chore(deps): update dependency polyfill to 8.9.0

[thomhurst]

This PR contains the following updates:

Package	Type	Update	Change
Polyfill	nuget	minor	8.8.1 -> 8.9.0

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Release Notes

SimonCropp/Polyfill (Polyfill)

v8.9.0

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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This PR has been generated by Renovate Bot.

[claude]

Claude finished @thomhurst's task —— View job

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Pull Request Review

Reviewing this dependency update PR for:

• Code quality and best practices
• Potential bugs or issues
• Performance considerations
• Security concerns
• Test coverage

Todo List:

• Read project guidelines from CLAUDE.md
• Examine the changed file to understand the modification
• Analyze the Polyfill dependency and version update
• Provide comprehensive review feedback

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Review Summary

This PR updates the Polyfill package dependency from version 8.8.1 to 8.9.0 in the TUnit framework. Here's my analysis:

✅ Code Quality & Best Practices

• Clean change: The modification is precisely scoped to updating a single version number in TUnit.Core.targets:11
• Consistent approach: The change aligns with TUnit's dependency management strategy using MSBuild properties
• Proper automation: Renovate bot handles the update systematically

⚠️ Potential Issues Identified

Version Inconsistency: The most significant issue is that Directory.Packages.props:61 still references Polyfill version 8.8.1, while TUnit.Core.targets:11 now specifies 8.9.0. This creates a mismatch in Central Package Management (CPM) scenarios.

Root Cause: The targets file defines _TUnitPolyfillVersion for warning messages and validation, but when ManagePackageVersionsCentrally='true', the actual version comes from Directory.Packages.props. This could lead to:

• Confusing warning messages showing version 8.9.0 when 8.8.1 is actually used
• Inconsistent behavior between CPM and non-CPM projects

🔒 Security Considerations

• Low risk: Polyfill is a compile-time only dependency (PrivateAssets=all, ExcludeAssets=runtime)
• Trusted source: SimonCropp is a well-established .NET community maintainer
• Minimal surface area: Only used for compile-time type generation, not runtime execution

⚡ Performance Considerations

• Compile-time only impact: No runtime performance implications since polyfills are excluded from runtime assets
• Scope limited: Only affects .NET Standard 2.0/2.1 and .NET Framework projects based on the condition in line 12

🧪 Test Coverage

• No test changes needed: This is purely a dependency version update
• Automated validation: The existing build process will validate compatibility

📋 Recommendations

1. Critical: Update Directory.Packages.props:61 to match the version 8.9.0 to maintain consistency
2. Consider: Running the test suite to verify no breaking changes (though unlikely for a minor version bump)
3. Optional: Review the Polyfill 8.9.0 changelog for any relevant changes

🎯 Verdict

Conditionally Approve - The change itself is sound, but the version inconsistency in Directory.Packages.props should be addressed before merging to ensure consistent behavior across all project configurations.

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