feat(server): scaffold Bun HTTP+WS server with health + logging (P4.1)

packages/server/package.json

@@ -11,5 +11,8 @@
     "@paratype/rete": "workspace:*",
     "pino": "^9.0.0",
     "zod": "^3.23.0"
+  },
+  "devDependencies": {
+    "bun-types": "^1.3.12"
   }
 }

packages/server/src/index.ts

@@ -1,2 +1,53 @@
 // @paratype/chess-server — authoritative Bun WebSocket server
-export {};
+import { randomUUID } from "node:crypto";
+import { logger } from "./logger.js";
+
+interface ClientData {
+  clientId: string;
+}
+
+const port = parseInt(process.env["PORT"] ?? "7357", 10);
+
+export const server = Bun.serve<ClientData>({
+  port,
+  fetch(req, srv) {
+    const url = new URL(req.url);
+
+    if (url.pathname === "/ws") {
+      const upgraded = srv.upgrade(req, {
+        data: { clientId: randomUUID() },
+      });
+      if (upgraded) return undefined;
+      return new Response("Upgrade failed", { status: 500 });
+    }
+
+    if (url.pathname === "/healthz") {
+      return Response.json({ ok: true, version: "1.0.0" });
+    }
+
+    return new Response("Not Found", { status: 404 });
+  },
+  websocket: {
+    open(ws) {
+      const log = logger.child({ clientId: ws.data.clientId });
+      log.info("ws connected");
+    },
+    message(ws, msg) {
+      const log = logger.child({ clientId: ws.data.clientId });
+      const length = typeof msg === "string" ? msg.length : msg.byteLength;
+      log.info({ length }, "ws message");
+    },
+    close(ws, code, reason) {
+      const log = logger.child({ clientId: ws.data.clientId });
+      log.info({ code, reason }, "ws closed");
+    },
+  },
+});
+
+logger.info({ port }, "server started");
+
+process.on("SIGINT", () => {
+  logger.info("shutting down");
+  server.stop(true);
+  process.exit(0);
+});

packages/server/src/logger.ts

@@ -0,0 +1,3 @@
+import pino from "pino";
+
+export const logger = pino({ level: process.env["LOG_LEVEL"] ?? "info" });

packages/server/tsconfig.json

@@ -2,6 +2,7 @@
   "extends": "../../tsconfig.base.json",
   "compilerOptions": {
     "lib": ["ES2022"],
+    "types": ["bun-types"],
     "composite": true,
     "outDir": "dist",
     "rootDir": "src"