From a3e4c880ae2f6dc5fb1ce1b3ef1b0d8bd5e969a3 Mon Sep 17 00:00:00 2001
From: Valeri Karpov <val@karpov.io>
Date: Mon, 22 Sep 2025 11:15:34 -0400
Subject: [PATCH] Remove noListener option from useDb

---
 lib/connection.js                             |  1 -
 lib/drivers/node-mongodb-native/connection.js | 11 ++---------
 test/types/connection.test.ts                 |  1 -
 types/connection.d.ts                         |  2 +-
 4 files changed, 3 insertions(+), 12 deletions(-)

diff --git a/lib/connection.js b/lib/connection.js
index 5a8b2c8ca55..973f7caa114 100644
--- a/lib/connection.js
+++ b/lib/connection.js
@@ -1798,7 +1798,6 @@ Connection.prototype.syncIndexes = async function syncIndexes(options = {}) {
  * @param {String} name The database name
  * @param {Object} [options]
  * @param {Boolean} [options.useCache=false] If true, cache results so calling `useDb()` multiple times with the same name only creates 1 connection object.
- * @param {Boolean} [options.noListener=false] If true, the connection object will not make the db listen to events on the original connection. See [issue #9961](https://github.com/Automattic/mongoose/issues/9961).
  * @return {Connection} New Connection Object
  * @api public
  */
diff --git a/lib/drivers/node-mongodb-native/connection.js b/lib/drivers/node-mongodb-native/connection.js
index 9e9f8952f6f..e2fc506ed94 100644
--- a/lib/drivers/node-mongodb-native/connection.js
+++ b/lib/drivers/node-mongodb-native/connection.js
@@ -55,7 +55,6 @@ Object.setPrototypeOf(NativeConnection.prototype, MongooseConnection.prototype);
  * @param {String} name The database name
  * @param {Object} [options]
  * @param {Boolean} [options.useCache=false] If true, cache results so calling `useDb()` multiple times with the same name only creates 1 connection object.
- * @param {Boolean} [options.noListener=false] If true, the new connection object won't listen to any events on the base connection. This is better for memory usage in cases where you're calling `useDb()` for every request.
  * @return {Connection} New Connection Object
  * @api public
  */
@@ -107,11 +106,7 @@ NativeConnection.prototype.useDb = function(name, options) {
 
   function wireup() {
     newConn.client = _this.client;
-    const _opts = {};
-    if (options.hasOwnProperty('noListener')) {
-      _opts.noListener = options.noListener;
-    }
-    newConn.db = _this.client.db(name, _opts);
+    newConn.db = _this.client.db(name);
     newConn._lastHeartbeatAt = _this._lastHeartbeatAt;
     newConn.onOpen();
   }
@@ -119,9 +114,7 @@ NativeConnection.prototype.useDb = function(name, options) {
   newConn.name = name;
 
   // push onto the otherDbs stack, this is used when state changes
-  if (options.noListener !== true) {
-    this.otherDbs.push(newConn);
-  }
+  this.otherDbs.push(newConn);
   newConn.otherDbs.push(this);
 
   // push onto the relatedDbs cache, this is used when state changes
diff --git a/test/types/connection.test.ts b/test/types/connection.test.ts
index 77ca1787685..f69f2b0065a 100644
--- a/test/types/connection.test.ts
+++ b/test/types/connection.test.ts
@@ -76,7 +76,6 @@ expectType<Promise<ConnectionSyncIndexesResult>>(conn.syncIndexes({ background:
 
 expectType<Connection>(conn.useDb('test'));
 expectType<Connection>(conn.useDb('test', {}));
-expectType<Connection>(conn.useDb('test', { noListener: true }));
 expectType<Connection>(conn.useDb('test', { useCache: true }));
 
 expectType<Promise<string[]>>(
diff --git a/types/connection.d.ts b/types/connection.d.ts
index d7ee4638edd..76b36d17e6f 100644
--- a/types/connection.d.ts
+++ b/types/connection.d.ts
@@ -273,7 +273,7 @@ declare module 'mongoose' {
     transaction<ReturnType = unknown>(fn: (session: mongodb.ClientSession) => Promise<ReturnType>, options?: mongodb.TransactionOptions): Promise<ReturnType>;
 
     /** Switches to a different database using the same connection pool. */
-    useDb(name: string, options?: { useCache?: boolean, noListener?: boolean }): Connection;
+    useDb(name: string, options?: { useCache?: boolean }): Connection;
 
     /** The username specified in the URI */
     readonly user: string;