From c1fbd54eaadf82c1e5e4826f56c4096598467641 Mon Sep 17 00:00:00 2001
From: Sergey Zelenov <sergey.zelenov@mongodb.com>
Date: Fri, 27 Feb 2026 11:02:38 +0100
Subject: [PATCH 1/2] test(NODE-7451): sync spec tests for server selection

---
 .../read/SecondaryPreferred_empty_tags.json   | 41 +++++++++++++++++++
 .../read/SecondaryPreferred_empty_tags.yml    | 26 ++++++++++++
 .../assorted/server_selection.spec.test.ts    |  2 +-
 3 files changed, 68 insertions(+), 1 deletion(-)
 create mode 100644 test/spec/server-selection/server_selection/ReplicaSetWithPrimary/read/SecondaryPreferred_empty_tags.json
 create mode 100644 test/spec/server-selection/server_selection/ReplicaSetWithPrimary/read/SecondaryPreferred_empty_tags.yml

diff --git a/test/spec/server-selection/server_selection/ReplicaSetWithPrimary/read/SecondaryPreferred_empty_tags.json b/test/spec/server-selection/server_selection/ReplicaSetWithPrimary/read/SecondaryPreferred_empty_tags.json
new file mode 100644
index 00000000000..5cc088df4cb
--- /dev/null
+++ b/test/spec/server-selection/server_selection/ReplicaSetWithPrimary/read/SecondaryPreferred_empty_tags.json
@@ -0,0 +1,41 @@
+{
+  "topology_description": {
+    "type": "ReplicaSetWithPrimary",
+    "servers": [
+      {
+        "address": "a:27017",
+        "avg_rtt_ms": 5,
+        "type": "RSPrimary"
+      },
+      {
+        "address": "b:27017",
+        "avg_rtt_ms": 5,
+        "type": "RSSecondary"
+      }
+    ]
+  },
+  "operation": "read",
+  "read_preference": {
+    "mode": "SecondaryPreferred",
+    "tag_sets": [
+      {
+        "data_center": "nyc"
+      },
+      {}
+    ]
+  },
+  "suitable_servers": [
+    {
+      "address": "b:27017",
+      "avg_rtt_ms": 5,
+      "type": "RSSecondary"
+    }
+  ],
+  "in_latency_window": [
+    {
+      "address": "b:27017",
+      "avg_rtt_ms": 5,
+      "type": "RSSecondary"
+    }
+  ]
+}
\ No newline at end of file
diff --git a/test/spec/server-selection/server_selection/ReplicaSetWithPrimary/read/SecondaryPreferred_empty_tags.yml b/test/spec/server-selection/server_selection/ReplicaSetWithPrimary/read/SecondaryPreferred_empty_tags.yml
new file mode 100644
index 00000000000..72f2bd53ae7
--- /dev/null
+++ b/test/spec/server-selection/server_selection/ReplicaSetWithPrimary/read/SecondaryPreferred_empty_tags.yml
@@ -0,0 +1,26 @@
+# Attempt to select the secondary using an empty tag set. Expect empty tag set to match.
+# This is a regression test for RUST-2363.
+---
+topology_description:
+  type: ReplicaSetWithPrimary
+  servers:
+    - &1
+      address: a:27017
+      avg_rtt_ms: 5
+      type: RSPrimary
+      # No "tags".
+    - &2
+      address: b:27017
+      avg_rtt_ms: 5
+      type: RSSecondary
+      # No "tags"
+operation: read
+read_preference:
+  mode: SecondaryPreferred
+  tag_sets:
+    - data_center: nyc # Does not match.
+    - {} # Empty tag set.
+suitable_servers:
+  - *2
+in_latency_window:
+  - *2
\ No newline at end of file
diff --git a/test/unit/assorted/server_selection.spec.test.ts b/test/unit/assorted/server_selection.spec.test.ts
index 44707aa7580..098848df05e 100644
--- a/test/unit/assorted/server_selection.spec.test.ts
+++ b/test/unit/assorted/server_selection.spec.test.ts
@@ -11,7 +11,7 @@ import {
   runServerSelectionLogicTest
 } from './server_selection_logic_spec_utils';
 
-describe('Server Selection Logic (spec)', function () {
+describe.only('Server Selection Logic (spec)', function () {
   beforeEach(function () {
     if (this.currentTest.title.match(/Possible/)) {
       this.currentTest.skipReason = 'Nodejs driver does not support PossiblePrimary';

From e619739297094575f4a47bb7aa2cd3e8ec4322a7 Mon Sep 17 00:00:00 2001
From: Sergey Zelenov <sergey.zelenov@mongodb.com>
Date: Fri, 27 Feb 2026 22:47:18 +0100
Subject: [PATCH 2/2] run all tests

---
 test/unit/assorted/server_selection.spec.test.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/test/unit/assorted/server_selection.spec.test.ts b/test/unit/assorted/server_selection.spec.test.ts
index 098848df05e..44707aa7580 100644
--- a/test/unit/assorted/server_selection.spec.test.ts
+++ b/test/unit/assorted/server_selection.spec.test.ts
@@ -11,7 +11,7 @@ import {
   runServerSelectionLogicTest
 } from './server_selection_logic_spec_utils';
 
-describe.only('Server Selection Logic (spec)', function () {
+describe('Server Selection Logic (spec)', function () {
   beforeEach(function () {
     if (this.currentTest.title.match(/Possible/)) {
       this.currentTest.skipReason = 'Nodejs driver does not support PossiblePrimary';