Avoid serialization for parameterized tests when running MTP+DisableAppDomain

[Youssef1313]

• The VSTest condition complicates some stuff, but it avoids regressions for randomized tests. We could decide to take a breaking change for randomized tests and force users to fold them. But I'm avoiding this for now.
• AppDomain check is missing currently. It's very needed as TestMethod.ActualData isn't serialized. So when we discover in an appdomain and run in another, the only way we have is serialization.

[Copilot]

Pull request overview

This PR threads an isMTP flag through MSTest discovery/execution paths so Microsoft.Testing.Platform (MTP) can alter how parameterized (data-driven) tests are handled—specifically aiming to avoid serializing unfolded ITestDataSource data when running under MTP with AppDomains disabled.

Changes:

• Add isMTP plumbing from the MTP bridge into MSTest discover/run flows.
• Pass isMTP through discovery components down to AssemblyEnumerator unfolding logic.
• Update unit/integration tests to match new method signatures.

Reviewed changes

Copilot reviewed 13 out of 13 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
test/UnitTests/MSTestAdapter.UnitTests/MSTestExecutorTests.cs	Updates executor test calls to pass isMTP: false.
test/UnitTests/MSTestAdapter.PlatformServices.UnitTests/Execution/TestExecutionManagerTests.cs	Updates execution-manager tests for the new RunTestsAsync signature including isMTP.
test/UnitTests/MSTestAdapter.PlatformServices.UnitTests/Discovery/UnitTestDiscovererTests.cs	Updates discoverer tests and overrides to accept isMTP.
test/UnitTests/MSTestAdapter.PlatformServices.UnitTests/Discovery/AssemblyEnumeratorWrapperTests.cs	Updates wrapper tests to pass the new isMTP argument.
test/UnitTests/MSTestAdapter.PlatformServices.UnitTests/Discovery/AssemblyEnumeratorTests.cs	Updates enumerator tests to call EnumerateAssembly(..., isMTP).
test/IntegrationTests/MSTest.IntegrationTests/Utilities/CLITestBase.discovery.cs	Updates integration discovery helper to pass isMTP: false.
src/Adapter/MSTestAdapter.PlatformServices/Execution/TestExecutionManager.cs	Adds isMTP parameter to source-based run path and forwards it into discovery; also introduces an (unused) IsMicrosoftTestingPlatform property.
src/Adapter/MSTestAdapter.PlatformServices/Discovery/UnitTestDiscoverer.cs	Adds isMTP parameter and forwards it to AssemblyEnumeratorWrapper.
src/Adapter/MSTestAdapter.PlatformServices/Discovery/AssemblyEnumeratorWrapper.cs	Adds isMTP parameter and forwards it to AssemblyEnumerator.EnumerateAssembly.
src/Adapter/MSTestAdapter.PlatformServices/Discovery/AssemblyEnumerator.cs	Adds isMTP to unfolding pipeline and conditionally skips SerializedData generation for ITestDataSource rows.
src/Adapter/MSTest.TestAdapter/VSTestAdapter/MSTestExecutor.cs	Extends internal RunTestsAsync(sources, ...) to accept isMTP and pass through to TestExecutionManager.
src/Adapter/MSTest.TestAdapter/VSTestAdapter/MSTestDiscoverer.cs	Extends internal DiscoverTests to accept isMTP and pass through to UnitTestDiscoverer.
src/Adapter/MSTest.TestAdapter/TestingPlatformAdapter/MSTestBridgedTestFramework.cs	Calls adapter discover/run with isMTP: true when invoked from MTP.

[Copilot]

Pull request overview

Copilot reviewed 14 out of 14 changed files in this pull request and generated 1 comment.

[Copilot]

Pull request overview

Copilot reviewed 15 out of 15 changed files in this pull request and generated 1 comment.

Comments suppressed due to low confidence (1)

src/Adapter/MSTestAdapter.PlatformServices/Discovery/AssemblyEnumerator.cs:337

• The new mustSerialize behavior (skipping DataSerializationHelper.Serialize when false) isn't covered by unit tests. Please add tests that exercise both paths (mustSerialize=true and mustSerialize=false) for ITestDataSource unfolding to ensure SerializedData is populated when required (AppDomain/serialization scenarios) and that execution can rely on ActualData when serialization is skipped.

                if (mustSerialize)
                {
                    discoveredTest.TestMethod.SerializedData = DataSerializationHelper.Serialize(d);
                }

                discoveredTest.TestMethod.ActualData = d;
                discoveredTest.TestMethod.TestCaseIndex = globalTestCaseIndex;
                discoveredTest.TestMethod.TestDataSourceIgnoreMessage = testDataSourceIgnoreMessage;
                discoveredTest.TestMethod.DataType = DynamicDataType.ITestDataSource;

[Copilot]

mustSerialize is now computed from isMTP and whether the isolation host uses AppDomains, but there are no tests covering this decision logic. Adding a targeted unit test (e.g., validating that when isMTP=true and AppDomains are disabled, discovery avoids serialization, and when AppDomains are enabled it still serializes) would help prevent regressions in the MTP + DisableAppDomain scenario this change is addressing.