Add connection logging for debugging disconnects

Logs all connect/disconnect/close events with player IDs, room codes,
and close codes. Logs relay packets (first 20 + every 100th). Logs
ping/pong keepalive terminations.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/index.js

@@ -5,6 +5,11 @@ const { RelayHandler } = require('./relay');
 
 const PORT = process.env.PORT || 3000;
 
+function log(tag, msg) {
+  const ts = new Date().toISOString().slice(11, 23);
+  console.log(`[${ts}] [${tag}] ${msg}`);
+}
+
 const server = http.createServer((req, res) => {
   if (req.url === '/health') {
     res.writeHead(200, { 'Content-Type': 'application/json' });
@@ -38,6 +43,8 @@ wss.on('connection', (ws) => {
   ws.playerName = null;
   ws.isRelaying = false;
 
+  log('CONN', `New WebSocket connection. Total clients: ${wss.clients.size}`);
+
   ws.on('pong', () => { ws.isAlive = true; });
 
   ws.on('message', (data, isBinary) => {
@@ -48,34 +55,50 @@ wss.on('connection', (ws) => {
       }
 
       const msg = JSON.parse(data.toString());
+      log('MSG', `player=${ws.playerId} room=${ws.roomCode} type=${msg.type}`);
       handleMessage(ws, msg);
     } catch (e) {
+      log('ERR', `Bad message from player=${ws.playerId}: ${e.message}`);
       sendError(ws, 'Invalid message format');
     }
   });
 
-  ws.on('close', () => {
+  ws.on('close', (code, reason) => {
+    log('CLOSE', `player=${ws.playerId} room=${ws.roomCode} name=${ws.playerName} code=${code} reason=${reason || 'none'}`);
     if (ws.roomCode) {
       const room = roomManager.getRoom(ws.roomCode);
       if (room) {
         room.removePlayer(ws.playerId);
         if (room.isEmpty()) {
+          log('ROOM', `Room ${ws.roomCode} deleted (empty)`);
           roomManager.deleteRoom(ws.roomCode);
         } else {
+          log('ROOM', `Room ${ws.roomCode} now has ${room.getPlayerCount()} players`);
           broadcastLobbyState(room);
         }
       }
     }
   });
+
+  ws.on('error', (err) => {
+    log('WS_ERR', `player=${ws.playerId} room=${ws.roomCode}: ${err.message}`);
+  });
 });
 
 // Ping/pong keepalive
 setInterval(() => {
+  let terminated = 0;
   wss.clients.forEach((ws) => {
-    if (!ws.isAlive) { ws.terminate(); return; }
+    if (!ws.isAlive) {
+      log('PING', `Terminating dead connection: player=${ws.playerId} room=${ws.roomCode}`);
+      ws.terminate();
+      terminated++;
+      return;
+    }
     ws.isAlive = false;
     ws.ping();
   });
+  if (terminated > 0) log('PING', `Terminated ${terminated} dead connections`);
 }, 30000);
 
 // Room cleanup (stale rooms older than 30 min)

src/relay.js

 const { WebSocket } = require('ws');
 
+function log(tag, msg) {
+  const ts = new Date().toISOString().slice(11, 23);
+  console.log(`[${ts}] [${tag}] ${msg}`);
+}
+
 class RelayHandler {
   constructor(roomManager) {
     this.roomManager = roomManager;
+    this._packetCount = 0;
   }
 
   handlePacket(ws, data) {
-    if (!ws.roomCode) return;
+    if (!ws.roomCode) {
+      log('RELAY', `Binary from player=${ws.playerId} but no room!`);
+      return;
+    }
 
     const room = this.roomManager.getRoom(ws.roomCode);
-    if (!room || room.state !== 'playing') return;
+    if (!room || room.state !== 'playing') {
+      log('RELAY', `Binary from player=${ws.playerId} but room state=${room?.state || 'null'}`);
+      return;
+    }
 
     const buffer = Buffer.isBuffer(data) ? data : Buffer.from(data);
 
-    // Packet format:
-    // First byte = target:
-    //   0x00 = broadcast to all except sender
-    //   0x01 = to host only
-    //   0xFF = to all clients (from host)
-    //   0x02-0xFE = to specific player ID
-    // Remaining bytes = FishNet payload
-
     if (buffer.length < 2) return;
 
     const target = buffer[0];
@@ -31,6 +35,11 @@ class RelayHandler {
     relayedPacket.writeUInt16LE(ws.playerId, 0);
     payload.copy(relayedPacket, 2);
 
+    this._packetCount++;
+    if (this._packetCount <= 20 || this._packetCount % 100 === 0) {
+      log('RELAY', `#${this._packetCount} from=${ws.playerId} target=0x${target.toString(16)} len=${buffer.length} room=${ws.roomCode}`);
+    }
+
     switch (target) {
       case 0x00: // Broadcast to all except sender
         this.broadcastExcept(room, ws.playerId, relayedPacket);