chore(deps): update dependency polyfill to 9.4.0

[thomhurst]

This PR contains the following updates:

Package	Type	Update	Change
Polyfill	nuget	minor	9.3.4 → 9.4.0

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Release Notes

SimonCropp/Polyfill (Polyfill)

v9.4.0

Compare Source

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Configuration

📅 Schedule: Branch creation - At any time (no schedule defined), Automerge - At any time (no schedule defined).

🚦 Automerge: Enabled.

♻ Rebasing: Whenever PR is behind base branch, or you tick the rebase/retry checkbox.

🔕 Ignore: Close this PR and you won't be reminded about this update again.

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• If you want to rebase/retry this PR, check this box

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This PR has been generated by Renovate Bot.

[claude]

PR Review: Polyfill 9.3.4 → 9.4.0

✅ Overall Assessment: APPROVED

This is a clean, low-risk dependency update that follows TUnit's conventions.

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📋 Code Quality

✅ Positive:

• Single-line change in MSBuild targets file - minimal surface area for issues
• Follows semantic versioning (minor version bump)
• Auto-generated by Renovate Bot with proper configuration
• Automerge enabled, which is appropriate for this type of update

📍 Observations:

• The change updates the Polyfill package version used for compile-time type generation on older frameworks (netstandard2.0, netstandard2.1, .NET Framework)
• No code changes required - purely a version bump

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🔍 Potential Issues

No issues identified. This is a well-isolated dependency update.

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⚡ Performance Considerations

Low impact:

• Polyfill is used at compile-time for type generation on older frameworks
• No runtime performance implications
• The dependency is conditionally applied only when targeting older frameworks

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🔒 Security Concerns

No security concerns:

• Polyfill is a well-maintained package by Simon Cropp (trusted .NET community contributor)
• Minor version updates typically contain bug fixes and feature additions without breaking changes
• No CVEs associated with the previous version

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🧪 Test Coverage

Recommendations:

• ✅ CI checks should verify the update works across all target frameworks
• ✅ Ensure existing snapshot tests pass (no source generator output changes expected)
• ✅ Verify AOT compilation still works if applicable

Since this only affects compile-time polyfills for older frameworks, the existing test suite should provide adequate coverage.

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📌 Alignment with TUnit Guidelines (CLAUDE.md)

✅ Compliant:

• No dual-mode implementation concerns (compile-time dependency only)
• No snapshot updates needed (no source generator changes)
• No VSTest references
• No performance regression risk
• No reflection/AOT concerns (compile-time only)

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💡 Recommendation

Approve and merge once CI passes. This is exactly the type of dependency update that should be automated via Renovate.

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Review conducted per TUnit development guidelines in CLAUDE.md

[Copilot]

Pull request overview

This PR updates the Polyfill dependency from version 9.3.4 to 9.4.0, a minor version bump. The update modifies the internal version reference used by TUnit.Core for automatic Polyfill package injection on older target frameworks (netstandard2.0, netstandard2.1, and .NET Framework).

• Updates the _TUnitPolyfillVersion MSBuild property from 9.3.4 to 9.4.0

[Copilot]

The Polyfill version is being updated to 9.4.0 in this file, but the version in Directory.Packages.props (line 62) is still set to 9.3.4. Both locations should be updated together to maintain version consistency across the project, especially since this project uses Central Package Management.

Suggested change

	<_TUnitPolyfillVersion>9.4.0</_TUnitPolyfillVersion>
	<_TUnitPolyfillVersion>9.3.4</_TUnitPolyfillVersion>

[claude]

Pull Request Review

Summary

This PR updates the Polyfill dependency from version 9.3.4 to 9.4.0 in the TUnit.Core.targets file.

Code Quality ✅

• Clean change: Single-line version bump, straightforward and minimal
• Scope: Appropriately limited to the version property only
• Consistency: Follows the existing MSBuild targets pattern

Best Practices ✅

• Automated dependency management: Good use of Renovate Bot for keeping dependencies current
• Centralized version management: The version is stored in a single property (_TUnitPolyfillVersion) and referenced in both CPM and non-CPM scenarios, which is excellent for maintainability

Potential Considerations

1. Testing 🔍

Since Polyfill is used for compile-time type generation in netstandard2.0, netstandard2.1, and .NET Framework targets, please verify:

• Tests pass for all affected target frameworks (netstandard2.0, netstandard2.1, .NET Framework)
• Source generator tests complete successfully (TUnit.Core.SourceGenerator.Tests)
• No snapshot updates required

Recommended verification:

# Test specifically with older frameworks that use Polyfill
dotnet build -f netstandard2.0
dotnet test --framework netstandard2.0

2. Polyfill Purpose ℹ️

The Polyfill package provides modern C# features to older target frameworks. Ensure that:

• The update doesn't introduce analyzer warnings or errors for the older TFMs
• The compile-time polyfills still work correctly with TUnit's source generators

3. Release Notes Review 📋

While the change appears to be a minor version bump, it would be beneficial to review the Polyfill 9.4.0 release notes to understand:

• What new polyfills were added (if any)
• Whether any existing polyfills were modified
• Any potential compatibility notes

Performance Considerations ✅

• No runtime impact: Polyfill is a compile-time only dependency (PrivateAssets=all, ExcludeAssets=runtime)
• No performance concerns: Version bumps to polyfill libraries typically don't affect runtime performance

Security Concerns ✅

• Low risk: Polyfill is a well-maintained Microsoft/community library by Simon Cropp
• Compile-time only: No runtime security surface since assets are excluded

Test Coverage 📊

The existing TUnit test suite should adequately cover this change, particularly:

• TUnit.Core.SourceGenerator.Tests - Tests source generation with polyfills
• Framework-specific test runs - Ensure netstandard2.0/2.1 compatibility

Recommendation

✅ APPROVE with the following conditions:

1. Verify CI/CD passes for all target frameworks
2. Confirm no snapshot test updates are needed
3. Monitor for any analyzer warnings in older TFMs

This is a routine dependency update with low risk. The automerge setting is appropriate given the minor version nature and automated testing.

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Review conducted following TUnit development guidelines from CLAUDE.md

[claude]

Pull Request Review

Summary

This PR updates the Polyfill dependency from version 9.3.4 to 9.4.0. This is a Renovate-generated dependency update.

✅ Positive Aspects

• Clean change: The update is minimal and focused (single line change)
• Non-breaking update: This is a minor version bump, reducing the risk of breaking changes
• Automated process: Using Renovate bot ensures dependencies stay current

⚠️ Issues Found

CRITICAL: Incomplete Update

The PR only updates the Polyfill version in TUnit.Core/TUnit.Core.targets but misses Directory.Packages.props:

File: Directory.Packages.props:62

<PackageVersion Include="Polyfill" Version="9.3.4" />

This needs to be updated to:

<PackageVersion Include="Polyfill" Version="9.4.0" />

Impact: Since the repository uses Central Package Management (ManagePackageVersionsCentrally), projects referencing Polyfill will still use version 9.3.4 from Directory.Packages.props. The update in TUnit.Core.targets only affects the internal _TUnitPolyfillVersion property, but projects using CPM will get the version from Directory.Packages.props instead (see line 26 of TUnit.Core.targets which uses VersionOverride).

📋 Recommendations

1. Update Directory.Packages.props to include the same version bump
2. Consider configuring Renovate to recognize both files for Polyfill updates to prevent this issue in future PRs
3. Verify CI passes after updating both files

🔍 Testing Considerations

• No new tests required (dependency update only)
• Verify existing tests pass with the new Polyfill version
• According to CLAUDE.md, no snapshot updates should be needed unless Polyfill changes affect public API or source generator output

Security & Performance

• ✅ No security concerns identified
• ✅ No performance impact expected (compile-time polyfill)
• ✅ No breaking changes expected (minor version bump)

Conclusion

Status: Requires Changes ⚠️

The PR cannot be merged in its current state. Please update Directory.Packages.props to maintain version consistency across the codebase.

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Review generated based on repository's CLAUDE.md guidelines