Remove duplicate IsTypeReachableFromGeneratedCode in TestClassModelBuilder

[Copilot]

TestClassModelBuilder.IsTypeReachableFromGeneratedCode was a semantic duplicate of SymbolAccessibilityHelper.IsAccessibleFromGeneratedCode, which is already linked into the same project and used by the sibling MSTestReflectionMetadataGenerator.

Changes

• Deleted IsTypeReachableFromGeneratedCode from TestClassModelBuilder.cs
• Replaced its single call site with SymbolAccessibilityHelper.IsAccessibleFromGeneratedCode

No project file changes needed — SymbolAccessibilityHelper.cs is already referenced via <Compile Include="..\Shared\SymbolAccessibilityHelper.cs" /> and using MSTest.Analyzers.Shared; was already present.

The two implementations were semantically equivalent across all Accessibility values; they differed only in allow-list vs. deny-list style. The shared helper is the canonical version and explicitly handles NotApplicable (which the duplicate only allowed implicitly).

[Copilot]

Pull request overview

This PR removes a duplicated accessibility check in the AOT reflection source generator by replacing TestClassModelBuilder.IsTypeReachableFromGeneratedCode with the shared SymbolAccessibilityHelper.IsAccessibleFromGeneratedCode, aligning this generator with the existing pattern used by MSTestReflectionMetadataGenerator.

Changes:

• Deleted the local IsTypeReachableFromGeneratedCode helper from TestClassModelBuilder.
• Replaced the single call site with SymbolAccessibilityHelper.IsAccessibleFromGeneratedCode(current).

Show a summary per file

File	Description
src/Analyzers/MSTest.AotReflection.SourceGeneration/Generators/TestClassModelBuilder.cs	Replaces a duplicated reachability/accessibility helper with the shared SymbolAccessibilityHelper implementation.

Review details

• Files reviewed: 1/1 changed files
• Comments generated: 0
• Review effort level: Low

[Evangelink]

Note

🤖 Automated review by GitHub Copilot. Posted via a maintainer's GitHub token, so it appears under their account — the account owner did not write or approve this content personally. Generated by the Expert Code Review workflow. To request a follow-up action, reply by tagging @copilot directly.

✅ 22/22 dimensions clean — no findings.

Semantic equivalence verified. The removed IsTypeReachableFromGeneratedCode and the replacement SymbolAccessibilityHelper.IsAccessibleFromGeneratedCode produce identical results for all currently-defined Roslyn Accessibility values:

Value	Old deny-list	New allow-list
Public	✅ (falls through)	✅ (explicit continue)
Internal	✅ (falls through)	✅ (explicit continue)
ProtectedOrInternal	✅ (falls through)	✅ (explicit continue)
NotApplicable	✅ (falls through)	✅ (explicit continue)
Private	❌ (explicit return false)	❌ (default: return false)
Protected	❌ (explicit return false)	❌ (default: return false)
ProtectedAndInternal	❌ (explicit return false)	❌ (default: return false)

The allow-list style in the shared helper is marginally more defensive — any hypothetical future Roslyn Accessibility value would be denied by default rather than accidentally allowed, which is the correct conservative behaviour for a generated-code reachability guard.

Additional observations:

• The using MSTest.Analyzers.Shared; directive was already present on line 8, so no import was needed.
• SymbolAccessibilityHelper.IsAccessibleFromGeneratedCode is already exercised by MSTestReflectionMetadataGenerator and ReflectionMetadataGenerator, giving indirect test coverage of the shared path.
• No test changes are needed — this is a purely mechanical deduplication with no behavioral delta; the existing test suite validates the shared helper via the sibling generators.
• Scope is single-concern and tight: 1 addition, 24 deletions, one file.