From 07a3117f0676dbe4793fcd67a05b3d0eadf5ecbc Mon Sep 17 00:00:00 2001
From: emadum <eric.adum@mongodb.com>
Date: Tue, 26 Jan 2021 21:16:24 -0500
Subject: [PATCH 1/4] fix: restore auto direct connection behavior

---
 lib/core/uri_parser.js                      | 9 +++++++++
 test/functional/sharding_connection.test.js | 7 ++++++-
 2 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/lib/core/uri_parser.js b/lib/core/uri_parser.js
index fca8032c172..57925d400eb 100644
--- a/lib/core/uri_parser.js
+++ b/lib/core/uri_parser.js
@@ -687,6 +687,15 @@ function parseConnectionString(uri, options, callback) {
     return callback(new MongoParseError('directConnection option requires exactly one host'));
   }
 
+  // NOTE: this behavior will go away in v4.0, we will always auto discover there
+  if (
+    parsedOptions.directConnection == null &&
+    hosts.length === 1 &&
+    parsedOptions.replicaSet == null
+  ) {
+    parsedOptions.directConnection = true;
+  }
+
   const result = {
     hosts: hosts,
     auth: auth.db || auth.username ? auth : null,
diff --git a/test/functional/sharding_connection.test.js b/test/functional/sharding_connection.test.js
index 8d3b5ed5d8f..c7adcd0cc90 100644
--- a/test/functional/sharding_connection.test.js
+++ b/test/functional/sharding_connection.test.js
@@ -13,7 +13,12 @@ describe('Sharding (Connection)', function() {
   it('Should use sharded topology', {
     metadata: { requires: { topology: 'sharded' } },
     test: function() {
-      const client = this.configuration.newClient({}, { useUnifiedTopology: true });
+      const client = this.configuration.newClient(
+        {},
+        // note: auto-discovery will be the default behavior in 4.0,
+        // for now we must supply directConnection: false
+        { useUnifiedTopology: true, directConnection: false }
+      );
       return withClient(client, (client, done) => {
         expect(client).to.exist;
         expect(client)

From b6e604b9b49d7404456da626f3aa76920352cb1f Mon Sep 17 00:00:00 2001
From: emadum <eric.adum@mongodb.com>
Date: Thu, 28 Jan 2021 12:56:26 -0500
Subject: [PATCH 2/4] add test

---
 test/functional/mongo_client_options.test.js | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/test/functional/mongo_client_options.test.js b/test/functional/mongo_client_options.test.js
index 50cc791abdb..b2ea9c9b519 100644
--- a/test/functional/mongo_client_options.test.js
+++ b/test/functional/mongo_client_options.test.js
@@ -168,6 +168,20 @@ describe('MongoClient Options', function() {
     }
   });
 
+  it('should directConnect when no replicaSet name is specified', {
+    metadata: { requires: { topology: 'replicaset' } },
+    test: function(done) {
+      // strip the replicaSet parameter from the url if present
+      const urlNoReplicaSet = this.configuration.url().replace(/([&?])replicaSet=.+?[&$]/, '$1');
+      const client = this.configuration.newClient(urlNoReplicaSet);
+      client.connect(err => {
+        expect(err).to.not.exist;
+        expect(client.s.options.directConnection).to.be.true;
+        client.close(done);
+      });
+    }
+  });
+
   /**
    * @ignore
    */

From 04442f605c2796028cb463b9d581f59766665efd Mon Sep 17 00:00:00 2001
From: emadum <eric.adum@mongodb.com>
Date: Thu, 28 Jan 2021 18:26:01 -0500
Subject: [PATCH 3/4] fix test on evergreen

---
 test/functional/mongo_client_options.test.js | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/test/functional/mongo_client_options.test.js b/test/functional/mongo_client_options.test.js
index b2ea9c9b519..d905c8c606f 100644
--- a/test/functional/mongo_client_options.test.js
+++ b/test/functional/mongo_client_options.test.js
@@ -171,8 +171,12 @@ describe('MongoClient Options', function() {
   it('should directConnect when no replicaSet name is specified', {
     metadata: { requires: { topology: 'replicaset' } },
     test: function(done) {
-      // strip the replicaSet parameter from the url if present
-      const urlNoReplicaSet = this.configuration.url().replace(/([&?])replicaSet=.+?[&$]/, '$1');
+      const urlNoReplicaSet = this.configuration
+        .url()
+        // strip the replicaSet parameter from the url if present
+        .replace(/([&?])replicaSet=.+?[&$]/, '$1')
+        // reduce down to a single host if multiple are provided
+        .replace(new RegExp('(^mongodb://[^,]+)[^/]+'), '$1');
       const client = this.configuration.newClient(urlNoReplicaSet);
       client.connect(err => {
         expect(err).to.not.exist;

From faeeb5a69b74ad5b7d74252d61c4f273e165650a Mon Sep 17 00:00:00 2001
From: emadum <eric.adum@mongodb.com>
Date: Thu, 28 Jan 2021 18:26:17 -0500
Subject: [PATCH 4/4] remove finally for old node versions

---
 test/functional/bulk.test.js | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/test/functional/bulk.test.js b/test/functional/bulk.test.js
index d42655c6b3a..ced20b1f36d 100644
--- a/test/functional/bulk.test.js
+++ b/test/functional/bulk.test.js
@@ -1687,9 +1687,10 @@ describe('Bulk', function() {
           );
         }
       })
-      .finally(() => {
-        return client.close();
-      });
+      .then(
+        () => client.close(),
+        () => client.close()
+      );
   });
 
   it('should respect toBSON conversion when checking for atomic operators', function() {
@@ -1721,8 +1722,9 @@ describe('Bulk', function() {
           expect.fail(); // shouldn't throw any error
         }
       })
-      .finally(() => {
-        return client.close();
-      });
+      .then(
+        () => client.close(),
+        () => client.close()
+      );
   });
 });