feat(NODE-5754): allow auto select family options

src/cmap/connect.ts

@@ -269,6 +269,8 @@ export const LEGAL_TLS_SOCKET_OPTIONS = [
 
 /** @public */
 export const LEGAL_TCP_SOCKET_OPTIONS = [
+  'autoSelectFamily',
+  'autoSelectFamilyAttemptTimeout',
   'family',
   'hints',
   'localAddress',
@@ -287,6 +289,10 @@ function parseConnectOptions(options: ConnectionOptions): SocketConnectOpts {
     }
   }
 
+  if (!('autoSelectFamily' in result)) {
+    result.autoSelectFamily = true;
+  }
+
   if (typeof hostAddress.socketPath === 'string') {
     result.path = hostAddress.socketPath;
     return result as net.IpcNetConnectOpts;

src/connection_string.ts

@@ -740,6 +740,12 @@ export const OPTIONS = {
   autoEncryption: {
     type: 'record'
   },
+  autoSelectFamily: {
+    type: 'boolean'
+  },
+  autoSelectFamilyAttemptTimeout: {
+    type: 'uint'
+  },
   bsonRegExp: {
     type: 'boolean'
   },

src/mongo_client.ts

@@ -104,7 +104,7 @@ export type SupportedTLSSocketOptions = Pick<
 
 /** @public */
 export type SupportedSocketOptions = Pick<
-  TcpNetConnectOpts,
+  TcpNetConnectOpts & { autoSelectFamily?: boolean; autoSelectFamilyAttemptTimeout?: number },
   (typeof LEGAL_TCP_SOCKET_OPTIONS)[number]
 >;
 

test/integration/node-specific/mongo_client.test.ts

@@ -1,5 +1,6 @@
 import { expect } from 'chai';
 import { once } from 'events';
+import * as net from 'net';
 import * as sinon from 'sinon';
 
 import {
@@ -721,4 +722,56 @@ describe('class MongoClient', function () {
       });
     });
   });
+
+  context('when connecting', function () {
+    let netSpy;
+
+    beforeEach(function () {
+      netSpy = sinon.spy(net, 'createConnection');
+    });
+
+    afterEach(function () {
+      sinon.restore();
+    });
+
+    context('when auto select options are provided', function () {
+      beforeEach(function () {
+        client = this.configuration.newClient({
+          autoSelectFamily: false,
+          autoSelectFamilyAttemptTimeout: 100
+        });
+      });
+
+      it('sets the provided options', {
+        metadata: { requires: { topology: ['single'] } },
+        test: async function () {
+          await client.connect();
+          expect(netSpy).to.have.been.calledWith({
+            autoSelectFamily: false,
+            autoSelectFamilyAttemptTimeout: 100,
+            host: 'localhost',
+            port: 27017
+          });
+        }
+      });
+    });
+
+    context('when auto select options are not provided', function () {
+      beforeEach(function () {
+        client = this.configuration.newClient();
+      });
+
+      it('sets the default options', {
+        metadata: { requires: { topology: ['single'] } },
+        test: async function () {
+          await client.connect();
+          expect(netSpy).to.have.been.calledWith({
+            autoSelectFamily: true,
+            host: 'localhost',
+            port: 27017
+          });
+        }
+      });
+    });
+  });
 });

test/manual/mocharc.json

@@ -1,5 +1,8 @@
 {
-  "require": "ts-node/register",
+  "require": [
+    "ts-node/register",
+    "test/tools/runner/chai_addons.ts"
+  ],
   "reporter": "test/tools/reporter/mongodb_reporter.js",
   "failZero": true,
   "color": true,

test/manual/tls_support.test.ts

@@ -1,7 +1,9 @@
 import * as process from 'node:process';
+import * as tls from 'node:tls';
 
 import { expect } from 'chai';
 import { promises as fs } from 'fs';
+import * as sinon from 'sinon';
 
 import {
   LEGACY_HELLO_COMMAND,
@@ -61,6 +63,63 @@ describe('TLS Support', function () {
     });
 
     context('when tls filepaths have length > 0', () => {
+      context('when auto family options are not set', function () {
+        let tlsSpy;
+
+        afterEach(function () {
+          sinon.restore();
+        });
+
+        beforeEach(function () {
+          client = new MongoClient(CONNECTION_STRING, tlsSettings);
+          tlsSpy = sinon.spy(tls, 'connect');
+        });
+
+        it('sets the default options', async function () {
+          await client.connect();
+          expect(tlsSpy).to.have.been.calledWith({
+            autoSelectFamily: true,
+            host: 'localhost',
+            port: 27017,
+            servername: 'localhost',
+            ca: sinon.match.defined,
+            cert: sinon.match.defined,
+            key: sinon.match.defined
+          });
+        });
+      });
+
+      context('when auto family options are set', function () {
+        let tlsSpy;
+
+        afterEach(function () {
+          sinon.restore();
+        });
+
+        beforeEach(function () {
+          client = new MongoClient(CONNECTION_STRING, {
+            ...tlsSettings,
+            autoSelectFamily: false,
+            autoSelectFamilyAttemptTimeout: 100
+          });
+          tlsSpy = sinon.spy(tls, 'connect');
+        });
+
+        it('sets the provided options', async function () {
+          await client.connect();
+          expect(tlsSpy).to.have.been.calledWith({
+            autoSelectFamily: false,
+            autoSelectFamilyAttemptTimeout: 100,
+            host: 'localhost',
+            port: 27017,
+            servername: 'localhost',
+            ca: sinon.match.defined,
+            cert: sinon.match.defined,
+            key: sinon.match.defined
+          });
+        });
+      });
+
       context('when connection will succeed', () => {
         beforeEach(async () => {
           client = new MongoClient(CONNECTION_STRING, tlsSettings);