WebSockets

Bun.serve({
	fetch(req, server) {
		// upgrade the request to a WebSocket
		if (server.upgrade(req)) {
			return; // do not return a Response
		}
		return new Response('Upgrade failed', {status: 500});
	},
	websocket: {}, // handlers
});

Bun.serve({
	fetch(req, server) {}, // upgrade logic
	websocket: {
		message(ws, message) {}, // a message is received
		open(ws) {}, // a socket is opened
		close(ws, code, message) {}, // a socket is closed
		drain(ws) {}, // the socket is ready to receive more data
	},
});

Bun.serve({
	fetch(req, server) {}, // upgrade logic
	websocket: {
		message(ws, message) {
			ws.send(message); // echo back the message
		},
	},
});

Bun.serve({
	fetch(req, server) {
		const sessionId = await generateSessionId();
		server.upgrade(req, {
			headers: {
				'Set-Cookie': `SessionId=${sessionId}`, 
			}, 
		});
	},
	websocket: {}, // handlers
});

type WebSocketData = {
	createdAt: number;
	channelId: string;
	authToken: string;
};

Bun.serve({
	fetch(req, server) {
		const cookies = new Bun.CookieMap(req.headers.get('cookie')!);

		server.upgrade(req, {
			// this object must conform to WebSocketData
			data: {
				createdAt: Date.now(),
				channelId: new URL(req.url).searchParams.get('channelId'),
				authToken: cookies.get('X-Token'),
			},
		});

		return undefined;
	},
	websocket: {
		// TypeScript: specify the type of ws.data like this
		data: {} as WebSocketData,
		// handler called when a message is received
		async message(ws, message) {
			// ws.data is now properly typed as WebSocketData
			const user = getUserFromToken(ws.data.authToken);

			await saveMessageToDatabase({
				channel: ws.data.channelId,
				message: String(message),
				userId: user.id,
			});
		},
	},
});

const socket = new WebSocket('ws://localhost:3000/chat');

socket.addEventListener('message', event => {
	console.log(event.data);
});

const server = Bun.serve({
	fetch(req, server) {
		const url = new URL(req.url);
		if (url.pathname === '/chat') {
			console.log(`upgrade!`);
			const username = getUsernameFromReq(req);
			const success = server.upgrade(req, {data: {username}});
			return success ? undefined : new Response('WebSocket upgrade error', {status: 400});
		}

		return new Response('Hello world');
	},
	websocket: {
		// TypeScript: specify the type of ws.data like this
		data: {} as {username: string},
		open(ws) {
			const msg = `${ws.data.username} has entered the chat`;
			ws.subscribe('the-group-chat');
			server.publish('the-group-chat', msg);
		},
		message(ws, message) {
			// this is a group chat
			// so the server re-broadcasts incoming message to everyone
			server.publish('the-group-chat', `${ws.data.username}: ${message}`);
		},
		close(ws) {
			const msg = `${ws.data.username} has left the chat`;
			ws.unsubscribe('the-group-chat');
			server.publish('the-group-chat', msg);
		},
	},
});

console.log(`Listening on ${server.hostname}:${server.port}`);

Bun.serve({
	websocket: {
		perMessageDeflate: true, 
	},
});