Migrate Microsoft.AspNetCore.Watch.BrowserRefresh.Tests to MSTest.Sdk on MTP by Evangelink · Pull Request #54725 · dotnet/sdk

Evangelink · 2026-06-11T19:35:25Z

Same pattern as #54723 / #54724. None of the 6 test files use any Microsoft.NET.TestFramework types — only xUnit primitives — so the TestFramework ProjectReference can be dropped and the project switched to MSTest.Sdk in one self-contained change.

Changes

csproj: Sdk="MSTest.Sdk", UseMSTestSdk=true, drop TestFramework ref + OutputType=Exe, add Microsoft.VisualStudio.TestTools.UnitTesting using.
6 test files: xUnit → MSTest mechanical conversion plus targeted fixes:
- [Fact]/[Theory] → [TestMethod], [InlineData] → [DataRow], add [TestClass].
- Assert.True/False/Null/NotNull/Empty/NotEmpty/Equal/NotEqual → IsTrue/IsFalse/IsNull/IsNotNull/IsEmpty/IsNotEmpty/AreEqual/AreNotEqual.
- Assert.Single(x) → Assert.HasCount(1, x).
- String Assert.Contains(needle, haystack) → StringAssert.Contains(haystack, needle) (xUnit and MSTest argument orders are reversed).
- One Assert.DoesNotContain(needle, str) → Assert.IsFalse(str.Contains(needle)).
- Assert.Collection in BrowserScriptMiddlewareTest expanded to inline Assert.HasCount + indexed AreEqual checks.
- Assert.ThrowsAsync<T> → Assert.ThrowsExactlyAsync<T>.
- Assert.AreEqual on byte[]/int[] → Assert.AreSequenceEqual (MSTEST0065: MSTest does not do element-wise equality on collections; the analyzer catches a real semantic difference vs xUnit).
- StringValues (Microsoft.Extensions.Primitives) ambiguity with Assert.AreEqual<T> resolved by calling .ToString() at 5 call sites.
- xUnit v3 TestContext.Current.CancellationToken → CancellationToken.None (MSTest's TestContext.Current is experimental; these unit tests do not actually require test-cancellation propagation).

Verification

✅ 110/110 tests pass on MTP (~480 ms).

Merge ordering

Stacks on #54724 which stacks on #54723 which stacks on #54722.

Relates to #52914.

tmat

Why are we migrating away from XUnit?

Copilot

Pull request overview

Migrates additional SDK test projects from xUnit to MSTest.Sdk (on Microsoft.Testing.Platform), dropping the xUnit-coupled Microsoft.NET.TestFramework where it isn’t needed and updating assertions/attributes accordingly.

Changes:

Add MSTest.Sdk to global.json and gate the repo’s xUnit-specific test defaults behind UseMSTestSdk.
Convert several unit test projects (notably Microsoft.AspNetCore.Watch.BrowserRefresh.Tests) to MSTest attributes/asserts and remove the TestFramework ProjectReference.
Update dotnet-watch.Tests to support Aspire integration tests (new helper + project reference + IVT).

Show a summary per file

File	Description
global.json	Adds `MSTest.Sdk` msbuild SDK version pin.
test/Directory.Build.targets	Gates xUnit defaults behind `UseMSTestSdk` opt-out.
test/containerize.UnitTests/containerize.UnitTests.csproj	Switches project to `MSTest.Sdk`, removes TestFramework reference.
test/containerize.UnitTests/ParserTests.cs	Converts xUnit tests to MSTest attributes/asserts.
test/Microsoft.DotNet.ApiCompat.Tests/Microsoft.DotNet.ApiCompat.Tests.csproj	Switches project to `MSTest.Sdk`, removes TestFramework reference, adds MSTest global using.
test/Microsoft.DotNet.ApiCompat.Tests/RegexStringTransformerTests.cs	Converts xUnit tests to MSTest attributes/asserts.
test/Microsoft.DotNet.HotReload.Watch.Aspire.Tests/Microsoft.DotNet.HotReload.Watch.Aspire.Tests.csproj	Switches project to `MSTest.Sdk`, removes xUnit-coupled test utilities reference.
test/Microsoft.DotNet.HotReload.Watch.Aspire.Tests/AssertEx.cs	Adds a small local assertion helper to avoid TestFramework dependency.
test/Microsoft.DotNet.HotReload.Watch.Aspire.Tests/AspireServerLauncherCliTests.cs	Converts xUnit tests to MSTest attributes/asserts.
test/Microsoft.DotNet.HotReload.Watch.Aspire.Tests/AspireResourceLauncherCliTests.cs	Converts xUnit tests to MSTest attributes/asserts (incl. DataRow conversions).
test/Microsoft.DotNet.HotReload.Watch.Aspire.Tests/AspireHostLauncherTests.cs	Converts xUnit tests to MSTest attributes/asserts.
test/Microsoft.DotNet.HotReload.Watch.Aspire.Tests/AspireHostLauncherCliTests.cs	Converts xUnit tests to MSTest attributes/asserts.
src/Dotnet.Watch/Watch.Aspire/Properties/AssemblyInfo.cs	Adds `InternalsVisibleTo` for `dotnet-watch.Tests`.
test/dotnet-watch.Tests/dotnet-watch.Tests.csproj	Adds `Watch.Aspire` project reference needed by Aspire integration tests.
test/dotnet-watch.Tests/Aspire/AspireLauncherIntegrationTests.cs	Renames integration test class for clarity.
test/dotnet-watch.Tests/Aspire/PipeUtilities.cs	Adds new helper for reading Aspire status events via named pipes.
test/Microsoft.AspNetCore.Watch.BrowserRefresh.Tests/Microsoft.AspNetCore.Watch.BrowserRefresh.Tests.csproj	Switches BrowserRefresh test project to `MSTest.Sdk`, removes TestFramework reference.
test/Microsoft.AspNetCore.Watch.BrowserRefresh.Tests/ScriptInjectingStreamTests.cs	Converts xUnit tests to MSTest attributes/asserts and adjusts cancellation handling.
test/Microsoft.AspNetCore.Watch.BrowserRefresh.Tests/ResponseStreamWrapperCompressionTest.cs	Converts xUnit tests to MSTest attributes/asserts and string/sequence asserts.
test/Microsoft.AspNetCore.Watch.BrowserRefresh.Tests/HostingStartupTest.cs	Converts xUnit tests to MSTest attributes/asserts and resolves `StringValues` comparisons.
test/Microsoft.AspNetCore.Watch.BrowserRefresh.Tests/BrowserScriptMiddlewareTest.cs	Converts xUnit tests to MSTest attributes/asserts and expands `Assert.Collection`.
test/Microsoft.AspNetCore.Watch.BrowserRefresh.Tests/BrowserRefreshMiddlewareTest.cs	Converts xUnit tests to MSTest attributes/asserts and updates string containment checks.
test/Microsoft.AspNetCore.Watch.BrowserRefresh.Tests/BlazorWasmHotReloadMiddlewareTest.cs	Converts xUnit tests to MSTest attributes/asserts and sequence comparisons.

Copilot's findings

Files reviewed: 22/23 changed files
Comments generated: 1

Evangelink · 2026-06-11T20:21:45Z

Re-validated this PR against the new migrate-xunit-to-mstest skill landed in #54727 and bumped MSTest.Sdk to 4.3.0-preview.26311.10 (latest internal preview) via the pathfinder.

Changes applied in the latest push on this branch:
StringAssert.Contains(haystack, needle) -> Assert.Contains(needle, haystack) -- uses MSTest 3.8+/4.3 overload with the natural xUnit-style (needle, haystack) order; Assert.IsFalse(str.Contains(x)) -> Assert.DoesNotContain(x, str). 12+ string assertion sites cleaned up.

Other gotchas reviewed (no changes needed here):

Assert.AreEqual argument order — verified (expected, actual) throughout, matching the xUnit Assert.Equal(expected, actual) original.
CollectionAssert argument order — verified.
Assert.ThrowsExactly<T> vs Assert.Throws<T> semantics — verified (xUnit Throws<T> is exact; MSTest's same-named API is inclusive, so the migration uses ThrowsExactly<T>).
IsInstanceOfType<T> vs IsExactInstanceOfType<T> — see dotnet/skills#755 for the cheatsheet update we filed upstream.

Tests still pass locally on the bumped MSTest.Sdk.

Imports the migrate-xunit-to-mstest skill from dotnet/skills@main (plugins/dotnet-test/skills/migrate-xunit-to-mstest) into this repo so the xUnit -> MSTest migration that's currently in progress (#54722, #54723, #54724, #54725, #54726) has a documented, repeatable procedure that contributors and agents can follow consistently. Files added (verbatim from upstream): - .github/skills/migrate-xunit-to-mstest/SKILL.md - .github/skills/migrate-xunit-to-mstest/references/mapping-cheatsheet.md Note: SKILL.md is 546 lines, slightly above the 500-line "Progressive Disclosure" guideline checked by .github/skills/ValidateSkill.cs. The validator is advisory (not CI-enforced) and we are intentionally mirroring the upstream content verbatim to keep future syncs trivial. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Evangelink · 2026-06-12T11:31:01Z

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 · 2026-06-12T11:37:50Z

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 · 2026-06-12T11:37:53Z

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 · 2026-06-12T11:55:08Z

Also removed <IsPackable>false</IsPackable> from the migrated csproj — MSTest.Sdk's Runner/Common.targets already sets it, so the per-project declaration is redundant.

Evangelink · 2026-06-12T12:08:04Z

Switched migration-introduced CancellationToken.None back to a cancellable token by adding the standard MSTest public TestContext TestContext { get; set; } property on the test class and using TestContext.CancellationToken — this preserves the original xUnit v3 behavior (TestContext.Current.CancellationToken) and keeps tests cancellable. The TestContext.Current static would also work but is currently marked experimental (MSTESTEXP).

Evangelink · 2026-06-12T12:09:47Z

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.

…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>

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Evangelink · 2026-06-16T20:32:42Z

Done — updated to assert on actualUpdate.Deltas.Length.

…EST0049) Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

…tionTests) PR dotnet#54766 enabled the Recommended MSTest analyzers as errors; dotnet#54758 merged shortly after with violations that are now build errors, leaving main red and blocking all open migration PRs. Fix the two affected files: - CommandResultAssertions.MSTest.cs: MSTEST0037 (IsTrue(a==b)->AreEqual, IsFalse(a==b) ->AreNotEqual) and MSTEST0023 (IsTrue(!x)->IsFalse(x)). - LocalizeTemplateTests.cs: MSTEST0037 (AreEqual(n, x.Length)->HasCount(n, x)). Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> (cherry picked from commit 6ac4ef0)

…fresh PR Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Evangelink · 2026-06-17T12:17:03Z

/ba-g #54813 #54818

The CI failures on this PR are not related to its changes. This PR migrates Microsoft.AspNetCore.Watch.BrowserRefresh.Tests to MSTest.Sdk/MTP; that project passed on every leg. All 3 failed Helix work items are in unrelated xUnit projects, which do not consume MSTest.Sdk and so cannot be affected by this PR's global.json MSTest.Sdk bump or the migrated test helpers:

dotnet.Tests.dll.13 → RunFileTests_BuildCommands.Pack_CustomPath — known flaky Flaky: RunFileTests_* (file-based program build) intermittently fail with MSB4025 'project file could not be loaded' #54813
Microsoft.NET.Publish.Tests.dll.4 (linux x64) and .dll.2 (macOS arm64) → GivenThatWeWantToPublishReadyToRun.It_supports_crossos_arch_compilation, "Catastrophic failure: Test process crashed with exit code 0" — known flaky Flaky: Publish ReadyToRun It_supports_crossos_arch_compilation crashes test process (exit code 0) #54818

Evangelink · 2026-06-17T12:17:14Z

/azp run dotnet-sdk-public-ci

azure-pipelines · 2026-06-17T12:17:26Z

Azure Pipelines successfully started running 1 pipeline(s).

The four 2-arg WriteAsync calls originally flowed TestContext.Current.CancellationToken in the xUnit source; restore the test cancellation token via the MSTest TestContext property rather than weakening it to CancellationToken.None. The two 3-arg calls already used CancellationToken.None on main and are left unchanged. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Evangelink · 2026-06-17T15:36:42Z

/ba-g #54826

I have closed previous tickets as they were wrongly/partially filled

Evangelink · 2026-06-17T17:43:45Z

@tmat would you reviewing/approving PR?

Evangelink · 2026-06-17T18:03:44Z

/azp run dotnet-sdk-public-ci

azure-pipelines · 2026-06-17T18:04:00Z

Azure Pipelines successfully started running 1 pipeline(s).

Evangelink · 2026-06-20T10:10:14Z

/ba-g #54819

Copilot AI review requested due to automatic review settings June 11, 2026 19:35

Evangelink requested review from a team and tmat as code owners June 11, 2026 19:35

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Comment thread test/Microsoft.AspNetCore.Watch.BrowserRefresh.Tests/BlazorWasmHotReloadMiddlewareTest.cs

Evangelink mentioned this pull request Jun 11, 2026

Migrate Microsoft.DotNet.GenAPI.Tests to MSTest.Sdk on MTP #54726

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Comment thread test/containerize.UnitTests/containerize.UnitTests.csproj Outdated

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Evangelink marked this pull request as draft June 11, 2026 19:52

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Add migrate-xunit-to-mstest skill from dotnet/skills #54727

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Evangelink force-pushed the evangelink/mstest-mtp-browserrefresh-tests branch from 3f1079f to 77b601f Compare June 11, 2026 20:18

Evangelink force-pushed the evangelink/mstest-mtp-browserrefresh-tests branch 2 times, most recently from c1a2f7f to 6835289 Compare June 11, 2026 21:04

Evangelink mentioned this pull request Jun 12, 2026

migrate-xunit-to-mstest: forbid CancellationToken.None replacement explicitly dotnet/skills#758

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Consider adding Assert.Collection(items, params Action<T>[] elementInspectors) microsoft/testfx#9079

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Fix MSTest analyzer violations breaking main #54807

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Fix MSTest analyzer violations and address review feedback

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Pass TestContext.CancellationToken to remaining WriteAsync calls (MST…

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…EST0049) Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

build-analysis Bot mentioned this pull request Jun 16, 2026

Unable to read data from the transport connection: An existing connection was forcibly closed by the remote host. dotnet/dnceng#5922

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Evangelink and others added 2 commits June 17, 2026 09:10

Propagate containerize + Aspire analyzer fixes into stacked browserre…

20dfe42

…fresh PR Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Evangelink enabled auto-merge (squash) June 17, 2026 11:13

Evangelink mentioned this pull request Jun 17, 2026

NavMenu.razor(1,5): error RZ10007: The attribute 'class' is used two or more times for this element. Attributes must be unique (case-insensitive) #54826

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build-analysis Bot mentioned this pull request Jun 18, 2026

Run-file tests failing with "The project file could not be loaded." #54819

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Apply suggestion from @Evangelink

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Merge branch 'main' into evangelink/mstest-mtp-browserrefresh-tests

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Evangelink merged commit 6dc369e into dotnet:main Jun 22, 2026
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Evangelink deleted the evangelink/mstest-mtp-browserrefresh-tests branch June 22, 2026 16:41

dotnet-maestro Bot mentioned this pull request Jun 23, 2026

[main] Source code updates from dotnet/sdk dotnet/dotnet#7335

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MichaelSimons mentioned this pull request Jun 24, 2026

Disable in-process parallel test execution #54967

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