fix(NODE-5228)!: remove unneeded fields from ConnectionPoolCreatedEve…

…nt.options (#3772)

src/cmap/connection_pool_events.ts

@@ -54,14 +54,19 @@ export abstract class ConnectionPoolMonitoringEvent {
  */
 export class ConnectionPoolCreatedEvent extends ConnectionPoolMonitoringEvent {
   /** The options used to create this connection pool */
-  options?: ConnectionPoolOptions;
+  options: Pick<
+    ConnectionPoolOptions,
+    'maxPoolSize' | 'minPoolSize' | 'maxConnecting' | 'maxIdleTimeMS' | 'waitQueueTimeoutMS'
+  >;
   /** @internal */
   name = CONNECTION_POOL_CREATED;
 
   /** @internal */
   constructor(pool: ConnectionPool) {
     super(pool);
-    this.options = pool.options;
+    const { maxConnecting, maxPoolSize, minPoolSize, maxIdleTimeMS, waitQueueTimeoutMS } =
+      pool.options;
+    this.options = { maxConnecting, maxPoolSize, minPoolSize, maxIdleTimeMS, waitQueueTimeoutMS };
   }
 }
 

test/integration/connection-monitoring-and-pooling/connection_pool.test.ts

@@ -0,0 +1,66 @@
+import { once } from 'node:events';
+
+import { expect } from 'chai';
+
+import { type ConnectionPoolCreatedEvent, type Db, type MongoClient } from '../../mongodb';
+
+describe('Connection Pool', function () {
+  let client: MongoClient;
+  let db: Db;
+  afterEach(async function () {
+    if (client) {
+      if (db) {
+        await db.dropDatabase();
+      }
+      await client.close();
+    }
+  });
+  describe('Events', function () {
+    describe('ConnectionPoolCreatedEvent', function () {
+      context('when no connection pool options are passed in', function () {
+        let pConnectionPoolCreated: Promise<ConnectionPoolCreatedEvent[]>;
+        let connectionPoolCreated: ConnectionPoolCreatedEvent;
+        beforeEach(async function () {
+          client = this.configuration.newClient({}, {});
+          pConnectionPoolCreated = once(client, 'connectionPoolCreated');
+          await client.connect();
+
+          connectionPoolCreated = (await pConnectionPoolCreated)[0];
+        });
+
+        it('the options field matches the default options', function () {
+          expect(connectionPoolCreated).to.have.deep.property('options', {
+            waitQueueTimeoutMS: 0,
+            maxIdleTimeMS: 0,
+            maxConnecting: 2,
+            minPoolSize: 0,
+            maxPoolSize: 100
+          });
+        });
+      });
+
+      context('when valid non-default connection pool options are passed in', function () {
+        let pConnectionPoolCreated: Promise<ConnectionPoolCreatedEvent[]>;
+        let connectionPoolCreated: ConnectionPoolCreatedEvent;
+        const options = {
+          waitQueueTimeoutMS: 2000,
+          maxIdleTimeMS: 1,
+          maxConnecting: 3,
+          minPoolSize: 1,
+          maxPoolSize: 101
+        };
+        beforeEach(async function () {
+          client = this.configuration.newClient({}, options);
+          pConnectionPoolCreated = once(client, 'connectionPoolCreated');
+          await client.connect();
+
+          connectionPoolCreated = (await pConnectionPoolCreated)[0];
+        });
+
+        it('the options field only contains keys and values matching the non-default options', function () {
+          expect(connectionPoolCreated).to.have.deep.property('options', options);
+        });
+      });
+    });
+  });
+});

test/types/connection_pool_events.test-d.ts

@@ -0,0 +1,20 @@
+import { once } from 'events';
+import { expectType } from 'tsd';
+
+import type { ConnectionPoolCreatedEvent } from '../mongodb';
+import { MongoClient } from '../mongodb';
+
+const client: MongoClient = new MongoClient('');
+const p = once(client, 'connectionPoolCreated');
+await client.connect();
+
+const ev: ConnectionPoolCreatedEvent = (await p)[0];
+expectType<ConnectionPoolCreatedEvent>(ev);
+
+expectType<{
+  maxPoolSize: number;
+  minPoolSize: number;
+  maxConnecting: number;
+  maxIdleTimeMS: number;
+  waitQueueTimeoutMS: number;
+}>(ev.options);

test/unit/cmap/connection_pool_events.test.ts

@@ -0,0 +1,61 @@
+import { expect } from 'chai';
+
+import { type ConnectionPool, ConnectionPoolCreatedEvent } from '../../mongodb';
+
+describe('Connection Pool Events', function () {
+  const connectionPoolMock = {
+    address: 'localhost:9000',
+    time: new Date()
+  };
+
+  describe('ConnectionPoolCreatedEvent', function () {
+    describe('constructor', function () {
+      context('when provided expected option fields', function () {
+        it(`Sets the allowed fields appropriately`, function () {
+          const options = {
+            maxIdleTimeMS: 0,
+            maxConnecting: 2,
+            minPoolSize: 0,
+            maxPoolSize: 100,
+            waitQueueTimeoutMS: 1000
+          };
+          const event = new ConnectionPoolCreatedEvent({
+            ...connectionPoolMock,
+            options
+          } as unknown as ConnectionPool);
+
+          expect(event).to.have.deep.property('options', options);
+        });
+      });
+      context('when provided unallowed fields', function () {
+        it('only stores expected fields', function () {
+          const options = {
+            maxIdleTimeMS: 0,
+            maxConnecting: 2,
+            minPoolSize: 0,
+            maxPoolSize: 100,
+            waitQueueTimeoutMS: 1000,
+            credentials: {
+              user: 'user',
+              pass: 'pass'
+            },
+            foo: 'foo',
+            hello: 'world'
+          };
+          const event = new ConnectionPoolCreatedEvent({
+            ...connectionPoolMock,
+            options
+          } as unknown as ConnectionPool);
+
+          expect(event).to.have.deep.property('options', {
+            maxIdleTimeMS: 0,
+            maxConnecting: 2,
+            minPoolSize: 0,
+            maxPoolSize: 100,
+            waitQueueTimeoutMS: 1000
+          });
+        });
+      });
+    });
+  });
+});