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Fix: Preserve verbatim identifiers in tuple element names during code generation#80980

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CyrusNajmabadi merged 3 commits intomainfrom
copilot/fix-generate-method-issue
Nov 3, 2025
Merged

Fix: Preserve verbatim identifiers in tuple element names during code generation#80980
CyrusNajmabadi merged 3 commits intomainfrom
copilot/fix-generate-method-issue

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Copilot AI commented Nov 2, 2025 •
edited by CyrusNajmabadi
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  • Explore repository structure and understand the issue
  • Locate the code generation for tuple types with element names
  • Identify the root cause: ITypeSymbolExtensions.TypeSyntaxGeneratorVisitor.CreateTupleTypeSyntax uses Identifier(element.Name) instead of properly escaping identifiers
  • Add test case reproducing the issue
  • Fix the bug by using ToIdentifierToken() extension method for tuple element names
  • Build and verify the fix compiles
  • Format code
  • Run code review - no issues found
  • Run security check - no issues found
  • Address PR feedback - Add WorkItem attribute to test

Summary

Fixed the issue where Generate Method (and other code generation features) would drop verbatim identifiers from tuple element names.

Changes Made:

  1. Modified ITypeSymbolExtensions.TypeSyntaxGeneratorVisitor.CreateTupleTypeSyntax to use element.Name.ToIdentifierToken() instead of Identifier(element.Name) to properly escape keyword identifiers
  2. Added test TestGenerateMethodWithTupleVerbatimIdentifiers to verify verbatim identifiers are preserved with WorkItem attribute

Example:

  • Before: (char char, int int) M2() ❌ (invalid C#)
  • After: (char @char, int @int) M2() ✅ (valid C#)

The fix follows the same pattern used elsewhere in the codebase (e.g., CSharpSyntaxGenerator.TupleElementExpression).

Original prompt

This section details on the original issue you should resolve

<issue_title>"Generate method" drops verbatim identifiers from value tuple names</issue_title>
<issue_description>Version Used: VS 18.0.0 Insiders [11123.170]

Steps to Reproduce:
Open the lightbulb menu on the M2 token and select "Generate method 'M2'".

class C
{
    void M1()
    {
        (char @char, int @int) x = M2();
    }
}

Expected Behavior:
The following method is generated (verbatim identifiers are retained to get legal code):

private (char @char, int @int) M2()
{
    throw new NotImplementedException();
}

Actual Behavior:
The following method is generated, which results in lots of compiler errors.

private (char char, int int) M2()
{
    throw new NotImplementedException();
}

The same happens for all other "Generate" commands (property, field, etc).</issue_description>

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@CyrusNajmabadi
Fix: Use ToIdentifierToken for tuple element names to preserve verbat…
04de2e6 
…im identifiers

Co-authored-by: CyrusNajmabadi <4564579+CyrusNajmabadi@users.noreply.github.com>
Copilot AI changed the title [WIP] Fix generate method to retain verbatim identifiers in tuples Fix: Preserve verbatim identifiers in tuple element names during code generation Nov 2, 2025
Copilot AI requested a review from CyrusNajmabadi November 2, 2025 02:04
@CyrusNajmabadi CyrusNajmabadi marked this pull request as ready for review November 2, 2025 02:04
@CyrusNajmabadi CyrusNajmabadi requested a review from a team as a code owner November 2, 2025 02:04
CyrusNajmabadi
CyrusNajmabadi reviewed Nov 2, 2025
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src/Analyzers/CSharp/Tests/GenerateMethod/GenerateMethodTests.cs Outdated
""",
index: 1);

[Fact]
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@CyrusNajmabadi CyrusNajmabadi Nov 2, 2025

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@copilot please add the right WorkItem attribute here like so: [Fact, WorkItem("url")]

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Copilot AI Nov 2, 2025

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Added WorkItem attribute in e4473f2.

@CyrusNajmabadi
Add WorkItem attribute to TestGenerateMethodWithTupleVerbatimIdentifiers
e4473f2 
Co-authored-by: CyrusNajmabadi <4564579+CyrusNajmabadi@users.noreply.github.com>
Copilot AI requested a review from CyrusNajmabadi November 2, 2025 02:09
@CyrusNajmabadi
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CyrusNajmabadi commented Nov 3, 2025

@dotnet/roslyn-ide ptal.

@CyrusNajmabadi CyrusNajmabadi merged commit 01c1e59 into main Nov 3, 2025
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@CyrusNajmabadi CyrusNajmabadi deleted the copilot/fix-generate-method-issue branch November 3, 2025 18:00
@dotnet-policy-service dotnet-policy-service bot added this to the Next milestone Nov 3, 2025
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@davidwengier davidwengier modified the milestones: Next, 18.3 Jan 6, 2026
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@JoeRobich JoeRobich JoeRobich approved these changes

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@CyrusNajmabadi CyrusNajmabadi CyrusNajmabadi approved these changes

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"Generate method" drops verbatim identifiers from value tuple names

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