keepAlive property

Duration keepAlive

The timout between dispatched keep-alive messages, naimly server pings. Internally dispatches the PingMessage type to the server and expects a PongMessage in response. This helps with making sure that the connection with the server is alive and working.

Timeout countdown starts from the moment the socket was opened and subsequently after every received PongMessage.

Note that NOTHING will happen automatically with the client if the server never responds to a PingMessage with a PongMessage. If you want the connection to close, you should implement your own logic on top of the client. A simple example looks like this:

import { createClient } from 'graphql-ws';

let activeSocket, timedOut;
createClient({
  url: 'ws://i.time.out:4000/after-5/seconds',
  keepAlive: 10_000, // ping server every 10 seconds
  on: {
    connected: (socket) => (activeSocket = socket),
    ping: (received) {
      if (!received) // sent
        timedOut = setTimeout(() {
          if (activeSocket.readyState == WebSocket.OPEN)
            activeSocket.close(4408, 'Request Timeout');
        }, 5_000); // wait 5 seconds for the pong and then close the connection
    },
    pong: (received) {
      if (received) clearTimeout(timedOut); // pong is received, clear connection close timeout
    },
  },
});

@default Duration.zero

Implementation

final Duration keepAlive;