test: fix integration flakiness from shared-etcd cross-contamination

dotnet-etcd.Tests/Integration/WatchResilienceTests.cs

@@ -16,9 +16,10 @@ public class WatchResilienceTests : IDisposable
         private readonly EtcdClient _client;
         private readonly string _testKeyPrefix = "watch-resilience-";
 
-        // Use etcd1 (port 2379) as per standard test env
-        private const string EtcdUrl = "http://localhost:2379";
-        private const string ContainerName = "etcd1";
+        // Dedicated single-node etcd (port 2409) so pausing/restarting the server here never
+        // disrupts the shared etcd1 cluster used by the other integration tests.
+        private const string EtcdUrl = "http://localhost:2409";
+        private const string ContainerName = "etcd-resilience";
 
         public WatchResilienceTests()
         {

dotnet-etcd.Tests/docker-compose.yml

@@ -95,6 +95,23 @@ services:
     networks:
       - etcd-net
 
+  # Dedicated single-node etcd for WatchResilienceTests, which pause/restart their server.
+  # Isolated on its own port so that disruption never affects the shared etcd1 cluster tests.
+  etcd-resilience:
+    image: quay.io/coreos/etcd:v3.5.21
+    container_name: etcd-resilience
+    ports:
+      - "2409:2379"
+    command:
+      - /usr/local/bin/etcd
+      - --name=etcd-resilience
+      - --data-dir=/etcd-data
+      - --listen-client-urls=http://0.0.0.0:2379
+      - --advertise-client-urls=http://localhost:2409
+    restart: always
+    networks:
+      - etcd-net
+
 networks:
   etcd-net:
     driver: bridge

dotnet-etcd.Tests/dotnet-etcd.Tests.csproj

@@ -41,6 +41,10 @@
         <Content Include="certs\**">
             <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
         </Content>
+        <!-- Serialize test collections: the integration tests share a single etcd instance and
+             mutate global state (auth enable/disable, server restart), so running collections in
+             parallel causes cross-test interference and flakiness. -->
+        <None Include="xunit.runner.json" CopyToOutputDirectory="PreserveNewest" />
     </ItemGroup>
 
 </Project>

dotnet-etcd.Tests/xunit.runner.json

@@ -0,0 +1,4 @@
+{
+  "$schema": "https://xunit.net/schema/current/xunit.runner.schema.json",
+  "parallelizeTestCollections": false
+}