From 60c0b221d75fce34afc06d852fa81245fc8e5133 Mon Sep 17 00:00:00 2001
From: Neal Beeken <neal.beeken@mongodb.com>
Date: Wed, 17 Feb 2021 14:25:23 -0500
Subject: [PATCH] Move session support check into server selection for unified
 topology

---
 lib/operations/execute_operation.js | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/lib/operations/execute_operation.js b/lib/operations/execute_operation.js
index 10432e11a7..f7fb0f53be 100644
--- a/lib/operations/execute_operation.js
+++ b/lib/operations/execute_operation.js
@@ -142,6 +142,10 @@ function executeWithServerSelection(topology, operation, callback) {
       return;
     }
 
+    if (serverSelectionOptions.session && topology.hasSessionSupport()) {
+      return callback(new MongoError('Current topology does not support sessions'));
+    }
+
     const shouldRetryReads =
       topology.s.options.retryReads !== false &&
       operation.session &&