From f8d744959099d704872e4a09974850df35052c6f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Amaury=20Lev=C3=A9?= <amauryleve@microsoft.com>
Date: Tue, 27 Jan 2026 16:22:59 +0100
Subject: [PATCH] Add trx report acceptance test for MSTest

---
 .../TrxReportTests.cs                         | 94 +++++++++++++++++++
 1 file changed, 94 insertions(+)
 create mode 100644 test/IntegrationTests/MSTest.Acceptance.IntegrationTests/TrxReportTests.cs

diff --git a/test/IntegrationTests/MSTest.Acceptance.IntegrationTests/TrxReportTests.cs b/test/IntegrationTests/MSTest.Acceptance.IntegrationTests/TrxReportTests.cs
new file mode 100644
index 0000000000..2943f72d25
--- /dev/null
+++ b/test/IntegrationTests/MSTest.Acceptance.IntegrationTests/TrxReportTests.cs
@@ -0,0 +1,94 @@
+// 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.Acceptance.IntegrationTests;
+using Microsoft.Testing.Platform.Acceptance.IntegrationTests.Helpers;
+using Microsoft.Testing.Platform.Helpers;
+
+namespace MSTest.Acceptance.IntegrationTests;
+
+[TestClass]
+public sealed class TrxReportTests : AcceptanceTestBase<TrxReportTests.TestAssetFixture>
+{
+    [TestMethod]
+    [DynamicData(nameof(TargetFrameworks.AllForDynamicData), typeof(TargetFrameworks))]
+    public async Task TrxReport_WhenTestFails_ContainsExceptionInfoInOutput(string tfm)
+    {
+        string fileName = Guid.NewGuid().ToString("N");
+        var testHost = TestHost.LocateFrom(AssetFixture.TargetAssetPath, TestAssetFixture.ProjectName, tfm);
+        TestHostResult testHostResult = await testHost.ExecuteAsync($"--report-trx --report-trx-filename {fileName}.trx", cancellationToken: TestContext.CancellationToken);
+
+        testHostResult.AssertExitCodeIs(ExitCodes.AtLeastOneTestFailed);
+
+        string trxFile = Directory.GetFiles(testHost.DirectoryName, $"{fileName}.trx", SearchOption.AllDirectories).Single();
+        string trxContent = File.ReadAllText(trxFile);
+
+        // Verify that the TRX contains the UnitTestResult with outcome="Failed"
+        Assert.Contains(@"<UnitTestResult", trxContent, trxContent);
+        Assert.Contains(@"outcome=""Failed""", trxContent, trxContent);
+
+        // Verify that the TRX contains the Output element with error info
+        Assert.Contains(@"<Output>", trxContent, trxContent);
+        Assert.Contains(@"<ErrorInfo>", trxContent, trxContent);
+
+        // Verify that exception message is present
+        Assert.Contains(@"<Message>", trxContent, trxContent);
+        Assert.Contains("Assert.AreEqual failed. Expected:&lt;1&gt;. Actual:&lt;2&gt;.", trxContent, trxContent);
+
+        // Verify that stack trace is present
+        Assert.Contains(@"<StackTrace>", trxContent, trxContent);
+        Assert.Contains("at MSTestTrxReport.UnitTest1.FailingTest()", trxContent, trxContent);
+    }
+
+    public sealed class TestAssetFixture() : TestAssetFixtureBase(AcceptanceFixture.NuGetGlobalPackagesFolder)
+    {
+        public const string ProjectName = "MSTestTrxReport";
+
+        public string TargetAssetPath => GetAssetPath(ProjectName);
+
+        public override IEnumerable<(string ID, string Name, string Code)> GetAssetsToGenerate()
+        {
+            yield return (ProjectName, ProjectName,
+                SourceCode
+                .PatchTargetFrameworks(TargetFrameworks.All)
+                .PatchCodeWithReplace("$MicrosoftTestingPlatformVersion$", MicrosoftTestingPlatformVersion)
+                .PatchCodeWithReplace("$MSTestVersion$", MSTestVersion));
+        }
+
+        private const string SourceCode = """
+#file MSTestTrxReport.csproj
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <EnableMSTestRunner>true</EnableMSTestRunner>
+    <TargetFrameworks>$TargetFrameworks$</TargetFrameworks>
+    <LangVersion>latest</LangVersion>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Microsoft.Testing.Platform" Version="$MicrosoftTestingPlatformVersion$" />
+    <PackageReference Include="MSTest" Version="$MSTestVersion$" />
+  </ItemGroup>
+
+</Project>
+
+#file UnitTest1.cs
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+
+namespace MSTestTrxReport;
+
+[TestClass]
+public class UnitTest1
+{
+    [TestMethod]
+    public void FailingTest()
+    {
+        Assert.AreEqual(1, 2);
+    }
+}
+""";
+    }
+
+    public TestContext TestContext { get; set; } = null!;
+}