[Andrew Arnott (AArnott)]

Summary

• add VSTHRD116 to report ThreadStaticAttribute on non-static fields and auto-property backing fields
• add VSTHRD117 to report inline initialization of thread-static fields and auto-property backing fields
• support C# and Visual Basic from one symbol/operation analyzer, with localized descriptors and published help pages
• document the overlap with .NET SDK rules CA2259 and CA2019; no code fixes are offered because the safe correction depends on intended state and initialization semantics

Validation

• focused VSTHRD116/VSTHRD117 tests across net8.0, net8.0-windows, and net472
• full analyzer test project: 1,509 passed, 33 skipped
• full Release solution build
• analyzer NuGet pack inspection for both analyzers/cs and analyzers/vb

Closes #594
Closes #595

[Copilot]

Pull request overview

Adds two new analyzers to improve correctness around ThreadStaticAttribute usage (VSTHRD116/VSTHRD117), covering both C# and Visual Basic, and publishes accompanying documentation and tests as part of the existing analyzer suite.

Changes:

• Introduces VSTHRD116ThreadStaticAnalyzer to flag ThreadStaticAttribute on non-static fields (including auto-property backing fields via [field: ...]).
• Adds VSTHRD117 diagnostics to flag inline initialization of thread-static fields/backing fields via operation analysis.
• Adds localized strings plus DocFX/GitHub Pages documentation and a new test suite validating both rules for C# and VB.

Reviewed changes

Copilot reviewed 10 out of 10 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
test/Microsoft.VisualStudio.Threading.Analyzers.Tests/VSTHRD116ThreadStaticAnalyzerTests.cs	Adds coverage for VSTHRD116/VSTHRD117 across C# and VB scenarios.
src/Microsoft.VisualStudio.Threading.Analyzers/VSTHRD116ThreadStaticAnalyzer.cs	Implements the new analyzer and both diagnostics (non-static + inline initialization).
src/Microsoft.VisualStudio.Threading.Analyzers/Types.cs	Adds Types.ThreadStaticAttribute.FullName for reliable metadata lookup.
src/Microsoft.VisualStudio.Threading.Analyzers/Strings.resx	Adds localized titles/messages for VSTHRD116 and VSTHRD117.
docfx/analyzers/VSTHRD116.md	Adds DocFX help page for the new VSTHRD116 rule.
docfx/analyzers/VSTHRD117.md	Adds DocFX help page for the new VSTHRD117 rule.
docfx/analyzers/toc.yml	Registers the new analyzer docs in the DocFX TOC.
docfx/analyzers/index.md	Adds the new rules to the analyzer index table.
doc/analyzers/VSTHRD116.md	Adds redirect stub to GitHub Pages for VSTHRD116.
doc/analyzers/VSTHRD117.md	Adds redirect stub to GitHub Pages for VSTHRD117.

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[Copilot]

Pull request overview

Copilot reviewed 8 out of 8 changed files in this pull request and generated no new comments.

[Copilot]

Pull request overview

Copilot reviewed 8 out of 8 changed files in this pull request and generated no new comments.

[Copilot]

Pull request overview

Copilot reviewed 8 out of 8 changed files in this pull request and generated no new comments.

Suppressed comments (1)

Previously missed (1) — in code that hasn't changed since the last review.

test/Microsoft.VisualStudio.Threading.Analyzers.Tests/ThreadStaticAnalyzerTests.cs:177

• Visual Basic tests cover fields, but there are no tests exercising the analyzer’s support for auto-property backing fields (e.g., <Field: ThreadStatic> on an auto-implemented Property, and the Property initializer case). Since the analyzer explicitly handles SymbolKind.Property and OperationKind.PropertyInitializer, adding VB auto-property tests would help prevent regressions and validate the intended cross-language behavior.

    [Fact]
    public async Task NonStaticFields_VisualBasic()
    {
        const string test = """
            Imports System

            Class Test
                <ThreadStatic>
                Private {|VSTHRD116:first|} As Object

                <Global.System.ThreadStaticAttribute>
                Private {|VSTHRD116:second|}, {|VSTHRD116:third|} As Integer

            End Class
            """;

        await VBVerify.VerifyAnalyzerAsync(test);
    }

[Copilot]

Pull request overview

Copilot reviewed 8 out of 8 changed files in this pull request and generated no new comments.

Suppressed comments (2)

Previously missed (2) — in code that hasn't changed since the last review.

src/Microsoft.VisualStudio.Threading.Analyzers/ThreadStaticAnalyzer.cs:16

• Consider renaming this analyzer type to match the established naming convention in this project where DiagnosticAnalyzer implementations are prefixed with their primary diagnostic ID (e.g. VSTHRD115AvoidJoinableTaskContextCtorWithNullArgsAnalyzer, VSTHRD111UseConfigureAwaitAnalyzer). This makes analyzers easier to discover/grep when triaging diagnostics.

public class ThreadStaticAnalyzer : DiagnosticAnalyzer

test/Microsoft.VisualStudio.Threading.Analyzers.Tests/ThreadStaticAnalyzerTests.cs:7

• To align with the existing test naming pattern in this project (most analyzer test classes start with the diagnostic ID, e.g. VSTHRD115AvoidJoinableTaskContextCtorWithNullArgTests), consider prefixing this test class name with the primary ID it covers.

public class ThreadStaticAnalyzerTests

[Copilot]

Pull request overview

Copilot reviewed 8 out of 8 changed files in this pull request and generated no new comments.