[ResourceLock] Replace class-level DoNotParallelize with ResourceLock(Console) in TerminalOutputDeviceTests

[nohwnd-bot]

gh-aw-workflow-id: resource-lock-refactoring

Summary

Replaces the class-level [DoNotParallelize] on TerminalOutputDeviceTests
(test/UnitTests/Microsoft.Testing.Platform.UnitTests/OutputDevice/TerminalOutputDeviceTests.cs)
with [ResourceLock(WellKnownResources.Console)].

Project and current scope: Microsoft.Testing.Platform.UnitTests already
declares [assembly: Parallelize(Scope = ExecutionScope.MethodLevel, Workers = 0)]
in Program.cs, so this project is already parallelized at the method level.
TerminalOutputDeviceTests was one of the few classes still opting out entirely
via a class-level [DoNotParallelize].

Shared resource and conflicting tests: every test method in the class
temporarily redirects the process-global Console.Error stream
(Console.SetError(...)) to capture output, then restores the original writer
in a finally block. Six methods in the class do this
(AssertListTestsJsonStandardErrorAsync / CaptureListTestsJsonStandardErrorAsync
and InitializeAndCaptureStandardErrorAsync, used by 8+ [TestMethod]s). Since
Console.Error is process-global, two tests in this class running concurrently
under MethodLevel parallelization could redirect/restore the stream out of
order and corrupt each other's captured output. The class previously guarded
this with a hand-rolled SemaphoreSlim ConsoleErrorSemaphore plus
[DoNotParallelize] at the class level — a strictly broader mechanism than
needed, since it serializes the whole class rather than just the
Console.Error critical sections.

Why this attribute placement is minimal: [ResourceLock(WellKnownResources.Console)]
at the class level lets the MSTest engine serialize only tests contending on the
same declared resource (System.Console), instead of forcing full sequential
execution of the class via [DoNotParallelize]. This is the narrowest
class-level fix because every test method in the class touches Console.Error,
so a method-level placement would be equivalent but more verbose; there is no
test in the class that doesn't need the lock. The now-redundant
ConsoleErrorSemaphore field and its WaitAsync/Release calls were removed
since [ResourceLock] already provides the serialization guarantee at the
MSTest engine level.

No assembly-level Parallelize/DoNotParallelize attributes, .runsettings,
or testconfig.json parallelization settings were touched.

Validation

• bash ./build.sh — build succeeded (0 errors, 0 warnings).
• PATH="$PWD/.dotnet:$PATH" dotnet run --project test/UnitTests/Microsoft.Testing.Platform.UnitTests -f net9.0 --no-build -c Debug -- --filter "FullyQualifiedName~TerminalOutputDeviceTests" — 10/10 tests passed under the assembly's actual MethodLevel parallel scheduling (Test Parallelization enabled ... Workers: 4, Scope: MethodLevel).
• Acceptance/integration validation (./build.sh -pack) was not run: this change only touches a unit-test project and does not affect any acceptance test asset or packed artifact.

Workflow run: https://github.com/microsoft/testfx/actions/runs/33050722434

DOTNET_CLI_TELEMETRY_SESSIONID used during validation: gha-65080725-33050722434-1.

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Automated by the ResourceLock refactoring workflow. · auto · 166.6 AIC · ⌖ 2.98 AIC · ⊞ 11.1K | [History]( · ◷)

[Copilot]

Pull request overview

Replaces broad test-class serialization with resource-specific locking for process-global console access.

Changes:

• Adds [ResourceLock(WellKnownResources.Console)].
• Removes the redundant SemaphoreSlim and manual lock handling.

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