAGE')

const notificationStream = stream
  .filter(({ data }) => data.type === 'NOTIFICATION/PAYMENT')

chatStream
  .log('chat stream')
  .map(({ data }) => {
    // your logic goes here
  })

notificationStream
  .log('notification stream')
  .map(({ data }) => {
    // your logic goes here.
    // e.g., you can show a popup with the notification
  })

And that's the server side:

import Blinchik from 'blinchik'

const b = new Blinchik({ port: 8080 })

const connectionsStream = b.onConn()

connectionsStream
  .onValue(({ conn }) => {
    // for demonstration purposes,
    // on each new connection we send
    // two messages to the client.
    // you can implement any custom logic instead.
    b.send({
      type: 'CHAT/INCOMING_MESSAGE',
      text: 'LMAO',
    }, conn)

    b.send({
      type: 'NOTIFICATION/PAYMENT',
      severity: 'error',
      text: 'Could not process scheduled payment. Please, review your billing settings.',
    }, conn)
  })

Using Blinchik, you can use all Kefir stream methods. See Kefir docs for more information.

2. You're ready to go ;)

API

Blinchik constructor parameters

new Blinchik(ws, settings)

ws must be one of:

• undefined (for creating mock instance)
• Blinchik instance (for using mock instance)
• String (node & browser client only): wss://ws.example.com/connections.
• Object (server only): WebSocket.Server options from ws library
• WebSocket or WebSocket.Server from ws library
• Standard WebSocket object

settings is an optional object with:

• disableReconnect (node & browser client only, Boolean, default: false): disables automatic failover behaviour, which will try to reconnect to a broken connection each reconnectInterval ms.
• reconnectInterval (node & browser client only, Number, default: 2000): failover reconnection interval in milliseconds.
• mock mock Blinchik instance or array mock Blinchik instances

Blinchik instance properties

ws eighter is one of:

• WebSocket or WebSocket.Server from ws library
• Standard WebSocket object

Blinchik instance will use this connection.

Blinchik methods for both server and clients

• onError(callback): sets error handler for current instance. Callback should accept an error. Error type depends on mode.
• onClose(callback): sets connection close handler for current instance. Callback should accept an error. Error type depends on mode.
• onMessage(options): returns Kefir stream of connection messages.
  • options is an optional object with shouldParseJSON boolean flag, that enables automatic data parsing.
• onMsg: alias for onMessage
• send(msg, ws): sends given message using current instance connection or given ws connection, if passed. This method handles connection state checks and automatic data stringify if given message is an object (which is not a valid WS message).

Blinchick client methods

• onOpen(callback): sets a handler which executed on successful connection.
• onPing(callback) (only node client): sets a handler for pings. For details, see ws library docs.

Blinchik server methods

• onConnection(): returns Kefir stream of new connections.
• onConn: alias for onConnection
• onHeaders(): returns Kefir stream which allows set custom headers. This is done by mutating headers property of the value.

Blinchik mock methods

• connect(): create mock connection

helpers

• setCookie(cookie)(params): helper for onHeaders stream.

cookie is object with:

• value?: string;
• expires?: string | Date;
• name?: string;
• isReplace?: boolean;
• ttl?: number;
• getValue?: () => string;
• getExpires?: () => string | Date;

params is object with:

• req: Request Object;
• headers: Array;