refactor(server): folder structure (#5573)

packages/backend/server/src/fundamentals/websocket/index.ts

@@ -0,0 +1 @@
+export { RedisIoAdapter } from './redis-adapter';

packages/backend/server/src/fundamentals/websocket/redis-adapter.ts

@@ -0,0 +1,27 @@
+import { IoAdapter } from '@nestjs/platform-socket.io';
+import { createAdapter } from '@socket.io/redis-adapter';
+import { Redis } from 'ioredis';
+import { ServerOptions } from 'socket.io';
+
+export class RedisIoAdapter extends IoAdapter {
+  private adapterConstructor: ReturnType<typeof createAdapter> | undefined;
+
+  async connectToRedis(redis: Redis): Promise<void> {
+    const pubClient = redis;
+    pubClient.on('error', err => {
+      console.error(err);
+    });
+    const subClient = pubClient.duplicate();
+    subClient.on('error', err => {
+      console.error(err);
+    });
+
+    this.adapterConstructor = createAdapter(pubClient, subClient);
+  }
+
+  override createIOServer(port: number, options?: ServerOptions): any {
+    const server = super.createIOServer(port, options);
+    server.adapter(this.adapterConstructor);
+    return server;
+  }
+}