A WebSocket server library for Deno.
The raison d'être for this library is to provide a unified async iterator for the events of all connected WebSocket clients.
Note: This WebSocket server is not an EventEmitter (i.e. it does not use events with callbacks like websockets/ws). Instead, it specifies the asyncIterator symbol and should be used in conjunction with a for await...of loop, just like the Deno http server. The iterator return values are of
type WebSocketServerEvent = { event: WebSocketEvent; socket: WebSocket; };where socket is the WebSocket from which the data was received on.
import { serve } from "https://deno.land/x/websocket_server/mod.ts"; const server = serve(":8080"); for await (const { event } of server) { console.log(event); }import { listenAndServe } from "https://deno.land/x/websocket_server/mod.ts"; listenAndServe(":8080", ({ socket, event }) => { console.log(socket.conn.rid, event); });import { serve } from "https://deno.land/std@0.92.0/http/server.ts"; import { WebSocketServer } from "https://deno.land/x/websocket_server/mod.ts"; const httpServer = serve(":8080"); const wss = new WebSocketServer(httpServer); for await (const { event, socket } of wss) { console.log(event); if (!socket.isClosed) { socket.send("Hello, I am using the HTTP server!"); } }import { serve } from "https://deno.land/std@0.92.0/http/server.ts"; import { WebSocketServer } from "https://deno.land/x/websocket_server/mod.ts"; async function serverHandler(wss: WebSocketServer, message: string) { for await (const { event, socket } of wss) { console.log(event); if (!socket.isClosed) { socket.send(message); } } } const httpServer = serve(":8080"); const wss1 = new WebSocketServer(); const wss2 = new WebSocketServer(); serverHandler(wss1, "Received your message on server 1."); serverHandler(wss2, "Received your message on server 2."); for await (const req of httpServer) { if (req.url === "/foo") { wss1.handleUpgrade(req); } else if (req.url === '/bar') { wss2.handleUpgrade(req); } else { // Do stuff with your HTTP server e.g. close the connection await req.respond({ body: "You are not welcome!", status: 400, }); req.conn.close(); } }Check out the example echo/broadcast server.
This library provides a class only for WebSocket servers, not WebSocket clients, because it is straightforward to create clients with the WebSocket API.
Here is a simple example:
try { const socket = new WebSocket("ws://127.0.0.1:8080"); for await (const event of socket) { console.log(event); if (typeof event === "string" && event === "Who is this?") { socket.send("It is me, a simple WebSocket client."); } } } catch (err) { console.error(`Could not connect to WebSocket: '${err}'`); }Changelog entries can be found at releases.
- Thanks to zorbyte for helping me understand enough about async iterators to implement the server.
- The logo is based on "Dino in the Rain" by @kevinkassimo (MIT license).