From ca527f41783c016a5c992a7e4a0c751870dbdfe5 Mon Sep 17 00:00:00 2001
From: Valeri Karpov <val@karpov.io>
Date: Thu, 28 Nov 2019 08:36:12 -0500
Subject: [PATCH] fix: use serverDescriptionChanged event to distinguish
 between timeout vs disconnected re: #8383

---
 lib/connection.js       | 17 +++++++++--------
 test/connection.test.js |  1 -
 2 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/lib/connection.js b/lib/connection.js
index ed1d5b56dd2..ff75f118786 100644
--- a/lib/connection.js
+++ b/lib/connection.js
@@ -677,15 +677,16 @@ Connection.prototype.openUri = function(uri, options, callback) {
           server.s.pool.on('reconnect', () => {
             _handleReconnect();
           });
-          server.s.pool.on('timeout', () => {
-            _this.emit('timeout');
-          });
-          client.on('serverClosed', () => {
-            _this.readyState = STATES.disconnected;
-          });
-          server.s.pool.on('drain', err => {
-            if (err && err.name === 'MongoNetworkError' && err.message.endsWith('timed out')) {
+          client.on('serverDescriptionChanged', ev => {
+            const newDescription = ev.newDescription;
+            if (newDescription.type === 'Standalone') {
+              _handleReconnect();
+            } else if (newDescription.error != null &&
+              newDescription.error.name === 'MongoNetworkError' &&
+              newDescription.error.message.endsWith('timed out')) {
               _this.emit('timeout');
+            } else {
+              _this.readyState = STATES.disconnected;
             }
           });
         } else if (type.startsWith('ReplicaSet')) {
diff --git a/test/connection.test.js b/test/connection.test.js
index 7a3ca8a0d67..170d0782380 100644
--- a/test/connection.test.js
+++ b/test/connection.test.js
@@ -341,7 +341,6 @@ describe('connections:', function() {
         });
 
         conn.on('disconnected', function() {
-          console.log('Disconnected', new Error().stack);
           ++numDisconnected;
         });