From 8878301c7f1736039efc59a1dff96a1f882a68f5 Mon Sep 17 00:00:00 2001
From: Joseph Doherty <dohejw01@gmail.com>
Date: Mon, 23 Feb 2026 01:05:10 -0500
Subject: [PATCH] test: add file logging and rotation tests

---
 tests/NATS.Server.Tests/LoggingTests.cs       | 60 +++++++++++++++++++
 .../NATS.Server.Tests.csproj                  |  1 +
 2 files changed, 61 insertions(+)
 create mode 100644 tests/NATS.Server.Tests/LoggingTests.cs

diff --git a/tests/NATS.Server.Tests/LoggingTests.cs b/tests/NATS.Server.Tests/LoggingTests.cs
new file mode 100644
index 0000000..d1daf6d
--- /dev/null
+++ b/tests/NATS.Server.Tests/LoggingTests.cs
@@ -0,0 +1,60 @@
+using Serilog;
+
+namespace NATS.Server.Tests;
+
+public class LoggingTests : IDisposable
+{
+    private readonly string _logDir;
+
+    public LoggingTests()
+    {
+        _logDir = Path.Combine(Path.GetTempPath(), $"nats-log-test-{Guid.NewGuid():N}");
+        Directory.CreateDirectory(_logDir);
+    }
+
+    public void Dispose()
+    {
+        try { Directory.Delete(_logDir, true); } catch { }
+    }
+
+    [Fact]
+    public void File_sink_creates_log_file()
+    {
+        var logPath = Path.Combine(_logDir, "test.log");
+
+        using var logger = new LoggerConfiguration()
+            .WriteTo.File(logPath)
+            .CreateLogger();
+
+        logger.Information("Hello from test");
+        logger.Dispose();
+
+        File.Exists(logPath).ShouldBeTrue();
+        var content = File.ReadAllText(logPath);
+        content.ShouldContain("Hello from test");
+    }
+
+    [Fact]
+    public void File_sink_rotates_on_size_limit()
+    {
+        var logPath = Path.Combine(_logDir, "rotate.log");
+
+        using var logger = new LoggerConfiguration()
+            .WriteTo.File(
+                logPath,
+                fileSizeLimitBytes: 200,
+                rollOnFileSizeLimit: true,
+                retainedFileCountLimit: 3)
+            .CreateLogger();
+
+        // Write enough to trigger rotation
+        for (int i = 0; i < 50; i++)
+            logger.Information("Log message number {Number} with some padding text", i);
+
+        logger.Dispose();
+
+        // Should have created rotated files
+        var logFiles = Directory.GetFiles(_logDir, "rotate*.log");
+        logFiles.Length.ShouldBeGreaterThan(1);
+    }
+}
diff --git a/tests/NATS.Server.Tests/NATS.Server.Tests.csproj b/tests/NATS.Server.Tests/NATS.Server.Tests.csproj
index 611a86f..67f3fe4 100644
--- a/tests/NATS.Server.Tests/NATS.Server.Tests.csproj
+++ b/tests/NATS.Server.Tests/NATS.Server.Tests.csproj
@@ -13,6 +13,7 @@
     <PackageReference Include="xunit" />
     <PackageReference Include="xunit.runner.visualstudio" />
     <PackageReference Include="NATS.NKeys" />
+    <PackageReference Include="Serilog.Sinks.File" />
   </ItemGroup>
 
   <ItemGroup>