public void IsObjectEquals(string check, bool expected)
{
var testCode = @"
namespace RoslynSandbox
{
using System;
public class Foo
{
private int? bar1;
private Nullable<int> bar2;
private int bar3;
private double? bar4;
private string bar5;
public Foo()
{
Equals(this.bar1, this.bar1);
}
public int? Bar1 => this.bar1;
}
}";
testCode = testCode.AssertReplace("Equals(this.bar1, this.bar1)", check);
var syntaxTree = CSharpSyntaxTree.ParseText(testCode);
var compilation = CSharpCompilation.Create("test", new[] { syntaxTree }, MetadataReferences.FromAttributes());
var semanticModel = compilation.GetSemanticModel(syntaxTree);
var invocation = syntaxTree.FindInvocation(check);
var arg0 = semanticModel.GetSymbolSafe(invocation.ArgumentList.Arguments[0].Expression, CancellationToken.None);
var arg1 = semanticModel.GetSymbolSafe(invocation.ArgumentList.Arguments[1].Expression, CancellationToken.None);
Assert.AreEqual(expected, Equality.IsObjectEquals(invocation, semanticModel, CancellationToken.None, arg0, arg1));
Assert.AreEqual(expected, Equality.IsObjectEquals(invocation, semanticModel, CancellationToken.None, arg1, arg0));
}
private static void HandleInvocation(SyntaxNodeAnalysisContext context)
{
if (context.IsExcludedFromAnalysis())
{
return;
}
var ifStatement = (IfStatementSyntax)context.Node;
if (ifStatement?.Condition == null)
{
return;
}
var setter = ifStatement.FirstAncestorOrSelf <AccessorDeclarationSyntax>();
if (setter?.IsKind(SyntaxKind.SetAccessorDeclaration) != true)
{
return;
}
if (!Notifies(setter, context.SemanticModel, context.CancellationToken))
{
return;
}
var propertyDeclaration = setter.FirstAncestorOrSelf <PropertyDeclarationSyntax>();
var property = context.SemanticModel.GetDeclaredSymbolSafe(propertyDeclaration, context.CancellationToken);
if (property == null ||
property.Type.IsValueType ||
property.Type == KnownSymbol.String)
{
return;
}
if (!Property.TryGetBackingField(property, context.SemanticModel, context.CancellationToken, out IFieldSymbol backingField))
{
return;
}
if (Property.TryFindValue(setter, context.SemanticModel, context.CancellationToken, out IParameterSymbol value))
{
foreach (var member in new ISymbol[] { backingField, property })
{
if (Equality.IsObjectEquals(ifStatement.Condition, context.SemanticModel, context.CancellationToken, value, member) ||
IsNegatedObjectEqualsCheck(ifStatement.Condition, context.SemanticModel, context.CancellationToken, value, member))
{
if (Equality.UsesObjectOrNone(ifStatement.Condition))
{
return;
}
}
}
}
context.ReportDiagnostic(Diagnostic.Create(Descriptor, ifStatement.GetLocation()));
}
private static bool IsNegatedObjectEqualsCheck(ExpressionSyntax expression, SemanticModel semanticModel, CancellationToken cancellationToken, IParameterSymbol value, ISymbol member)
{
var unaryExpression = expression as PrefixUnaryExpressionSyntax;
if (unaryExpression?.IsKind(SyntaxKind.LogicalNotExpression) == true)
{
return(Equality.IsObjectEquals(unaryExpression.Operand, semanticModel, cancellationToken, value, member));
}
return(false);
}
private static bool CanFix(IfStatementSyntax ifStatement, SemanticModel semanticModel, CancellationToken cancellationToken, IParameterSymbol value, IFieldSymbol backingField, IPropertySymbol property)
{
foreach (var member in new ISymbol[] { backingField, property })
{
if (Equality.IsOperatorEquals(ifStatement.Condition, semanticModel, cancellationToken, value, member) ||
Equality.IsObjectEquals(ifStatement.Condition, semanticModel, cancellationToken, value, member) ||
Equality.IsReferenceEquals(ifStatement.Condition, semanticModel, cancellationToken, value, member) ||
Equality.IsInstanceEquals(ifStatement.Condition, semanticModel, cancellationToken, value, member) ||
Equality.IsInstanceEquals(ifStatement.Condition, semanticModel, cancellationToken, member, value))
{
return(true);
}
}
return(false);
}
private static bool IsEqualsCheck(ExpressionSyntax expression, SemanticModel semanticModel, CancellationToken cancellationToken, IParameterSymbol value, ISymbol member)
{
var equals = expression as InvocationExpressionSyntax;
if (equals == null)
{
return(false);
}
if (Equality.IsObjectEquals(equals, semanticModel, cancellationToken, value, member) ||
Equality.IsInstanceEquals(equals, semanticModel, cancellationToken, value, member) ||
Equality.IsInstanceEquals(equals, semanticModel, cancellationToken, member, value) ||
Equality.IsReferenceEquals(equals, semanticModel, cancellationToken, value, member) ||
Equality.IsEqualityComparerEquals(equals, semanticModel, cancellationToken, value, member) ||
Equality.IsNullableEquals(equals, semanticModel, cancellationToken, value, member))
{
return(true);
}
return(false);
}
