Add custom developement server

This implements a tiny WebSocket proxy useful for development
purposes.

dev-server.js

@@ -0,0 +1,61 @@
+import * as http from "http";
+import * as tls from "tls";
+import split from "split";
+import { Server as StaticServer } from "node-static";
+import { WebSocketServer } from "ws";
+
+const WS_BAD_GATEWAY = 1014;
+
+let localPort = 8080;
+let remoteHost;
+let remotePort = 6697;
+
+let args = process.argv.slice(2);
+if (args[0] === "-p") {
+	localPort = parseInt(args[1], 10);
+	args = args.slice(2);
+}
+remoteHost = args[0];
+
+let staticServer = new StaticServer(".");
+
+let server = http.createServer((req, res) => {
+	staticServer.serve(req, res);
+});
+
+if (remoteHost) {
+	let wsServer = new WebSocketServer({ server });
+	wsServer.on("connection", (ws) => {
+		let client = tls.connect(remotePort, remoteHost, {
+			ALPNProtocols: ["irc"],
+		});
+
+		ws.on("message", (data) => {
+			client.write(data.toString() + "\r\n");
+		});
+
+		ws.on("close", () => {
+			client.destroy();
+		});
+
+		client.pipe(split()).on("data", (data) => {
+			ws.send(data.toString());
+		});
+
+		client.on("end", () => {
+			ws.close();
+		});
+
+		client.on("error", () => {
+			ws.close(WS_BAD_GATEWAY);
+		});
+	});
+}
+
+server.listen(localPort, "localhost");
+
+let msg = "HTTP server listening on http://localhost:" + localPort;
+if (remoteHost) {
+	msg += " and proxying WebSockets to " + remoteHost;
+}
+console.log(msg);