Add code fix for MSTEST0031 — DoNotUseSystemDescriptionAttribute

[Copilot]

MSTEST0031 warns when [System.ComponentModel.Description("...")] is applied to a test method, but provided no automated fix. This adds a code fixer that replaces the System.ComponentModel.DescriptionAttribute with MSTest's own DescriptionAttribute, using Roslyn's Simplifier to produce the correct name form based on the current using directives.

Fix behavior

• Replaces [System.ComponentModel.Description("text")] (or [Description("text")] bound to System.ComponentModel) with MSTest's [Description("text")] (Microsoft.VisualStudio.TestTools.UnitTesting.DescriptionAttribute)
• Uses Simplifier.ReduceAsync with the fully-qualified Microsoft.VisualStudio.TestTools.UnitTesting.DescriptionAttribute name so the output is always correct:
  • Simplified to [Description("text")] when the MSTest namespace is unambiguously in scope
  • Kept fully-qualified as [Microsoft.VisualStudio.TestTools.UnitTesting.DescriptionAttribute("text")] when using System.ComponentModel is also present (ambiguous) or when no namespace is imported

Before / After (typical case):

// Before
[TestMethod]
[System.ComponentModel.Description("My test description")]
public void MyTest() { }

// After
[TestMethod]
[Description("My test description")]
public void MyTest() { }

Before / After (with using System.ComponentModel also imported):

// Before
[TestMethod]
[Description("My test description")]  // binds to System.ComponentModel.DescriptionAttribute
public void MyTest() { }

// After
[TestMethod]
[Microsoft.VisualStudio.TestTools.UnitTesting.DescriptionAttribute("My test description")]
public void MyTest() { }

Changes

• DoNotUseSystemDescriptionAttributeFixer.cs — new fixer using the semantic model to identify the System.ComponentModel.DescriptionAttribute, replaces its name with the fully-qualified MSTest DescriptionAttribute annotated with Simplifier.Annotation, then calls Simplifier.ReduceAsync to produce the minimal unambiguous form
• CodeFixResources.resx — adds UseMSTestDescriptionAttributeInsteadFix title string
• DoNotUseSystemDescriptionAttributeAnalyzerTests.cs — switches from EmptyCodeFixProvider to the new fixer; adds code-fix tests covering the standard case, the using System.ComponentModel ambiguity case, and the fully-qualified (no using) case

[Evangelink]

@copilot that seems wrong, we should instead use MSTest DescriptionAttribute

[Copilot]

@copilot that seems wrong, we should instead use MSTest DescriptionAttribute

Updated in aace8a7. The fixer now replaces [System.ComponentModel.Description("text")] with MSTest's own [Description("text")] (Microsoft.VisualStudio.TestTools.UnitTesting.DescriptionAttribute) by simply renaming the attribute name to the simple identifier Description, which resolves to MSTest's attribute since the MSTest namespace is already in scope.

[github-actions]

Summary

Workflow: Test Expert Reviewer 🧪
Date: 2026-04-28
Repository: microsoft/testfx

Key Findings

1. [Coverage] Missing edge case: shortened attribute form with using System.ComponentModel;
   The added code-fix test covers only the fully-qualified [System.ComponentModel.Description("...")] syntax. The analyzer (which uses semantic analysis) would also trigger on the shortened [Description("...")] form when using System.ComponentModel; is in scope. In that scenario, the fixer's current implementation — unconditionally replacing the attribute name with the simple identifier Description — could produce ambiguous code that won't compile, because both System.ComponentModel.DescriptionAttribute and Microsoft.VisualStudio.TestTools.UnitTesting.DescriptionAttribute would be in scope. A test case covering this form is needed to surface and protect against that behavior.

What's Good

• The test follows the repo's established pattern (CSharpCodeFixVerifier<TAnalyzer, TFixer> alias, VerifyCodeFixAsync) perfectly.
• Roslyn inline diagnostic markup ([|MyTestMethod|]) is used correctly.
• The no-diagnostic path (WhenMethodWithoutTestMethodAttribute_HasSystemDescriptionAttribute_NoDiagnostic) is retained and correct.
• No isolation or flakiness concerns — all tests run in-memory via the Roslyn testing framework.

Recommendations

• Add a test case for the shortened [Description("text")] form when using System.ComponentModel; is present. This will reveal whether the fixer needs to also remove (or adjust) the conflicting using directive to produce valid code.

---

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🧪 Test quality reviewed by Test Expert Reviewer 🧪

[Copilot]

Pull request overview

Adds a C# code fix for MSTEST0031 (“DoNotUseSystemDescriptionAttribute”) so users can automatically replace System.ComponentModel.DescriptionAttribute on test methods with MSTest’s DescriptionAttribute, along with the necessary localized UI strings and a verifier update.

Changes:

• Introduces DoNotUseSystemDescriptionAttributeFixer code fix provider.
• Adds the new code fix title to CodeFixResources.resx and propagates it to localized *.xlf files.
• Updates the analyzer unit test to validate the code fix result.

Show a summary per file

File	Description
test/UnitTests/MSTest.Analyzers.UnitTests/DoNotUseSystemDescriptionAttributeAnalyzerTests.cs	Switches to the real code fix provider and adds a code-fix verification.
src/Analyzers/MSTest.Analyzers.CodeFixes/DoNotUseSystemDescriptionAttributeFixer.cs	New fixer that rewrites the attribute name for MSTEST0031.
src/Analyzers/MSTest.Analyzers.CodeFixes/CodeFixResources.resx	Adds the code-fix title string.
src/Analyzers/MSTest.Analyzers.CodeFixes/xlf/CodeFixResources.cs.xlf	Adds localized entry for the new code-fix title.
src/Analyzers/MSTest.Analyzers.CodeFixes/xlf/CodeFixResources.de.xlf	Adds localized entry for the new code-fix title.
src/Analyzers/MSTest.Analyzers.CodeFixes/xlf/CodeFixResources.es.xlf	Adds localized entry for the new code-fix title.
src/Analyzers/MSTest.Analyzers.CodeFixes/xlf/CodeFixResources.fr.xlf	Adds localized entry for the new code-fix title.
src/Analyzers/MSTest.Analyzers.CodeFixes/xlf/CodeFixResources.it.xlf	Adds localized entry for the new code-fix title.
src/Analyzers/MSTest.Analyzers.CodeFixes/xlf/CodeFixResources.ja.xlf	Adds localized entry for the new code-fix title.
src/Analyzers/MSTest.Analyzers.CodeFixes/xlf/CodeFixResources.ko.xlf	Adds localized entry for the new code-fix title.
src/Analyzers/MSTest.Analyzers.CodeFixes/xlf/CodeFixResources.pl.xlf	Adds localized entry for the new code-fix title.
src/Analyzers/MSTest.Analyzers.CodeFixes/xlf/CodeFixResources.pt-BR.xlf	Adds localized entry for the new code-fix title.
src/Analyzers/MSTest.Analyzers.CodeFixes/xlf/CodeFixResources.ru.xlf	Adds localized entry for the new code-fix title.
src/Analyzers/MSTest.Analyzers.CodeFixes/xlf/CodeFixResources.tr.xlf	Adds localized entry for the new code-fix title.
src/Analyzers/MSTest.Analyzers.CodeFixes/xlf/CodeFixResources.zh-Hans.xlf	Adds localized entry for the new code-fix title.
src/Analyzers/MSTest.Analyzers.CodeFixes/xlf/CodeFixResources.zh-Hant.xlf	Adds localized entry for the new code-fix title.

Copilot's findings

• Files reviewed: 16/16 changed files
• Comments generated: 2

[github-actions]

Summary

Workflow: Expert Code Reviewer 🧠
Date: 2026-04-28
Repository: microsoft/testfx

Key Findings

[Correctness] Ambiguous/no-op fix when System.ComponentModel namespace is imported

File: src/Analyzers/MSTest.Analyzers.CodeFixes/DoNotUseSystemDescriptionAttributeFixer.cs (line 100)

The fix replaces the System attribute name with the bare identifier "Description". This works only in the narrow case where using Microsoft.VisualStudio.TestTools.UnitTesting; is in scope and using System.ComponentModel; is not.

Two broken scenarios the current test suite does not cover:

• Both namespaces imported → [Description] becomes ambiguous (CS0104), producing non-compiling code.
• Only System.ComponentModel imported (with a fully-qualified [Microsoft.VisualStudio.TestTools.UnitTesting.TestMethod]) → the replacement is syntactically identical to what was there before; the MSTest namespace still isn't in scope for Description, so the diagnostic would still fire.

Recommended fix: Use the fully-qualified MSTest name annotated with Simplifier.Annotation, letting the workspace simplifier reduce it only when the reference is unambiguous:

// using Microsoft.CodeAnalysis.Simplification;

AttributeSyntax newAttribute = systemDescriptionAttribute.WithName(
    SyntaxFactory.ParseName("Microsoft.VisualStudio.TestTools.UnitTesting.Description")
        .WithTriviaFrom(systemDescriptionAttribute.Name)
        .WithAdditionalAnnotations(Simplifier.Annotation));

SyntaxNode root = await document.GetRequiredSyntaxRootAsync(cancellationToken).ConfigureAwait(false);
Document updatedDocument = document.WithSyntaxRoot(root.ReplaceNode(systemDescriptionAttribute, newAttribute));
return await Simplifier.ReduceAsync(updatedDocument, cancellationToken: cancellationToken).ConfigureAwait(false);

A new test case should be added to cover the scenario where using System.ComponentModel; is also present, verifying that the result is unambiguous.

Positive Observations

• The semantic-model–based attribute discovery (iterating attribute lists and comparing ContainingType via SymbolEqualityComparer) is correct and robust across fully-qualified and simple-name forms.
• GetFixAllProvider() → BatchFixer is the right choice for this single-replacement fix.
• ConfigureAwait(false) is consistently applied on all awaited calls.
• The .xlf localization files were auto-generated (not hand-edited), matching the repo convention.

---

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[Evangelink]

@copilot resolve the merge conflicts in this pull request and address review comments

[Copilot]

@copilot resolve the merge conflicts in this pull request and address review comments

Resolved the merge conflict in CodeFixResources.resx (now includes both RemoveDuplicateDataRowFix from main and UseMSTestDescriptionAttributeInsteadFix) and updated the fixer to use Simplifier.ReduceAsync with the fully-qualified Microsoft.VisualStudio.TestTools.UnitTesting.DescriptionAttribute name — this ensures correctness in all scenarios (ambiguous using System.ComponentModel, no using directives). Commit: 2b6086a.

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  • Triggering command: /usr/bin/dotnet dotnet build test/UnitTests/MSTest.Analyzers.UnitTests/MSTest.Analyzers.UnitTests.csproj -c Debug (dns block)
  • Triggering command: /usr/bin/dotnet dotnet test test/UnitTests/MSTest.Analyzers.UnitTests/MSTest.Analyzers.UnitTests.csproj -c Debug --filter DoNotUseSystemDescriptionAttributeAnalyzerTests (dns block)
• s4uvsblobprodcus326.vsblob.vsassets.io
  • Triggering command: /usr/bin/dotnet dotnet build test/UnitTests/MSTest.Analyzers.UnitTests/MSTest.Analyzers.UnitTests.csproj -c Debug (dns block)
  • Triggering command: /usr/bin/dotnet dotnet test test/UnitTests/MSTest.Analyzers.UnitTests/MSTest.Analyzers.UnitTests.csproj -c Debug --filter DoNotUseSystemDescriptionAttributeAnalyzerTests (dns block)
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  • Triggering command: /home/REDACTED/work/testfx/testfx/artifacts/bin/MSTest.Analyzers.UnitTests/Debug/net8.0/MSTest.Analyzers.UnitTests /home/REDACTED/work/testfx/testfx/artifacts/bin/MSTest.Analyzers.UnitTests/Debug/net8.0/MSTest.Analyzers.UnitTests --diagnostic --diagnostic-output-directory /home/REDACTED/work/testfx/testfx/artifacts/log/Debug --diagnostic-file-prefix MSTest.Analyzers.UnitTests_net8.0_Debug_x64 --diagnostic-verbosity trace --crashdump --hangdump --hangdump-timeout 15m --report-azdo --coverage --coverage-settings /home/REDACTED/work/testfx/testfx/test/coverage.config --coverage-output MSTest.Analyzers.UnitTests_net8.0_Debug_x64.coverage --filter DoNotUseSystemDescriptionAttributeAnalyzerTests (dns block)

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[Evangelink]

@copilot resolve the merge conflicts in this pull request

[Copilot]

@copilot resolve the merge conflicts in this pull request

Resolved the remaining merge conflicts in CodeFixResources.resx and formal-verification/TARGETS.md by merging the latest main. Commit: 0cc145c.

[Evangelink]

@copilot resolve the merge conflicts in this pull request

[Copilot]

@copilot resolve the merge conflicts in this pull request

Resolved. Created a proper merge commit (18b3fdb) with two parents — the previous merge attempt was a single-parent commit. The branch is now fully up to date with main.

[Evangelink]

Summary

Workflow: Test Expert Reviewer 🧪
Date: 2026-04-30
Repository: microsoft/testfx

Key Findings

Good: Tests are well-isolated, use strong VerifyCodeFixAsync assertions that verify both the diagnostic location (via [|...|] markers) and the exact post-fix code. No shared mutable state, no timing dependencies, no flakiness patterns.

Coverage gap (1 finding): The PR description explicitly describes a scenario where the user writes the short form [Description("...")] with using System.ComponentModel in scope (where it resolves to System.ComponentModel.DescriptionAttribute). None of the three new code-fix tests cover this form — they all use the fully-qualified [System.ComponentModel.Description("...")] input. The inline comment above details the missing test case.

Recommendations

1. Add a test for [Description("...")] (short form) + using System.ComponentModel in scope → fixer should produce [Microsoft.VisualStudio.TestTools.UnitTesting.Description("...")]. See inline comment for suggested test.

---

Generated by Test Expert Reviewer

🧪 Test quality reviewed by Test Expert Reviewer 🧪

[Evangelink]

[Coverage] The PR description explicitly calls out a key scenario that is not tested: the user writes the short form [Description("...")] when using System.ComponentModel is in scope, and that short form resolves to System.ComponentModel.DescriptionAttribute. The current test (WhenTestMethodHasSystemDescriptionAttributeWithSystemComponentModelUsing) only covers the fully-qualified input [System.ComponentModel.Description("...")].

Impact: If the fixer silently fails (returns the original document) or produces incorrect output for the short-form input, no test would catch it.

Suggestion: Add a complementary test case:

[TestMethod]
public async Task WhenTestMethodHasShortFormDescriptionAttributeWithSystemComponentModelUsing_UsesFullyQualifiedMSTestDescription()
{
    string code = """
        using System.ComponentModel;
        using Microsoft.VisualStudio.TestTools.UnitTesting;

        [TestClass]
        public class MyTestClass
        {
            [TestMethod]
            [Description("Description")]
            public void [|MyTestMethod|]()
            {
            }
        }
        """;

    string fixedCode = """
        using System.ComponentModel;
        using Microsoft.VisualStudio.TestTools.UnitTesting;

        [TestClass]
        public class MyTestClass
        {
            [TestMethod]
            [Microsoft.VisualStudio.TestTools.UnitTesting.Description("Description")]
            public void MyTestMethod()
            {
            }
        }
        """;

    await VerifyCS.VerifyCodeFixAsync(code, fixedCode);
}

This is the scenario described in the PR body under "Before / After (with using System.ComponentModel also imported)".

[Evangelink]

Summary

Workflow: Expert Code Reviewer 🧠
Date: 2026-04-30
Repository: microsoft/testfx

Key Findings

No issues found. The implementation is correct and well-structured across all review dimensions.

Correctness ✅

• RegisterCodeFixesAsync correctly locates the MethodDeclarationSyntax by walking up from the diagnostic's token (placed on the method identifier by methodSymbol.CreateDiagnostic).
• ReplaceWithMSTestDescriptionAttributeAsync uses the semantic model to identify the exact System.ComponentModel.DescriptionAttribute constructor symbol (via GetSymbolInfo + SymbolEqualityComparer.Default), which robustly handles aliases and qualified names.
• The Simplifier.Annotation + Simplifier.ReduceAsync pattern correctly produces the minimal unambiguous form: simplified to [Description] when MSTest namespace is in scope without conflict, kept fully-qualified when using System.ComponentModel is also present or when no using is present. All three cases are tested.
• The fully-qualified name Microsoft.VisualStudio.TestTools.UnitTesting.DescriptionAttribute is correctly simplified by Roslyn (including Attribute suffix elision in attribute position) to match expected test outputs.

Threading / Concurrency ✅
Design-time code-fixer code; no static mutable state; ConfigureAwait(false) used consistently throughout all async paths.

Performance ✅
Not on a hot path; Roslyn caches the syntax tree so the double root retrieval (RegisterCodeFixesAsync + ReplaceWithMSTestDescriptionAttributeAsync) has no real cost.

Public API & Binary Compatibility ✅
New public sealed class, pure addition. No existing API changes.

Cross-TFM ✅
Analyzer targets C#+VB; fixer is C#-only (standard practice). No TFM-specific APIs used without guards.

Resources / IDisposable ✅
No disposables introduced without cleanup.

Security ✅
Operates purely on Roslyn syntax/semantic APIs; no injection or path traversal risk.

Defensive Coding ✅
Null guards at all early-exit points; systemDescriptionAttributeSymbol is null and methodDeclaration is null checks both present.

Positive Observations

• Follows all established code-fixer patterns in the codebase (same structure as UseAttributeOnTestMethodFixer, PreferDisposeOverTestCleanupFixer, etc.).
• WellKnownTypeNames constants reused correctly — no magic strings in the fixer.
• Three well-chosen test scenarios cover: typical case, ambiguity case (both usings), and no-using case.

---

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