Fix SCI binding failure in DTA hosts (rel/18.7)

Directory.Build.targets

@@ -5,6 +5,16 @@
     <_NetFrameworkHostedCompilersVersion Condition="'$(_NetFrameworkHostedCompilersVersion)' == ''">4.11.0-3.24280.3</_NetFrameworkHostedCompilersVersion>
   </PropertyGroup>
 
+  <PropertyGroup>
+    <!--
+      MSB3277: netstandard2.0 product assemblies reference SCI 9.0.0.0 (from the explicit
+      PackageReference needed for the DTA scenario — see issue #15718), but .NETCoreApp
+      targets have inbox SCI 8.0.0.0. This is harmless: .NET Core assembly loading is
+      version-tolerant and will load the available version regardless of the reference.
+    -->
+    <MSBuildWarningsAsMessages Condition="'$(TargetFrameworkIdentifier)' == '.NETCoreApp'">$(MSBuildWarningsAsMessages);MSB3277</MSBuildWarningsAsMessages>
+  </PropertyGroup>
+
   <Import Project="Sdk.targets" Sdk="Microsoft.DotNet.Arcade.Sdk" />
   <!-- Override the version of imported package to avoid infinite restore loop in VisualStudio, https://github.com/dotnet/arcade/issues/16228 -->
   <ItemGroup>
@@ -70,4 +80,5 @@
     </When>
   </Choose>
 
+
 </Project>

eng/Versions.props

@@ -70,7 +70,7 @@
     <_MicrosoftVSSDKBuildToolsVersion_>17.14.2119</_MicrosoftVSSDKBuildToolsVersion_>
     <MicrosoftWin32RegistryVersion>5.0.0</MicrosoftWin32RegistryVersion>
     <NewtonsoftJsonVersion>13.0.3</NewtonsoftJsonVersion>
-    <SystemCollectionsImmutableVersion>9.0.11</SystemCollectionsImmutableVersion>
+    <SystemCollectionsImmutableVersion>10.0.0</SystemCollectionsImmutableVersion>
     <SystemMemoryVersion>4.6.3</SystemMemoryVersion>
     <SystemReflectionMetadataVersion>8.0.0</SystemReflectionMetadataVersion>
     <TestPlatformExternalsVersion>18.0.0-preview-1-10911-061</TestPlatformExternalsVersion>

src/Microsoft.TestPlatform.CoreUtilities/Microsoft.TestPlatform.CoreUtilities.csproj

@@ -19,6 +19,7 @@
   <ItemGroup>
     <PackageReference Include="Microsoft.Win32.Registry" Version="$(MicrosoftWin32RegistryVersion)" Condition="'$(TargetFramework)' == 'netstandard2.0'" />
     <PackageReference Include="System.Reflection.Metadata" Version="$(SystemReflectionMetadataVersion)" Condition="'$(TargetFrameworkIdentifier)' != '.NETCoreApp'" />
+    <PackageReference Include="System.Collections.Immutable" Version="$(SystemCollectionsImmutableVersion)" Condition="'$(TargetFrameworkIdentifier)' == '.NETFramework'" />
   </ItemGroup>
 
   <ItemGroup>

src/Microsoft.TestPlatform.ObjectModel/Microsoft.TestPlatform.ObjectModel.csproj

@@ -37,6 +37,7 @@
     <PackageReference Include="System.ValueTuple" Version="4.5.0" 
         Condition="$([MSBuild]::IsTargetFrameworkCompatible('$(TargetFramework)', 'net48')) != 'true' and '$(TargetFrameworkIdentifier)' == '.NETFramework'" />
     <PackageReference Include="System.Reflection.Metadata" Version="$(SystemReflectionMetadataVersion)" Condition="'$(TargetFrameworkIdentifier)' != '.NETCoreApp'" />
+    <PackageReference Include="System.Collections.Immutable" Version="$(SystemCollectionsImmutableVersion)" Condition="'$(TargetFrameworkIdentifier)' == '.NETFramework'" />
   </ItemGroup>
 
   <ItemGroup>

src/datacollector/app.config

@@ -22,11 +22,19 @@
       </dependentAssembly>
       <dependentAssembly>
         <assemblyIdentity name="System.Runtime.CompilerServices.Unsafe" publicKeyToken="b03f5f7f11d50a3a" culture="neutral" />
-        <bindingRedirect oldVersion="0.0.0.0-6.0.0.0" newVersion="6.0.0.0" />
+        <bindingRedirect oldVersion="0.0.0.0-6.0.3.0" newVersion="6.0.3.0" />
+      </dependentAssembly>
+      <dependentAssembly>
+        <assemblyIdentity name="System.Memory" publicKeyToken="cc7b13ffcd2ddd51" culture="neutral" />
+        <bindingRedirect oldVersion="0.0.0.0-4.0.5.0" newVersion="4.0.5.0" />
+      </dependentAssembly>
+      <dependentAssembly>
+        <assemblyIdentity name="System.Buffers" publicKeyToken="cc7b13ffcd2ddd51" culture="neutral" />
+        <bindingRedirect oldVersion="0.0.0.0-4.0.5.0" newVersion="4.0.5.0" />
       </dependentAssembly>
       <dependentAssembly>
         <assemblyIdentity name="System.Collections.Immutable" publicKeyToken="b03f5f7f11d50a3a" culture="neutral" />
-        <bindingRedirect oldVersion="1.0.0.0-9.0.0.0" newVersion="9.0.0.0" />
+        <bindingRedirect oldVersion="1.0.0.0-10.0.0.0" newVersion="10.0.0.0" />
       </dependentAssembly>
       <dependentAssembly>
         <assemblyIdentity name="System.Reflection.Metadata" publicKeyToken="b03f5f7f11d50a3a" culture="neutral" />

src/package/Microsoft.TestPlatform.CLI/Microsoft.TestPlatform.CLI.csproj

@@ -37,7 +37,7 @@
       Sometimes NU1702 is not suppressed correctly, so force reducing severity of the warning.
       See https://github.com/NuGet/Home/issues/9147
     -->
-    <MSBuildWarningsAsMessages>NU1702</MSBuildWarningsAsMessages>
+    <MSBuildWarningsAsMessages>$(MSBuildWarningsAsMessages);NU1702</MSBuildWarningsAsMessages>
   </PropertyGroup>
 
   <!-- runner and runner dependencies -->

src/package/Microsoft.TestPlatform.Portable/Microsoft.TestPlatform.Portable.csproj

@@ -12,7 +12,7 @@
       Sometimes NU1702 is not suppressed correctly, so force reducing severity of the warning.
       See https://github.com/NuGet/Home/issues/9147
     -->
-    <MSBuildWarningsAsMessages>NU1702</MSBuildWarningsAsMessages>
+    <MSBuildWarningsAsMessages>$(MSBuildWarningsAsMessages);NU1702</MSBuildWarningsAsMessages>
   </PropertyGroup>
 
   <PropertyGroup>

src/package/Microsoft.TestPlatform/Microsoft.TestPlatform.csproj

@@ -11,7 +11,7 @@
       Sometimes NU1702 is not suppressed correctly, so force reducing severity of the warning.
       See https://github.com/NuGet/Home/issues/9147
     -->
-    <MSBuildWarningsAsMessages>NU1702;NETSDK1023</MSBuildWarningsAsMessages>
+    <MSBuildWarningsAsMessages>$(MSBuildWarningsAsMessages);NU1702;NETSDK1023</MSBuildWarningsAsMessages>
   </PropertyGroup>
 
   <PropertyGroup>

src/testhost.x86/app.config

@@ -35,11 +35,19 @@
       </dependentAssembly>
       <dependentAssembly>
         <assemblyIdentity name="System.Runtime.CompilerServices.Unsafe" publicKeyToken="b03f5f7f11d50a3a" culture="neutral" />
-        <bindingRedirect oldVersion="0.0.0.0-6.0.0.0" newVersion="6.0.0.0" />
+        <bindingRedirect oldVersion="0.0.0.0-6.0.3.0" newVersion="6.0.3.0" />
+      </dependentAssembly>
+      <dependentAssembly>
+        <assemblyIdentity name="System.Memory" publicKeyToken="cc7b13ffcd2ddd51" culture="neutral" />
+        <bindingRedirect oldVersion="0.0.0.0-4.0.5.0" newVersion="4.0.5.0" />
+      </dependentAssembly>
+      <dependentAssembly>
+        <assemblyIdentity name="System.Buffers" publicKeyToken="cc7b13ffcd2ddd51" culture="neutral" />
+        <bindingRedirect oldVersion="0.0.0.0-4.0.5.0" newVersion="4.0.5.0" />
       </dependentAssembly>
       <dependentAssembly>
         <assemblyIdentity name="System.Collections.Immutable" publicKeyToken="b03f5f7f11d50a3a" culture="neutral" />
-        <bindingRedirect oldVersion="1.0.0.0-9.0.0.0" newVersion="9.0.0.0" />
+        <bindingRedirect oldVersion="1.0.0.0-10.0.0.0" newVersion="10.0.0.0" />
       </dependentAssembly>
       <dependentAssembly>
         <assemblyIdentity name="System.Reflection.Metadata" publicKeyToken="b03f5f7f11d50a3a" culture="neutral" />

src/vstest.console/app.config

@@ -27,11 +27,11 @@
       </dependentAssembly>
       <dependentAssembly>
         <assemblyIdentity name="System.Runtime.CompilerServices.Unsafe" publicKeyToken="b03f5f7f11d50a3a" culture="neutral" />
-        <bindingRedirect oldVersion="0.0.0.0-6.0.0.0" newVersion="6.0.0.0" />
+        <bindingRedirect oldVersion="0.0.0.0-6.0.3.0" newVersion="6.0.3.0" />
       </dependentAssembly>
       <dependentAssembly>
         <assemblyIdentity name="System.Collections.Immutable" publicKeyToken="b03f5f7f11d50a3a" culture="neutral" />
-        <bindingRedirect oldVersion="1.0.0.0-9.0.0.0" newVersion="9.0.0.0" />
+        <bindingRedirect oldVersion="1.0.0.0-10.0.0.0" newVersion="10.0.0.0" />
       </dependentAssembly>
       <dependentAssembly>
         <assemblyIdentity name="System.Reflection.Metadata" publicKeyToken="b03f5f7f11d50a3a" culture="neutral" />
@@ -40,7 +40,12 @@
 
       <dependentAssembly>
         <assemblyIdentity name="System.Memory" publicKeyToken="cc7b13ffcd2ddd51" culture="neutral" />
-        <bindingRedirect oldVersion="0.0.0.0-4.0.1.2" newVersion="4.0.1.2" />
+        <bindingRedirect oldVersion="0.0.0.0-4.0.5.0" newVersion="4.0.5.0" />
+      </dependentAssembly>
+
+      <dependentAssembly>
+        <assemblyIdentity name="System.Buffers" publicKeyToken="cc7b13ffcd2ddd51" culture="neutral" />
+        <bindingRedirect oldVersion="0.0.0.0-4.0.5.0" newVersion="4.0.5.0" />
       </dependentAssembly>
 
       <dependentAssembly>
@@ -55,7 +60,7 @@
 
       <dependentAssembly>
         <assemblyIdentity name="System.Text.Json" publicKeyToken="cc7b13ffcd2ddd51" culture="neutral" />
-        <bindingRedirect oldVersion="0.0.0.0-6.0.0.11" newVersion="6.0.0.11" />
+        <bindingRedirect oldVersion="0.0.0.0-6.0.0.11" newVersion="6.0.0.0" />
       </dependentAssembly>
     </assemblyBinding>
   </runtime>

test/Microsoft.TestPlatform.Acceptance.IntegrationTests/DiscoveryTests.cs

@@ -6,6 +6,7 @@
 using System.IO;
 using System.Linq;
 using System.Reflection;
+using System.Runtime.Loader;
 
 using Microsoft.TestPlatform.TestUtilities;
 using Microsoft.VisualStudio.TestPlatform.Common.Utilities;
@@ -106,15 +107,37 @@ public void TypesToLoadAttributeTests()
             }
         };
 
-        foreach (var extension in extensionsToVerify.Keys)
+        // Use a custom AssemblyLoadContext so that dependencies (e.g. SCI 10.0.0)
+        // resolve from the extensions directory rather than the test host's runtime.
+        var parentDirectory = Path.GetDirectoryName(extensionsDirectory)!;
+        var alc = new AssemblyLoadContext("ExtensionTest", isCollectible: true);
+        alc.Resolving += (context, name) =>
         {
-            var assemblyFile = Path.Combine(extensionsDirectory, extension);
-            var assembly = Assembly.LoadFrom(assemblyFile);
+            var path = Path.Combine(extensionsDirectory, name.Name + ".dll");
+            if (File.Exists(path))
+                return context.LoadFromAssemblyPath(path);
+            path = Path.Combine(parentDirectory, name.Name + ".dll");
+            if (File.Exists(path))
+                return context.LoadFromAssemblyPath(path);
+            return null;
+        };
+
+        try
+        {
+            foreach (var extension in extensionsToVerify.Keys)
+            {
+                var assemblyFile = Path.Combine(extensionsDirectory, extension);
+                var assembly = alc.LoadFromAssemblyPath(assemblyFile);
 
-            var expected = extensionsToVerify[extension];
-            var actual = TypesToLoadUtilities.GetTypesToLoad(assembly).Select(i => i.FullName).ToArray();
+                var expected = extensionsToVerify[extension];
+                var actual = TypesToLoadUtilities.GetTypesToLoad(assembly).Select(i => i.FullName).ToArray();
 
-            CollectionAssert.AreEquivalent(expected, actual, $"Specified types using TypesToLoadAttribute in \"{extension}\" assembly doesn't match the expected.");
+                CollectionAssert.AreEquivalent(expected, actual, $"Specified types using TypesToLoadAttribute in \"{extension}\" assembly doesn't match the expected.");
+            }
+        }
+        finally
+        {
+            alc.Unload();
         }
     }
 

test/Microsoft.TestPlatform.Acceptance.IntegrationTests/DistributedTestAgentScenarioTests.cs

@@ -0,0 +1,100 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+
+using System;
+using System.IO;
+using System.Linq;
+using System.Reflection.Metadata;
+using System.Reflection.PortableExecutable;
+
+using Microsoft.TestPlatform.TestUtilities;
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+
+namespace Microsoft.TestPlatform.AcceptanceTests;
+
+/// <summary>
+/// Tests that the DTA (Distributed Test Agent) scenario works: a .NET Framework host
+/// loads Microsoft.VisualStudio.TestPlatform.Common.dll without binding redirects. The shipped
+/// System.Collections.Immutable DLL must match the assembly version referenced by
+/// the compiled product assemblies.
+/// </summary>
+[TestClass]
+public class DistributedTestAgentScenarioTests : AcceptanceTestBase
+{
+    /// <summary>
+    /// Validates that the Microsoft.TestPlatform nupkg layout (used by DTA/VSTest task)
+    /// contains a System.Collections.Immutable whose assembly version matches what
+    /// Common.dll was compiled against.
+    /// </summary>
+    [TestMethod]
+    public void NupkgLayout_CommonDll_CanLoadSciWithoutBindingRedirects()
+    {
+        var testPlatformDir = Path.Combine(
+            IntegrationTestEnvironment.PublishDirectory,
+            $"Microsoft.TestPlatform.{IntegrationTestEnvironment.LatestLocallyBuiltNugetVersion}.nupkg",
+            "tools", "net462", "Common7", "IDE", "Extensions", "TestPlatform");
+
+        ValidateDtaScenario(testPlatformDir, "nupkg");
+    }
+
+    /// <summary>
+    /// Validates that the V2.CLI VSIX layout also has matching SCI assembly versions.
+    /// </summary>
+    [TestMethod]
+    public void VsixLayout_CommonDll_CanLoadSciWithoutBindingRedirects()
+    {
+        var vsixDir = Path.GetDirectoryName(IntegrationTestEnvironment.LocalVsixInsertion);
+        if (vsixDir is null || !Directory.Exists(vsixDir))
+        {
+            Assert.Inconclusive("VSIX directory not found. Build with -pack to produce it.");
+        }
+
+        var vsixExtractDir = Path.Combine(IntegrationTestEnvironment.ArtifactsTempDirectory, "vsix-extracted");
+        if (!Directory.Exists(vsixExtractDir))
+        {
+            System.IO.Compression.ZipFile.ExtractToDirectory(IntegrationTestEnvironment.LocalVsixInsertion, vsixExtractDir);
+        }
+
+        ValidateDtaScenario(vsixExtractDir, "VSIX");
+    }
+
+    private static void ValidateDtaScenario(string testPlatformDir, string layoutName)
+    {
+        Assert.IsTrue(Directory.Exists(testPlatformDir), $"{layoutName} directory not found: {testPlatformDir}");
+
+        var commonDll = Path.Combine(testPlatformDir, "Microsoft.VisualStudio.TestPlatform.Common.dll");
+        var sciDll = Path.Combine(testPlatformDir, "System.Collections.Immutable.dll");
+
+        Assert.IsTrue(File.Exists(commonDll), $"Common.dll not found in {layoutName} layout: {commonDll}");
+        Assert.IsTrue(File.Exists(sciDll), $"System.Collections.Immutable.dll not found in {layoutName} layout: {sciDll}");
+
+        var sciVersion = System.Reflection.AssemblyName.GetAssemblyName(sciDll).Version;
+        var sciRefVersion = GetReferencedAssemblyVersion(commonDll, "System.Collections.Immutable");
+
+        Assert.IsNotNull(sciRefVersion, $"Common.dll in {layoutName} layout does not reference System.Collections.Immutable");
+
+        // For DTA scenario (no binding redirects), these MUST match exactly.
+        Assert.AreEqual(
+            sciRefVersion,
+            sciVersion,
+            $"{layoutName} layout: Common.dll references SCI {sciRefVersion} but shipped DLL is {sciVersion}. " +
+            $"DTA hosts without binding redirects will fail with FileLoadException.");
+    }
+
+    private static Version? GetReferencedAssemblyVersion(string assemblyPath, string referenceName)
+    {
+        using var stream = File.OpenRead(assemblyPath);
+        using var peReader = new PEReader(stream);
+        var mdReader = peReader.GetMetadataReader();
+        foreach (var handle in mdReader.AssemblyReferences)
+        {
+            var asmRef = mdReader.GetAssemblyReference(handle);
+            if (mdReader.GetString(asmRef.Name) == referenceName)
+            {
+                return asmRef.Version;
+            }
+        }
+
+        return null;
+    }
+}