pws v2.0.0-alpha

PWS - PersistentWebSocket

npm install pws -S

WebSockets are great, but as soon as you start having a need for an always online connection (reconnecting) you either have to roll your own or pull in a big library like socket.io or primus. Both are great libraries, but maybe not really necessary for what you're doing.

This module gives you a reconnecting websocket to use in the browser or in node simply by switching out new WebSocket with new PersistentWebSocket.

• Tested with window.WebSocket
• Tested with uws
• Tested with ws

It behaves the same as a regular browser WebSocket, but reconnects automatically with a simple backoff algorithm when the connection closes. It also expects a heartbeat (any message will do) from the server every 30 seconds, or else it will close the connection and begin reconnecting (configurable).

The reason for doing a reconnect on a missing heartbeat from the server is because WebSockets doesn't close if the connection is not closed properly. This can often lead to stale connections. A server can implement the ping>pong from the WebSocket specification to ensure connections are still alive, but this doesn't solve the problem for clients. If doing a ping from the server it might be beneficial to include a timestamp and get some information on the connections latency.