[Andrew Arnott (AArnott)]

Explicitly initializing a [ThreadStatic] field to its type's default value is redundant, but it does not create inconsistent values across threads. Report these inline initializers as informational instead of warning-level diagnostics.

The analyzer now recognizes semantic default values such as null, default, numeric zero, false, and \0 for fields and auto-property backing fields. Non-default initializers and static-constructor assignments remain warnings. C# and Visual Basic tests cover both severity paths, and the VSTHRD117 documentation explains the distinction.

Validation

• dotnet test --project .\test\Microsoft.VisualStudio.Threading.Analyzers.Tests\Microsoft.VisualStudio.Threading.Analyzers.Tests.csproj -c Release -- --filter-class ThreadStaticAnalyzerTests --filter-not-trait "FailsInCloudTest=true"

[Copilot]

Pull request overview

This PR updates the VSTHRD117 analyzer so that redundant inline initializers of [ThreadStatic] fields/backing fields that assign a semantic default value are reported as Info rather than Warning, while keeping non-default inline initializers and type-initializer (static ctor) assignments at Warning severity.

Changes:

• Adjust VSTHRD117 reporting for field/property inline initializers to emit Info when the initializer is a semantic default (null, default, numeric zero, false, '\0', etc.).
• Expand C# and Visual Basic tests to validate both Info and Warning severities for inline initializers.
• Update the VSTHRD117 documentation to describe the new severity distinction and recommended fixes.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated no comments.

File	Description
test/Microsoft.VisualStudio.Threading.Analyzers.Tests/ThreadStaticAnalyzerTests.cs	Updates/expands analyzer tests to assert per-case Info vs Warning severity for inline initializers in C# and VB.
src/Microsoft.VisualStudio.Threading.Analyzers/ThreadStaticAnalyzer.cs	Implements semantic default-value recognition for inline initializers and reports VSTHRD117 as Info for default initializers.
docfx/analyzers/VSTHRD117.md	Documents the new severity behavior and clarifies the “Solution” guidance for default vs non-default initializers.

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