Broadcasting data

You can send data to multiple WebSocket clients by calling the .broadcast() method on the WebSocket link matching those client connections:

import { ws } from 'msw'
 
const chat = ws.link('wss://chat.example.com')
 
export const handlers = [
  chat.addEventListener('connection', () => {
    chat.broadcast('Hello, everyone!')
  }),
]

Similar to the client.send() method, you can broadcast various data types.

This will send the same data to all intercepted WebSocket clients.

Examples

Excluding clients

You can exclude a specific client from the broadcast by using the broadcastExcept() method of the WebSocket link and providing it with the client instance to exclude:

import { ws } from 'msw'
 
const chat = ws.link('wss://chat.example.com')
 
export const handlers = [
  chat.addEventListener('connection', (client) => {
    client.addEventListener('message', (event) => {
      // Whenever this client sends a message,
      // broadcast it to all other clients.
      chat.broadcastExcept(client, event.data)
    })
  }),
]

You can also provide a list of clients as the first argument to the broadcastExcept() method to have a finer control over which clients get excluded from the broadcast:

chat.addEventListener('connection', () => {
  chat.broadcastExcept(
    chat.clients.filter((client) => {
      return client
    }),
    'Hello to some of you!',
  )
})

The clients property of your WebSocket link contains an array of all intercepted clients.