Make session cleanup atomic in leave()

src/index.ts

@@ -1,10 +1,5 @@
 import { decode } from "./protocol";
-import {
-  type Client,
-  getOrCreateSession,
-  getSession,
-  removeSession,
-} from "./session";
+import { type Client, getOrCreateSession, getSession } from "./session";
 
 const PORT = Number(process.env.PORT) || 4040;
 
@@ -66,7 +61,6 @@ Bun.serve({
           if (ws.data.room) {
             const session = getSession(ws.data.room);
             session?.leave(client);
-            removeSession(ws.data.room);
             ws.data.room = null;
           }
           break;
@@ -84,7 +78,6 @@ Bun.serve({
       if (ws.data.room && ws.data.client) {
         const session = getSession(ws.data.room);
         session?.leave(ws.data.client);
-        removeSession(ws.data.room);
       }
       console.debug("client disconnected");
     },

src/session.ts

@@ -31,6 +31,10 @@ export class Session {
   leave(client: Client) {
     this.clients.delete(client);
     this.broadcastPeerCount();
+    if (this.isEmpty()) {
+      sessions.delete(this.name);
+      console.debug(`session removed: ${this.name}`);
+    }
   }
 
   isEmpty(): boolean {