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Fix crash in convert-if-to-switch #81724

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Merged
CyrusNajmabadi merged 2 commits into from
Dec 16, 2025
Merged

Fix crash in convert-if-to-switch #81724

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54ae3a6
Fix crash in convert-if-to-switch
CyrusNajmabadi Dec 16, 2025
cf75860
Revert
CyrusNajmabadi Dec 16, 2025
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11 changes: 11 additions & 0 deletions src/Features/CSharpTest/ConvertIfToSwitch/ConvertIfToSwitchTests.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -2794,4 +2794,15 @@ int M(R v)
""",
LanguageVersion = LanguageVersion.CSharp14,
}.RunAsync();

[Fact, WorkItem("https://github.com/dotnet/roslyn/issues/81714")]
public Task TestNullableBool()
=> new VerifyCS.Test
{
TestCode = """
[||]if ((bool?)null == false) { }
""",
LanguageVersion = LanguageVersion.CSharp14,
TestState = { OutputKind = OutputKind.ConsoleApplication }
}.RunAsync();
}
28 changes: 15 additions & 13 deletions ...e/Portable/ConvertIfToSwitch/AbstractConvertIfToSwitchCodeRefactoringProvider.Analyzer.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -4,6 +4,7 @@

using System;
using System.Collections.Immutable;
using System.Diagnostics.CodeAnalysis;
using Microsoft.CodeAnalysis.LanguageService;
using Microsoft.CodeAnalysis.Operations;
using Microsoft.CodeAnalysis.PooledObjects;
Expand Down Expand Up @@ -255,8 +256,8 @@ private ConstantResult DetermineConstant(IBinaryOperation op)
{
return (op.LeftOperand, op.RightOperand) switch
{
var (e, v) when IsConstant(v) && CheckTargetExpression(e) && CheckConstantType(v) => ConstantResult.Right,
var (v, e) when IsConstant(v) && CheckTargetExpression(e) && CheckConstantType(v) => ConstantResult.Left,
var (e, v) when IsConstant(v) && CheckTargetExpression(e, out var switchTargetType) && CheckConstantType(v, switchTargetType) => ConstantResult.Right,
var (v, e) when IsConstant(v) && CheckTargetExpression(e, out var switchTargetType) && CheckConstantType(v, switchTargetType) => ConstantResult.Left,
_ => ConstantResult.None,
};
}
Expand Down Expand Up @@ -330,11 +331,11 @@ when Supports(Feature.AndPattern | Feature.CaseGuard):
}

case IIsTypeOperation op
when Supports(Feature.IsTypePattern) && CheckTargetExpression(op.ValueOperand) && op.Syntax is TIsExpressionSyntax node:
when Supports(Feature.IsTypePattern) && CheckTargetExpression(op.ValueOperand, out _) && op.Syntax is TIsExpressionSyntax node:
return new AnalyzedPattern.Type(node);

case IIsPatternOperation op
when Supports(Feature.SourcePattern) && CheckTargetExpression(op.Value) && op.Pattern.Syntax is TPatternSyntax pattern:
when Supports(Feature.SourcePattern) && CheckTargetExpression(op.Value, out _) && op.Pattern.Syntax is TPatternSyntax pattern:
return new AnalyzedPattern.Source(pattern);

case IParenthesizedOperation op:
Expand Down Expand Up @@ -390,7 +391,7 @@ when CheckTargetExpression(low.Expression, high.Expression) => (low.Value.Syntax
};

bool CheckTargetExpression(IOperation left, IOperation right)
=> _syntaxFacts.AreEquivalent(left.Syntax, right.Syntax) && this.CheckTargetExpression(left);
=> _syntaxFacts.AreEquivalent(left.Syntax, right.Syntax) && this.CheckTargetExpression(left, out _);
}

private static (BoundKind Kind, IOperation Expression, IOperation Value) GetRangeBound(IBinaryOperation op)
Expand Down Expand Up @@ -447,33 +448,34 @@ private static bool IsConstant(IOperation operation)
: operation.ConstantValue.HasValue;
}

private bool CheckTargetExpression(IOperation operation)
private bool CheckTargetExpression(IOperation operation, [NotNullWhen(true)] out ITypeSymbol? switchTargetType)
{
operation = operation.WalkDownConversion();

if (operation.Syntax is not TExpressionSyntax expression)
{
switchTargetType = null;
return false;
}

// If we have not figured the switch expression yet,
// we will assume that the first expression is the one.
// If we have not figured the switch expression yet, we will assume that the first expression is the one.
if (_switchTargetExpression is null)
{
RoslynDebug.Assert(_switchTargetType is null);

_switchTargetExpression = expression;
_switchTargetType = operation.Type;
return true;
}

return _syntaxFacts.AreEquivalent(expression, _switchTargetExpression);
switchTargetType = _switchTargetType;
return switchTargetType != null && _syntaxFacts.AreEquivalent(expression, _switchTargetExpression);
}

private bool CheckConstantType(IOperation operation)
private bool CheckConstantType(IOperation operation, ITypeSymbol switchTargetType)
{
RoslynDebug.AssertNotNull(operation.SemanticModel);
RoslynDebug.AssertNotNull(_switchTargetType);

return CanImplicitlyConvert(operation.SemanticModel, operation.Syntax, _switchTargetType);
return CanImplicitlyConvert(operation.SemanticModel, operation.Syntax, switchTargetType);
}
}

Expand Down
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