Migrate Microsoft.Extensions.DotNetDeltaApplier.Tests to MSTest.Sdk by Evangelink · Pull Request #54730 · dotnet/sdk

Evangelink · 2026-06-11T21:34:26Z

Summary

Builds on Migrate Microsoft.DotNet.HotReload.Watch.Aspire.Tests to MSTest.Sdk on MTP (pathfinder) #54722 to migrate test/Microsoft.Extensions.DotNetDeltaApplier.Tests from xUnit to MSTest.Sdk on MTP.
Sets UseMSTestSdk=true, replaces xUnit attributes/assertions with MSTest equivalents, and removes the Microsoft.NET.TestFramework project reference.
Replaces Xunit.Combinatorial with Combinatorial.MSTest 2.0.0 and adds the Dependabot package version.
Replaces ITestOutputHelper usage with MSTest TestContext through a project-local TestLogger.

Validation

Q:\src\sdk\.dotnet\dotnet.exe build test\Microsoft.Extensions.DotNetDeltaApplier.Tests\Microsoft.Extensions.DotNetDeltaApplier.Tests.csproj (0 warnings, 0 errors)
Q:\src\sdk\.dotnet\dotnet.exe exec artifacts\bin\Microsoft.Extensions.DotNetDeltaApplier.Tests\Debug\net11.0\Microsoft.Extensions.DotNetDeltaApplier.Tests.dll (121 passed)

TestFX issues

None filed.

Evangelink · 2026-06-12T11:31:05Z

Replaced the manual <UseMSTestSdk>true</UseMSTestSdk> opt-in with the property MSTest.Sdk already sets for us: UsingMSTestSdk. Since MSTest.Sdk's Sdk.props runs before Microsoft.NET.Sdk.props and test/Directory.Build.targets is imported at the bottom of evaluation, the property is in scope wherever we need it — no per-project knob required.

Also refreshed the related comments in XUnitPublish.targets / XUnitRunner.targets and renamed the intermediate _UseMSTestSdk MSBuild property to _UsingMSTestSdk for clarity. (Thanks @Evangelink for the catch.)

Evangelink · 2026-06-12T11:37:54Z

Made --report-trx conditional on Microsoft.Testing.Extensions.TrxReport actually being loaded. MSTest.Sdk enables that extension by default via EnableMicrosoftTestingExtensionsTrxReport=true for the Default / AllMicrosoft profiles, but other MTP hosts (xUnit v3 MTP, MSTest.Sdk with TestingExtensionsProfile=None, etc.) do not — passing --report-trx there fails with 'unknown argument'.

The new GetTrxReportEnabled target queries that property; XUnitRunner.targets propagates it as EnableTrxReport metadata, and SDKCustomCreateXUnitWorkItemsWithTestExclusion only emits the flag when it's true. No behavioural change for the current PRs since all migrated projects are MSTest.Sdk-based, but the dispatcher is now forward-safe.

(Applied to all 9 stacked PRs since they share these plumbing files.)

Evangelink · 2026-06-12T11:37:57Z

Replaced the custom <UseMSTestSdk> opt-in property with the built-in UsingMSTestSdk property that MSTest.Sdk already sets in its Sdk.props before Directory.Build.props is evaluated. This drops a redundant declaration in every migrated csproj and just reads what the SDK already publishes.

Evangelink · 2026-06-12T12:09:51Z

Round 3: moved FluentAssertions Using and AwesomeAssertions PackageReference to test/Directory.Build.targets.

The Using is now global for any test project ('$(IsTestProject)' == 'true' OR '$(UsingMSTestSdk)' == 'true'). The PackageReference is added for MSTest.Sdk projects only — xUnit projects already get it transitively via the Microsoft.NET.TestFramework project reference.

Deviation from your literal suggestion: I left the Microsoft.NET.TestFramework.* Usings and Xunit Using gated on UsingMSTestSdk != true. Moving them unconditional would also require a global <ProjectReference Include="Microsoft.NET.TestFramework" /> (otherwise MSTest projects would fail with CS0246), which would drag xunit.v3.assert and other xUnit pieces into the MSTest projects. Happy to apply the broader change (with a global ProjectRef) if you'd prefer.

Copilot

Pull request overview

Migrates Microsoft.Extensions.DotNetDeltaApplier.Tests (and updates related watch/Aspire tests) from xUnit to MSTest.Sdk on Microsoft.Testing.Platform, and updates Helix dispatching to correctly execute MTP-based test assemblies.

Changes:

Convert multiple test projects/files from xUnit attributes/asserts to MSTest equivalents and introduce an MSTest TestContext-based TestLogger.
Update Helix/xunit-runner infrastructure to detect MTP + TRX capability and switch execution from dotnet test to dotnet exec when needed.
Add/adjust dependencies and build configuration for MSTest.Sdk + combinatorial data and update internals visibility for moved integration tests.

Show a summary per file

File	Description
test/xunit-runner/XUnitRunner.targets	Captures per-project metadata to detect MTP and TRX capability for Helix work item generation.
test/xunit-runner/XUnitPublish.targets	Adds MSBuild targets exposing MTP/TRX detection values to the xunit-runner pipeline.
test/HelixTasks/SDKCustomCreateXUnitWorkItemsWithTestExclusion.cs	Switches Helix command-line to `dotnet exec` for MTP projects and conditionally adds `--report-trx`.
test/Directory.Build.targets	Gates xUnit-only global usings and adds AwesomeAssertions for MSTest.Sdk projects.
test/Microsoft.Extensions.DotNetDeltaApplier.Tests/Microsoft.Extensions.DotNetDeltaApplier.Tests.csproj	Migrates project to `MSTest.Sdk`, updates references, and adds combinatorial MSTest dependency.
test/Microsoft.Extensions.DotNetDeltaApplier.Tests/Mocks/TestLogger.cs	Adds MSTest-friendly logger that writes via `TestContext`.
test/Microsoft.Extensions.DotNetDeltaApplier.Tests/StreamExtensionsTests.cs	Converts combinatorial tests and assertions from xUnit to MSTest.
test/Microsoft.Extensions.DotNetDeltaApplier.Tests/StaticAssetUpdateRequestTests.cs	Converts test attributes/assertions from xUnit to MSTest.
test/Microsoft.Extensions.DotNetDeltaApplier.Tests/ManagedCodeUpdateRequestTests.cs	Converts test attributes/assertions from xUnit to MSTest, including sequence asserts.
test/Microsoft.Extensions.DotNetDeltaApplier.Tests/HotReloadClientTests.cs	Replaces `ITestOutputHelper` with `TestContext` and updates assertions.
test/Microsoft.Extensions.DotNetDeltaApplier.Tests/HotReloadAgentTest.cs	Converts the suite to MSTest, including OS gating and updated assert APIs.
test/Microsoft.DotNet.HotReload.Watch.Aspire.Tests/Microsoft.DotNet.HotReload.Watch.Aspire.Tests.csproj	Switches Aspire unit tests to `MSTest.Sdk` and simplifies references.
test/Microsoft.DotNet.HotReload.Watch.Aspire.Tests/AspireServerLauncherCliTests.cs	Converts xUnit tests/asserts to MSTest equivalents.
test/Microsoft.DotNet.HotReload.Watch.Aspire.Tests/AspireResourceLauncherCliTests.cs	Converts xUnit tests/asserts to MSTest equivalents and preserves FluentAssertions usage.
test/Microsoft.DotNet.HotReload.Watch.Aspire.Tests/AspireHostLauncherTests.cs	Converts xUnit tests/asserts to MSTest equivalents.
test/Microsoft.DotNet.HotReload.Watch.Aspire.Tests/AspireHostLauncherCliTests.cs	Converts xUnit tests/asserts to MSTest equivalents.
test/dotnet-watch.Tests/dotnet-watch.Tests.csproj	Adds reference needed for moved Aspire launcher integration tests.
test/dotnet-watch.Tests/Aspire/PipeUtilities.cs	Introduces helper for reading Watch status events from a named pipe (integration tests support).
test/dotnet-watch.Tests/Aspire/AspireLauncherIntegrationTests.cs	Renames/moves Aspire launcher integration test class (stays on xUnit).
src/Dotnet.Watch/Watch.Aspire/Properties/AssemblyInfo.cs	Adds `InternalsVisibleTo` for `dotnet-watch.Tests` to support moved integration tests.
global.json	Pins `MSTest.Sdk` MSBuild SDK version.
eng/dependabot/Packages.props	Adds Dependabot-managed version pin for `Combinatorial.MSTest`.

Copilot's findings

Files reviewed: 21/22 changed files
Comments generated: 3

+    public IDisposable? BeginScope<TState>(TState state)
+        where TState : notnull => throw new NotImplementedException();
+
+    public bool IsEnabled(LogLevel logLevel)
+        => IsEnabledImpl(logLevel);


+<Project Sdk="MSTest.Sdk">

  <PropertyGroup>
+    <RestoreAdditionalProjectSources>$(RestoreAdditionalProjectSources);https://api.nuget.org/v3/index.json</RestoreAdditionalProjectSources>


+                    string envPrefix;
+                    if (IsPosixShell)
+                    {
+                        envPrefix = $"HELIX_WORK_ITEM_TIMEOUT={timeout} ";
+                    }
+                    else
+                    {
+                        envPrefix = $"set HELIX_WORK_ITEM_TIMEOUT={timeout}&& ";
+                    }


…n MTP This is a pathfinder PR for migrating the test suite to MSTest on Microsoft.Testing.Platform (MTP). Microsoft.DotNet.HotReload.Watch.Aspire.Tests was chosen because it has no dependency on the shared Microsoft.NET.TestFramework (which is xUnit-coupled and referenced by ~57 of 78 test projects), so it can migrate in isolation without unblocking dependents first. Changes: * global.json: add MSTest.Sdk 4.3.0-preview.26307.5 to msbuild-sdks. * test/Directory.Build.targets: gate the xUnit defaults (TestRunnerName=XUnitV3, Using Include=Xunit, etc.) behind $(UseMSTestSdk) != true, so MSTest.Sdk projects opt out cleanly. * test/Microsoft.DotNet.HotReload.Watch.Aspire.Tests: - csproj now uses Sdk="MSTest.Sdk", sets UseMSTestSdk=true, references AwesomeAssertions and only the Watch.Aspire project. MTP is on by default via MSTest.Sdk (EnableMSTestRunner + TestingPlatformDotnetTestSupport). - All 4 unit-test files converted from xUnit to MSTest attributes/asserts ([Fact]/[Theory] -> [TestMethod]/[DataRow], Assert.* equivalents, Assert.IsInstanceOfType<T>, Assert.HasCount, Assert.IsEmpty). - Local AssertEx.SequenceEqual<T> helper replaces the xUnit-coupled one from HotReload.Test.Utilities. * Move the 2 integration tests (AspireLauncherTests + PipeUtilities) to test/dotnet-watch.Tests/Aspire/ so the Aspire.Tests project stays a pure MSTest unit-test project. They keep xUnit because they depend on WatchSdkTest, WatchableApp, [PlatformSpecificFact], ITestOutputHelper and TestAssets from Microsoft.NET.TestFramework. AspireLauncherTests was renamed to AspireLauncherIntegrationTests to reflect its new role. * src/Dotnet.Watch/Watch.Aspire/Properties/AssemblyInfo.cs: grant InternalsVisibleTo to dotnet-watch.Tests (needed by PipeUtilities, which uses internal WatchStatusEvent). * test/dotnet-watch.Tests/dotnet-watch.Tests.csproj: add ProjectReference to Watch.Aspire (ExcludeAssets=Runtime) so the moved integration tests compile. Verification: * Microsoft.DotNet.HotReload.Watch.Aspire.Tests builds with MSTest.Sdk and all 58 unit tests pass under MTP (705 ms). * test/dotnet-watch.Tests builds successfully with the moved files. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

- Bumps MSTest.Sdk to the latest internal preview to pick up the newest 4.3 assertion APIs (Assert.ContainsSingle, Assert.Contains for strings with the more natural (needle, haystack) signature, etc.). - Applies the assertion mapping flagged by the migrate-xunit-to-mstest skill in this repo (.github/skills/migrate-xunit-to-mstest, PR dotnet#54727): Assert.HasCount(1, x) -> Assert.ContainsSingle(x) (one occurrence in AspireResourceLauncherCliTests.cs) Verified: 58/58 tests still pass. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

…parity Per reviewer feedback: MSTest 4.1.0+ exposes Assert.IsExactInstanceOfType<T>(value) which returns T and enforces exact-type semantics -- the proper equivalent of xUnit's Assert.IsType<T>(x). Assert.IsInstanceOfType<T> is the equivalent of xUnit's Assert.IsAssignableFrom<T> (assignable, not exact), which would be a silent semantic regression for the IsType<T> originals. All 39 occurrences across AspireHostLauncherCliTests.cs, AspireResourceLauncherCliTests.cs, AspireServerLauncherCliTests.cs, and AspireLauncherIntegrationTests.cs were originally Assert.IsType<T> in xUnit (verified against main), so all 39 are flipped to Assert.IsExactInstanceOfType<T>. Note: the migrate-xunit-to-mstest skill cheatsheet at .github/skills/migrate-xunit-to-mstest/references/mapping-cheatsheet.md recommends `Assert.IsInstanceOfType<T>` plus an extra typeof-check for exact-type semantics; that guidance predates IsExactInstanceOfType being available. Follow-up upstream (dotnet/skills) suggested. Verified: 58/58 Aspire tests still pass; dotnet-watch.Tests builds clean. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

MSTest.Sdk already adds this as an implicit global using. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

MSTest 4.3+ provides Assert.AreSequenceEqual for element-wise IEnumerable<T> compare with a nice diff message, so the project-local AssertEx helper is no longer needed. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

@Evangelink

…est/Directory.Build.targets Per @Evangelink: keep per-csproj boilerplate minimal. FluentAssertions is now a global using for any test project (gated on IsTestProject OR UsingMSTestSdk), and AwesomeAssertions is added as a PackageReference for MSTest.Sdk projects. xUnit projects continue to pick it up transitively via Microsoft.NET.TestFramework. The Microsoft.NET.TestFramework.* and Xunit usings remain gated on the xUnit branch (UsingMSTestSdk != true) because MSTest projects in this repo do not reference Microsoft.NET.TestFramework; making those usings global would fail with CS0246. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

The recent `Helix dispatcher: gate --report-trx on TrxReport extension being loaded` commit accidentally removed the ProjectReference to Microsoft.DotNet.HotReload.Watch.Aspire from dotnet-watch.Tests.csproj (introduced in the `Migrate Microsoft.DotNet.HotReload.Watch.Aspire.Tests to MSTest.Sdk on MTP` commit to allow the moved AspireLauncherIntegrationTests and PipeUtilities to compile). Without that reference, the build fails with: error CS0246: The type or namespace name 'WatchStatusEvent' could not be found (are you missing a using directive or an assembly reference?) [test/dotnet-watch.Tests/Aspire/PipeUtilities.cs] Re-add the ProjectReference. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Introduces an MSTest-flavored counterpart to the xUnit-based Microsoft.DotNet.HotReload.Test.Utilities so that test helpers that need MSTest's TestContext (e.g. TestLogger, TestLoggerFactory) can be shared across MSTest.Sdk test projects instead of being copy-pasted per project. This commit also migrates the inline TestLogger from Microsoft.DotNet.HotReload.Client.Tests to consume the shared project, which serves as the first reference consumer. Subsequent migration PRs (DeltaApplier.Tests, Containers.UnitTests) will adopt the same project reference instead of adding their own TestLogger/TestLoggerFactory copies. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

- Switch SDK to MSTest.Sdk; set UseMSTestSdk=true to opt out of test/Directory.Build.targets xUnit defaults. - Replace [Fact]/[Theory] + [InlineData] with [TestMethod] + [DataRow]. - Replace Xunit.Combinatorial with Combinatorial.MSTest 2.0.0 (added to eng/dependabot/Packages.props). - Replace ITestOutputHelper with TestContext via a project-local TestLogger. - Replace xUnit assertions with MSTest assertions and remove the Microsoft.NET.TestFramework reference. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

…Sdk) MSTest.Sdk already sets $(UsingMSTestSdk)=true in its Sdk.props before Directory.Build.props is evaluated, so the custom <UseMSTestSdk>true</UseMSTestSdk> opt-in property is redundant. This change: - Removes <UseMSTestSdk>true</UseMSTestSdk> from MSTest.Sdk csproj(s). - Renames $(UseMSTestSdk) -> $(UsingMSTestSdk) in test/Directory.Build.targets (the xUnit-defaults gating condition) and in xunit-runner/{XUnitPublish,XUnitRunner}.targets (Helix MTP dispatcher detection).

--report-trx is an MTP CLI argument provided only when the Microsoft.Testing.Extensions.TrxReport extension is loaded on the test host. MSTest.Sdk's Default/AllMicrosoft profiles enable it by default, but other MTP runners (e.g. xUnit v3 MTP) do not bundle the extension, so passing --report-trx to those hosts fails with 'unknown argument'. XUnitPublish.targets now exposes the GetTrxReportEnabled target which returns the value of EnableMicrosoftTestingExtensionsTrxReport. XUnitRunner.targets calls that target and propagates the value as the EnableTrxReport metadata of SDKCustomXUnitProject items. SDKCustomCreateXUnitWorkItemsWithTestExclusion reads that metadata and only appends --report-trx to the MTP command line when it is true. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

The recent `Helix dispatcher: gate --report-trx on TrxReport extension being loaded` commit accidentally removed the ProjectReference to Microsoft.DotNet.HotReload.Watch.Aspire from dotnet-watch.Tests.csproj (introduced in the `Migrate Microsoft.DotNet.HotReload.Watch.Aspire.Tests to MSTest.Sdk on MTP` commit to allow the moved AspireLauncherIntegrationTests and PipeUtilities to compile). Without that reference, the build fails with: error CS0246: The type or namespace name 'WatchStatusEvent' could not be found (are you missing a using directive or an assembly reference?) [test/dotnet-watch.Tests/Aspire/PipeUtilities.cs] Re-add the ProjectReference. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Replace the local Mocks/TestLogger.cs copy with a project reference to the shared MSTest utilities project introduced in the Aspire migration PR (dotnet#54722), keeping a single source of truth for the TestLogger implementation. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Evangelink · 2026-06-12T21:14:01Z

/azp run dotnet-sdk-public-ci

azure-pipelines · 2026-06-12T21:14:21Z