From 85546c48c5b3fce77dcc83c6b71cd849e6504124 Mon Sep 17 00:00:00 2001
From: "github-actions[bot]"
 <41898282+github-actions[bot]@users.noreply.github.com>
Date: Wed, 29 Apr 2026 00:26:18 +0000
Subject: [PATCH] Add unit tests for LoggerFactoryProxy

Tests verify:
- CreateLogger before SetLoggerFactory is called throws InvalidOperationException
- SetLoggerFactory with null throws ArgumentNullException
- CreateLogger after initialization delegates to the inner factory

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
---
 .../Logging/LoggerFactoryProxyTests.cs        | 44 +++++++++++++++++++
 1 file changed, 44 insertions(+)
 create mode 100644 test/UnitTests/Microsoft.Testing.Platform.UnitTests/Logging/LoggerFactoryProxyTests.cs

diff --git a/test/UnitTests/Microsoft.Testing.Platform.UnitTests/Logging/LoggerFactoryProxyTests.cs b/test/UnitTests/Microsoft.Testing.Platform.UnitTests/Logging/LoggerFactoryProxyTests.cs
new file mode 100644
index 0000000000..43abce1894
--- /dev/null
+++ b/test/UnitTests/Microsoft.Testing.Platform.UnitTests/Logging/LoggerFactoryProxyTests.cs
@@ -0,0 +1,44 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+
+using Microsoft.Testing.Platform.Logging;
+
+using Moq;
+
+namespace Microsoft.Testing.Platform.UnitTests;
+
+[TestClass]
+public sealed class LoggerFactoryProxyTests
+{
+    [TestMethod]
+    public void CreateLogger_WhenNotInitialized_ThrowsInvalidOperationException()
+    {
+        LoggerFactoryProxy proxy = new();
+
+        Assert.ThrowsExactly<InvalidOperationException>(() => proxy.CreateLogger("test"));
+    }
+
+    [TestMethod]
+    public void SetLoggerFactory_WithNull_ThrowsArgumentNullException()
+    {
+        LoggerFactoryProxy proxy = new();
+
+        Assert.ThrowsExactly<ArgumentNullException>(() => proxy.SetLoggerFactory(null!));
+    }
+
+    [TestMethod]
+    public void CreateLogger_WhenInitialized_DelegatesToInnerFactory()
+    {
+        Mock<ILogger> mockLogger = new();
+        Mock<ILoggerFactory> mockFactory = new();
+        mockFactory.Setup(f => f.CreateLogger("category")).Returns(mockLogger.Object);
+
+        LoggerFactoryProxy proxy = new();
+        proxy.SetLoggerFactory(mockFactory.Object);
+
+        ILogger result = proxy.CreateLogger("category");
+
+        Assert.AreSame(mockLogger.Object, result);
+        mockFactory.Verify(f => f.CreateLogger("category"), Times.Once);
+    }
+}