BREAKING CHANGE: remove connection noListener option

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
  */

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
  */
@@ -107,21 +106,15 @@ 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();
   }
 
   newConn.name = name;
 
-  // push onto the otherDbs stack, this is used when state changes and when heartbeat is received
-  if (options.noListener !== true) {
-    this.otherDbs.push(newConn);
-  }
+  // push onto the otherDbs stack, this is used when state changes
+  this.otherDbs.push(newConn);
   newConn.otherDbs.push(this);
 
   // push onto the relatedDbs cache, this is used when state changes

test/types/connection.test.ts

@@ -75,7 +75,6 @@ expectType<Promise<ConnectionSyncIndexesResult>>(conn.syncIndexes({ continueOnEr
 
 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[]>>(

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;