microsoft · AArnott · Dec 11, 2025 · Dec 2, 2025 · Dec 2, 2025 · Dec 3, 2025
diff --git a/.github/workflows/docs.yml b/.github/workflows/docs.yml
@@ -42,4 +42,4 @@ jobs:
 
     - name: Deploy to GitHub Pages
       id: deployment
-      uses: actions/deploy-pages@d6db90164ac5ed86f2b6aed7e0febac5b3c0c03e # v4
+      uses: actions/deploy-pages@d6db90164ac5ed86f2b6aed7e0febac5b3c0c03e # v4.0.5
diff --git a/Directory.Packages.props b/Directory.Packages.props
@@ -4,6 +4,7 @@
   <PropertyGroup>
     <ManagePackageVersionsCentrally>true</ManagePackageVersionsCentrally>
     <CentralPackageTransitivePinningEnabled>true</CentralPackageTransitivePinningEnabled>
+    <MicrosoftTestingPlatformVersion>2.0.2</MicrosoftTestingPlatformVersion>
     <MessagePackVersion>2.5.198</MessagePackVersion>
     <MicroBuildVersion>2.0.208</MicroBuildVersion>
     <RoslynVersion>4.14.0</RoslynVersion>
@@ -48,16 +49,13 @@
     <PackageVersion Update="System.IO.Pipelines" Version="9.0.0" />
     <PackageVersion Update="System.Reflection.Metadata" Version="9.0.0" />
   </ItemGroup>
-  <ItemGroup Condition="'$(IsBenchmarksProject)'=='true' or '$(MSBuildProjectName)'=='BenchmarkDotNet.Autogenerated' or '$(IsTestProject)'=='true'">
-    <PackageVersion Update="System.Collections.Immutable" Version="9.0.0" />
-    <PackageVersion Update="System.IO.Pipelines" Version="9.0.0" />
-    <PackageVersion Update="System.Reflection.Metadata" Version="9.0.0" />
-  </ItemGroup>
   <ItemGroup Label="Library.Template">
-    <PackageVersion Include="Microsoft.NET.Test.Sdk" Version="18.0.1" />
+    <PackageVersion Include="Microsoft.Testing.Extensions.CodeCoverage" Version="18.1.0" />
+    <PackageVersion Include="Microsoft.Testing.Extensions.CrashDump" Version="$(MicrosoftTestingPlatformVersion)" />
+    <PackageVersion Include="Microsoft.Testing.Extensions.HangDump" Version="$(MicrosoftTestingPlatformVersion)" />
+    <PackageVersion Include="Microsoft.Testing.Extensions.TrxReport" Version="$(MicrosoftTestingPlatformVersion)" />
     <PackageVersion Include="Microsoft.VisualStudio.Internal.MicroBuild.NonShipping" Version="$(MicroBuildVersion)" />
-    <PackageVersion Include="xunit.runner.visualstudio" Version="3.1.5" />
-    <PackageVersion Include="xunit.v3" Version="3.2.1" />
+    <PackageVersion Include="xunit.v3.mtp-v2" Version="3.2.1" />
   </ItemGroup>
   <ItemGroup>
     <GlobalPackageReference Include="Microsoft.CodeAnalysis.BannedApiAnalyzers" Version="$(CodeAnalysisAnalyzerVersion)" />

diff --git a/azure-pipelines/Merge-CodeCoverage.ps1 b/azure-pipelines/Merge-CodeCoverage.ps1
@@ -28,6 +28,7 @@ try {
     if ($reports) {
         $reports |% { $_.FullName } |% {
             # In addition to replacing {reporoot}, we also normalize on one kind of slash so that the report aggregates data for a file whether data was collected on Windows or not.
+            Write-Verbose "Processing $_"
             $xml = [xml](Get-Content -LiteralPath $_)
             $xml.coverage.packages.package.classes.class |? { $_.filename} |% {
                 $_.filename = $_.filename.Replace('{reporoot}', $RepoRoot).Replace([IO.Path]::AltDirectorySeparatorChar, [IO.Path]::DirectorySeparatorChar)

diff --git a/azure-pipelines/dotnet.yml b/azure-pipelines/dotnet.yml
@@ -20,25 +20,17 @@ steps:
   displayName: 🧪 dotnet test
   condition: and(succeeded(), ${{ parameters.RunTests }})
 
-- task: DotNetCoreCLI@2
+- powershell: tools/dotnet-test-cloud.ps1 -Configuration $(BuildConfiguration) -Agent $(Agent.JobName) -PublishResults -netfxOnly -logIsolationName EventSource-throw
   displayName: 🧪 dotnet test -f net472 (+EventSource throw)
-  inputs:
-    command: test
-    arguments: --no-build -c $(BuildConfiguration) -f net472 --filter "TestCategory!=FailsInCloudTest$(FailsOnMonoFilter)" -v n /p:CollectCoverage=true /bl:"$(Build.ArtifactStagingDirectory)/build_logs/test_net472_etw.binlog" --diag "$(Build.ArtifactStagingDirectory)/test_logs/net472_etw.txt"
-    testRunTitle: streamjsonrpc.tests-etw (net472, $(Agent.JobName))
   env:
     StreamJsonRpc_TestWithEventSource: 1 # allow exceptions from EventSource to propagate
-  condition: and(succeeded(), ne(variables['OptProf'], 'true'), eq(variables['Agent.OS'], 'Windows_NT'))
+  condition: and(succeeded(), eq(variables['Agent.OS'], 'Windows_NT'))
 
-- task: DotNetCoreCLI@2
+- powershell: tools/dotnet-test-cloud.ps1 -Configuration $(BuildConfiguration) -Agent $(Agent.JobName) -PublishResults -netfxOnly -logIsolationName EventSource-production
   displayName: 🧪 dotnet test -f net472 (+EventSource production)
-  inputs:
-    command: test
-    arguments: --no-build -c $(BuildConfiguration) -f net472 --filter "TestCategory!=FailsInCloudTest$(FailsOnMonoFilter)" -v n /p:CollectCoverage=true /bl:"$(Build.ArtifactStagingDirectory)/build_logs/test_net472_etw.binlog" --diag "$(Build.ArtifactStagingDirectory)/test_logs/net472_etw.txt"
-    testRunTitle: streamjsonrpc.tests-etw (net472, $(Agent.JobName))
   env:
     StreamJsonRpc_TestWithEventSource: 2 # swallow exceptions from EventSource, as is done in production
-  condition: and(succeeded(), ne(variables['OptProf'], 'true'), eq(variables['Agent.OS'], 'Windows_NT'))
+  condition: and(succeeded(), eq(variables['Agent.OS'], 'Windows_NT'))
 
 - powershell: tools/variables/_define.ps1
   failOnStderr: true

diff --git a/global.json b/global.json
@@ -1,9 +1,12 @@
 {
   "sdk": {
-    "version": "10.0.100",
+    "version": "10.0.101",
     "rollForward": "patch",
     "allowPrerelease": false
   },
+  "test": {
+    "runner": "Microsoft.Testing.Platform"
+  },
   "msbuild-sdks": {
     "Microsoft.Build.NoTargets": "3.7.134",
     "Microsoft.Build.Traversal": "4.1.82"

diff --git a/test/Benchmarks/Benchmarks.csproj b/test/Benchmarks/Benchmarks.csproj
@@ -3,6 +3,7 @@
   <PropertyGroup>
     <OutputType>Exe</OutputType>
     <TargetFrameworks>net8.0;net472</TargetFrameworks>
+    <IsTestProject>false</IsTestProject>
     <IsBenchmarksProject>true</IsBenchmarksProject>
   </PropertyGroup>
 

diff --git a/test/Directory.Build.props b/test/Directory.Build.props
@@ -5,6 +5,7 @@
   <PropertyGroup>
     <IsPackable>false</IsPackable>
     <CopyLocalLockFileAssemblies>true</CopyLocalLockFileAssemblies>
+    <UseMicrosoftTestingPlatformRunner>true</UseMicrosoftTestingPlatformRunner>
   </PropertyGroup>
 
   <ItemGroup>

diff --git a/test/Directory.Build.targets b/test/Directory.Build.targets
@@ -1,5 +1,11 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project>
+  <ItemGroup Condition="'$(IsTestProject)' != 'false'">
+    <PackageReference Include="Microsoft.Testing.Extensions.CodeCoverage" />
+    <PackageReference Include="Microsoft.Testing.Extensions.CrashDump" />
+    <PackageReference Include="Microsoft.Testing.Extensions.HangDump" />
+    <PackageReference Include="Microsoft.Testing.Extensions.TrxReport" />
+  </ItemGroup>
   <ItemGroup>
     <Content Include="xunit.runner.json" CopyToOutputDirectory="PreserveNewest" Condition="Exists('xunit.runner.json')" />
   </ItemGroup>

diff --git a/test/Directory.Packages.props b/test/Directory.Packages.props
@@ -0,0 +1,10 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project>
+  <Import Project="$([MSBuild]::GetPathOfFileAbove($(MSBuildThisFile), $(MSBuildThisFileDirectory)..))" />
+
+  <ItemGroup>
+    <PackageVersion Update="System.Collections.Immutable" Version="9.0.0" />
+    <PackageVersion Update="System.IO.Pipelines" Version="9.0.0" />
+    <PackageVersion Update="System.Reflection.Metadata" Version="9.0.0" />
+  </ItemGroup>
+</Project>
diff --git a/test/NativeAOTCompatibility.Test/NativeAOTCompatibility.Test.csproj b/test/NativeAOTCompatibility.Test/NativeAOTCompatibility.Test.csproj
@@ -6,6 +6,7 @@
     <TrimmerSingleWarn>false</TrimmerSingleWarn>
     <EmitCompilerGeneratedFiles>true</EmitCompilerGeneratedFiles>
     <EnableStreamJsonRpcInterceptors>true</EnableStreamJsonRpcInterceptors>
+    <IsTestProject>false</IsTestProject>
   </PropertyGroup>
 
   <ItemGroup>

diff --git a/test/StreamJsonRpc.Analyzer.Tests/StreamJsonRpc.Analyzer.Tests.csproj b/test/StreamJsonRpc.Analyzer.Tests/StreamJsonRpc.Analyzer.Tests.csproj
@@ -4,7 +4,6 @@
     <TargetFrameworks>net8.0</TargetFrameworks>
     <TargetFrameworks Condition="'$(OS)' == 'Windows_NT'">$(TargetFrameworks);net472</TargetFrameworks>
     <OutputType>Exe</OutputType>
-    <IsTestProject>true</IsTestProject>
   </PropertyGroup>
 
   <ItemGroup>
@@ -16,9 +15,7 @@
     <PackageReference Include="Microsoft.CodeAnalysis.CSharp" />
     <PackageReference Include="Microsoft.CodeAnalysis.CSharp.CodeFix.Testing.XUnit" />
     <PackageReference Include="Microsoft.CodeAnalysis.CSharp.SourceGenerators.Testing.XUnit" />
-    <PackageReference Include="Microsoft.NET.Test.Sdk" />
-    <PackageReference Include="xunit.v3" />
-    <PackageReference Include="xunit.runner.visualstudio" />
+    <PackageReference Include="xunit.v3.mtp-v2" />
   </ItemGroup>
 
   <ItemGroup>

diff --git a/test/StreamJsonRpc.Tests.ExternalAssembly/StreamJsonRpc.Tests.ExternalAssembly.csproj b/test/StreamJsonRpc.Tests.ExternalAssembly/StreamJsonRpc.Tests.ExternalAssembly.csproj
@@ -3,6 +3,7 @@
   <PropertyGroup>
     <TargetFramework>netstandard2.0</TargetFramework>
     <DisablePolyfills>true</DisablePolyfills>
+    <IsTestProject>false</IsTestProject>
   </PropertyGroup>
 
   <ItemGroup>

diff --git a/test/StreamJsonRpc.Tests.NoInterceptors/StreamJsonRpc.Tests.NoInterceptors.csproj b/test/StreamJsonRpc.Tests.NoInterceptors/StreamJsonRpc.Tests.NoInterceptors.csproj
@@ -31,17 +31,15 @@
     <PackageReference Include="Microsoft.AspNetCore.TestHost" />
     <PackageReference Include="Microsoft.AspNetCore" />
     <PackageReference Include="Microsoft.Bcl.AsyncInterfaces" />
-    <PackageReference Include="Microsoft.NET.Test.Sdk" />
     <PackageReference Include="Microsoft.VisualStudio.Threading.Analyzers" PrivateAssets="all" />
     <PackageReference Include="System.IO.Pipes" />
     <PackageReference Include="System.Net.Http" />
     <PackageReference Include="System.Threading.Tasks.Dataflow" />
     <PackageReference Include="System.ValueTuple" />
     <PackageReference Include="xunit.combinatorial" />
     <PackageReference Include="xunit.runner.console" />
-    <PackageReference Include="xunit.runner.visualstudio" />
     <PackageReference Include="xunit.stafact" />
-    <PackageReference Include="xunit.v3" />
+    <PackageReference Include="xunit.v3.mtp-v2" />
   </ItemGroup>
   <ItemGroup>
     <Reference Include="Microsoft.CSharp" Condition=" '$(TargetFramework)' == 'net472' " />

diff --git a/test/StreamJsonRpc.Tests/StreamJsonRpc.Tests.csproj b/test/StreamJsonRpc.Tests/StreamJsonRpc.Tests.csproj
@@ -73,17 +73,15 @@
     <PackageReference Include="Microsoft.AspNetCore.TestHost" />
     <PackageReference Include="Microsoft.AspNetCore" />
     <PackageReference Include="Microsoft.Bcl.AsyncInterfaces" />
-    <PackageReference Include="Microsoft.NET.Test.Sdk" />
     <PackageReference Include="Microsoft.VisualStudio.Threading.Analyzers" PrivateAssets="all" />
     <PackageReference Include="System.IO.Pipes" />
     <PackageReference Include="System.Net.Http" />
     <PackageReference Include="System.Threading.Tasks.Dataflow" />
     <PackageReference Include="System.ValueTuple" />
     <PackageReference Include="xunit.combinatorial" />
     <PackageReference Include="xunit.runner.console" />
-    <PackageReference Include="xunit.runner.visualstudio" />
     <PackageReference Include="xunit.stafact" />
-    <PackageReference Include="xunit.v3" />
+    <PackageReference Include="xunit.v3.mtp-v2" />
   </ItemGroup>
   <ItemGroup>
     <Reference Include="Microsoft.CSharp" Condition=" '$(TargetFramework)' == 'net472' " />

diff --git a/test/UnreachableAssembly/UnreachableAssembly.csproj b/test/UnreachableAssembly/UnreachableAssembly.csproj
@@ -3,6 +3,7 @@
   <PropertyGroup>
     <TargetFrameworks>net8.0</TargetFrameworks>
     <TargetFrameworks Condition="$([MSBuild]::IsOSPlatform('Windows'))">$(TargetFrameworks);net472</TargetFrameworks>
+    <IsTestProject>false</IsTestProject>
   </PropertyGroup>
 
 </Project>
diff --git a/tools/artifacts/coverageResults.ps1 b/tools/artifacts/coverageResults.ps1
@@ -1,25 +1,26 @@
-$RepoRoot = [System.IO.Path]::GetFullPath("$PSScriptRoot\..\..")
+$RepoRoot = Resolve-Path "$PSScriptRoot\..\.."
 
-$coverageFiles = @(Get-ChildItem "$RepoRoot/test/*.cobertura.xml" -Recurse | Where {$_.FullName -notlike "*/In/*"  -and $_.FullName -notlike "*\In\*" })
+$coverageFilesUnderRoot = @(Get-ChildItem "$RepoRoot/*.cobertura.xml" -Recurse | Where-Object {$_.FullName -notlike "*/In/*"  -and $_.FullName -notlike "*\In\*" })
+
+# Under MTP, coverage files are written directly to the artifacts output directory,
+# so we need to look there too.
+$ArtifactStagingFolder = & "$PSScriptRoot/../Get-ArtifactsStagingDirectory.ps1"
+$directTestLogs = Join-Path $ArtifactStagingFolder test_logs
+$coverageFilesUnderArtifacts = if (Test-Path $directTestLogs) { @(Get-ChildItem "$directTestLogs/*.cobertura.xml" -Recurse) } else { @() }
 
 # Prepare code coverage reports for merging on another machine
-$repoRoot = $env:SYSTEM_DEFAULTWORKINGDIRECTORY
-if (!$repoRoot) { $repoRoot = $env:GITHUB_WORKSPACE }
-if ($repoRoot) {
-    Write-Host "Substituting $repoRoot with `"{reporoot}`""
-    $coverageFiles |% {
-        $content = Get-Content -LiteralPath $_ |% { $_ -Replace [regex]::Escape($repoRoot), "{reporoot}" }
-        Set-Content -LiteralPath $_ -Value $content -Encoding UTF8
-    }
-} else {
-    Write-Warning "coverageResults: Cloud build not detected. Machine-neutral token replacement skipped."
+Write-Host "Substituting $repoRoot with `"{reporoot}`""
+@($coverageFilesUnderRoot + $coverageFilesUnderArtifacts) |? { $_ }|% {
+    $content = Get-Content -LiteralPath $_ |% { $_ -Replace [regex]::Escape($repoRoot), "{reporoot}" }
+    Set-Content -LiteralPath $_ -Value $content -Encoding UTF8
 }
 
 if (!((Test-Path $RepoRoot\bin) -and (Test-Path $RepoRoot\obj))) { return }
 
 @{
+    $directTestLogs = $coverageFilesUnderArtifacts;
     $RepoRoot = (
-        $coverageFiles +
+        $coverageFilesUnderRoot +
         (Get-ChildItem "$RepoRoot\obj\*.cs" -Recurse)
     );
 }
diff --git a/tools/artifacts/testResults.ps1 b/tools/artifacts/testResults.ps1
@@ -4,7 +4,8 @@ Param(
 
 $result = @{}
 
-$testRoot = Resolve-Path "$PSScriptRoot\..\..\test"
+$RepoRoot = Resolve-Path "$PSScriptRoot\..\.."
+$testRoot = Join-Path $RepoRoot test
 $result[$testRoot] = (Get-ChildItem "$testRoot\TestResults" -Recurse -Directory | Get-ChildItem -Recurse -File)
 
 $artifactStaging = & "$PSScriptRoot/../Get-ArtifactsStagingDirectory.ps1"

diff --git a/tools/dotnet-test-cloud.ps1 b/tools/dotnet-test-cloud.ps1
@@ -20,12 +20,14 @@ Param(
     [string]$Agent='Local',
     [switch]$PublishResults,
     [switch]$x86,
-    [string]$dotnet32
+    [string]$dotnet32,
+    [switch]$netfxOnly,
+    [string]$logIsolationName
 )
 
 $RepoRoot = (Resolve-Path "$PSScriptRoot/..").Path
 $ArtifactStagingFolder = & "$PSScriptRoot/Get-ArtifactsStagingDirectory.ps1"
-$FailsOnMonoFilter = & "$PSScriptRoot/variables/FailsOnMonoFilter.ps1"
+$OnCI = ($env:CI -or $env:TF_BUILD)
 
 $dotnet = 'dotnet'
 if ($x86) {
@@ -45,26 +47,70 @@ if ($x86) {
   }
 }
 
-$testBinLog = Join-Path $ArtifactStagingFolder (Join-Path build_logs test.binlog)
-$testDiagLog = Join-Path $ArtifactStagingFolder (Join-Path test_logs diag.log)
+$binlogName = if ($logIsolationName) { "test_$logIsolationName.binlog" } else { "test.binlog" }
+$testBinLog = Join-Path $ArtifactStagingFolder (Join-Path build_logs $binlogName)
 
-& $dotnet test $RepoRoot `
-    --no-build `
-    -c $Configuration `
-    --filter "TestCategory!=FailsInCloudTest$FailsOnMonoFilter" `
-    --collect "Code Coverage;Format=cobertura" `
-    --settings "$PSScriptRoot/test.runsettings" `
-    --blame-hang-timeout 60s `
-    --blame-crash `
-    -bl:"$testBinLog" `
-    --diag "$testDiagLog;TraceLevel=info" `
-    --logger trx `
+$testLogs = Join-Path $ArtifactStagingFolder test_logs
+if ($logIsolationName) {
+    $testLogs = Join-Path $testLogs $logIsolationName
+}
+
+$globalJson = Get-Content $PSScriptRoot/../global.json | ConvertFrom-Json
+$isMTP = $globalJson.test.runner -eq 'Microsoft.Testing.Platform'
+$extraArgs = @()
+
+if ($netfxOnly) {
+    $extraArgs += '--framework','net472'
+}
+
+if ($isMTP) {
+    if ($OnCI) { $extraArgs += '--no-progress' }
+    & $dotnet test --solution $RepoRoot `
+        --no-build `
+        -c $Configuration `
+        -bl:"$testBinLog" `
+        --filter-not-trait 'TestCategory=FailsInCloudTest' `
+        --coverage `
+        --coverage-output-format cobertura `
+        --coverage-settings "$PSScriptRoot/test.runsettings" `
+        --hangdump `
+        --hangdump-timeout 60s `
+        --crashdump `
+        --diagnostic `
+        --diagnostic-output-directory $testLogs `
+        --diagnostic-verbosity Information `
+        --results-directory $testLogs `
+        --report-trx `
+        @extraArgs
+
+    $trxFiles = Get-ChildItem -Recurse -Path $testLogs\*.trx
+} else {
+    $testDiagLog = Join-Path $ArtifactStagingFolder (Join-Path test_logs diag.log)
+    & $dotnet test $RepoRoot `
+        --no-build `
+        -c $Configuration `
+        --filter "TestCategory!=FailsInCloudTest" `
+        --collect "Code Coverage;Format=cobertura" `
+        --settings "$PSScriptRoot/test.runsettings" `
+        --blame-hang-timeout 60s `
+        --blame-crash `
+        -bl:"$testBinLog" `
+        --diag "$testDiagLog;TraceLevel=info" `
+        --logger trx `
+        @extraArgs
+
+    $trxFiles = Get-ChildItem -Recurse -Path $RepoRoot\test\*.trx
+}
 
 $unknownCounter = 0
-Get-ChildItem -Recurse -Path $RepoRoot\test\*.trx |% {
-  Copy-Item $_ -Destination $ArtifactStagingFolder/test_logs/
+$trxFiles |% {
+  New-Item $testLogs -ItemType Directory -Force | Out-Null
+  if (!($_.FullName.StartsWith($testLogs))) {
+    Copy-Item $_ -Destination $testLogs
+  }
 
   if ($PublishResults) {
+    $runTitleIsolationSuffix = if ($logIsolationName) { ", $logIsolationName" } else { "" }
     $x = [xml](Get-Content -LiteralPath $_)
     $runTitle = $null
     if ($x.TestRun.TestDefinitions -and $x.TestRun.TestDefinitions.GetElementsByTagName('UnitTest')) {
@@ -73,13 +119,13 @@ Get-ChildItem -Recurse -Path $RepoRoot\test\*.trx |% {
         if ($matches.rid) {
           $runTitle = "$($matches.lib) ($($matches.tfm), $($matches.rid), $Agent)"
         } else {
-          $runTitle = "$($matches.lib) ($($matches.tfm)$x86RunTitleSuffix, $Agent)"
+          $runTitle = "$($matches.lib) ($($matches.tfm)$x86RunTitleSuffix$runTitleIsolationSuffix, $Agent)"
         }
       }
     }
     if (!$runTitle) {
       $unknownCounter += 1;
-      $runTitle = "unknown$unknownCounter ($Agent$x86RunTitleSuffix)";
+      $runTitle = "unknown$unknownCounter ($Agent$x86RunTitleSuffix$runTitleIsolationSuffix)";
     }
 
     Write-Host "##vso[results.publish type=VSTest;runTitle=$runTitle;publishRunAttachments=true;resultFiles=$_;failTaskOnFailedTests=true;testRunSystem=VSTS - PTR;]"