fix(nestjs): treat WsException as expected error

packages/nestjs/src/helpers.ts

@@ -2,6 +2,8 @@
  * Determines if the exception is an expected NestJS control flow error.
  * - HttpException have getStatus and getResponse methods: https://github.com/nestjs/nest/blob/master/packages/microservices/exceptions/rpc-exception.ts
  * - RpcException have getError and initMessage methods: https://github.com/nestjs/nest/blob/master/packages/common/exceptions/http.exception.ts
+ * - WsException has getError and initMessage in current Nest versions, but we also accept a WsException-shaped fallback
+ *   identified by constructor name to avoid reporting control-flow websocket exceptions.
  *
  * We cannot use `instanceof HttpException` here because this file is imported
  * from the main entry point (via decorators.ts), and importing @nestjs/common at that
@@ -25,10 +27,15 @@ export function isExpectedError(exception: unknown): boolean {
     return true;
   }
 
-  // RpcException
+  // RpcException / WsException (current Nest versions)
   if (typeof ex.getError === 'function' && typeof ex.initMessage === 'function') {
     return true;
   }
 
+  // WsException fallback (older/custom variants may not expose initMessage)
+  if (typeof ex.getError === 'function' && ex.constructor?.name === 'WsException') {
+    return true;
+  }
+
   return false;
 }

packages/nestjs/test/helpers.test.ts

@@ -15,6 +15,14 @@ describe('isExpectedError', () => {
     expect(isExpectedError(rpcLike)).toBe(true);
   });
 
+  it('should return true for WsException-like objects without initMessage', () => {
+    const wsLike = {
+      getError: () => 'some error',
+      constructor: { name: 'WsException' },
+    };
+    expect(isExpectedError(wsLike)).toBe(true);
+  });
+
   it('should return false for plain Error', () => {
     expect(isExpectedError(new Error('test'))).toBe(false);
   });