fix: socket timeout for handshake should be connectTimeoutMS

Author: mbroadst

lib/core/connection/connect.js

@@ -111,8 +111,15 @@ function performInitialHandshake(conn, options, _callback) {
     getSaslSupportedMechs(options)
   );
 
+  const handshakeOptions = Object.assign({}, options);
+
+  // The handshake technically is a monitoring check, so its socket timeout should be connectTimeoutMS
+  if (options.connectTimeoutMS || options.connectionTimeout) {
+    handshakeOptions.socketTimeout = options.connectTimeoutMS || options.connectionTimeout;
+  }
+
   const start = new Date().getTime();
-  runCommand(conn, 'admin.$cmd', handshakeDoc, options, (err, ismaster) => {
+  runCommand(conn, 'admin.$cmd', handshakeDoc, handshakeOptions, (err, ismaster) => {
     if (err) {
       callback(err);
       return;
@@ -235,7 +242,11 @@ function makeConnection(family, options, cancellationToken, _callback) {
     typeof options.keepAliveInitialDelay === 'number' ? options.keepAliveInitialDelay : 300000;
   const noDelay = typeof options.noDelay === 'boolean' ? options.noDelay : true;
   const connectionTimeout =
-    typeof options.connectionTimeout === 'number' ? options.connectionTimeout : 30000;
+    typeof options.connectionTimeout === 'number'
+      ? options.connectionTimeout
+      : typeof options.connectTimeoutMS === 'number'
+      ? options.connectTimeoutMS
+      : 30000;
   const socketTimeout = typeof options.socketTimeout === 'number' ? options.socketTimeout : 360000;
   const rejectUnauthorized =
     typeof options.rejectUnauthorized === 'boolean' ? options.rejectUnauthorized : true;

lib/core/sdam/monitor.js

@@ -70,6 +70,7 @@ class Monitor extends EventEmitter {
           connectionType: Connection
         },
         server.s.options,
+        this.options,
 
         // force BSON serialization options
         {