private static void Handle(SyntaxNodeAnalysisContext context)
{
if (context.IsExcludedFromAnalysis())
{
return;
}
if (context.Node is AssignmentExpressionSyntax assignment &&
!context.ContainingSymbol.IsStatic &&
IsInConstructor(assignment) &&
Property.TryGetAssignedProperty(assignment, out var propertyDeclaration) &&
propertyDeclaration.TryGetSetter(out var setter) &&
(setter.Body != null || setter.ExpressionBody != null) &&
!ThrowWalker.Throws(setter))
{
using (var mutations = MutationWalker.Borrow(setter))
{
if (mutations.Count > 1)
{
return;
}
if (mutations.TrySingle(out var mutation) &&
mutation is AssignmentExpressionSyntax setAssignment &&
setAssignment.Right is IdentifierNameSyntax identifierName &&
identifierName.Identifier.ValueText != "value")
{
return;
}
}
using (var walker = InvocationWalker.Borrow(setter))
{
foreach (var invocation in walker.Invocations)
{
if (invocation.TryGetInvokedMethodName(out var name) &&
(name == "Equals" || name == "nameof"))
{
continue;
}
if (PropertyChanged.IsSetAndRaiseCall(invocation, context.SemanticModel, context.CancellationToken) != AnalysisResult.No)
{
continue;
}
if (PropertyChanged.IsOnPropertyChanged(invocation, context.SemanticModel, context.CancellationToken) != AnalysisResult.No ||
PropertyChanged.IsPropertyChangedInvoke(invocation, context.SemanticModel, context.CancellationToken))
{
continue;
}
return;
}
}
context.ReportDiagnostic(Diagnostic.Create(Descriptor, assignment.GetLocation()));
}
}
internal static bool TryFindSingleMutation(AccessorDeclarationSyntax setter, SemanticModel semanticModel, CancellationToken cancellationToken, [NotNullWhen(true)] out ExpressionSyntax?backing)
{
backing = null;
using (var mutations = MutationWalker.Borrow(setter, SearchScope.Member, semanticModel, cancellationToken))
{
if (mutations.All().TrySingle(x => x.IsEither(SyntaxKind.SimpleAssignmentExpression, SyntaxKind.Argument), out var mutation))
{
return(mutation switch
{
AssignmentExpressionSyntax assignment => IsMutation(assignment, semanticModel, cancellationToken, out _, out backing),
ArgumentSyntax {
Parent : ArgumentListSyntax {
Parent : InvocationExpressionSyntax invocation
}
} => IsMutation(invocation, semanticModel, cancellationToken, out _, out backing),
private static void Handle(SyntaxNodeAnalysisContext context)
{
if (!context.IsExcludedFromAnalysis() &&
context.Node is PropertyDeclarationSyntax propertyDeclaration &&
context.ContainingSymbol is IPropertySymbol property)
{
using (var walker = ReturnExpressions(propertyDeclaration))
{
foreach (var returnValue in walker.ReturnValues)
{
if (IsProperty(returnValue))
{
context.ReportDiagnostic(Diagnostic.Create(Descriptors.INPC015PropertyIsRecursive, returnValue.GetLocation(), "Getter returns property, infinite recursion"));
}
}
if (walker.ReturnValues.TrySingle(out var single))
{
if (single.IsEither(SyntaxKind.SimpleMemberAccessExpression, SyntaxKind.IdentifierName) &&
MemberPath.TrySingle(single, out var path) &&
context.SemanticModel.TryGetSymbol(path, context.CancellationToken, out IFieldSymbol? backingField))
{
if (!HasMatchingName(backingField, property))
{
context.ReportDiagnostic(Diagnostic.Create(Descriptors.INPC017BackingFieldNameMisMatch, path.GetLocation()));
}
if (propertyDeclaration.TryGetSetter(out var setAccessor))
{
using var mutationWalker = MutationWalker.Borrow(setAccessor, SearchScope.Member, context.SemanticModel, context.CancellationToken);
if (mutationWalker.IsEmpty)
{
context.ReportDiagnostic(Diagnostic.Create(Descriptors.INPC021SetBackingField, setAccessor.GetLocation()));
}
}
}
if (single is LiteralExpressionSyntax &&
propertyDeclaration.TryGetSetter(out var set) &&
Setter.TryFindSingleMutation(set, context.SemanticModel, context.CancellationToken, out var fieldAccess))
{
context.ReportDiagnostic(
Diagnostic.Create(
Descriptors.INPC019GetBackingField,
single.GetLocation(),
additionalLocations: new[] { fieldAccess.GetLocation() }));
}
}
}
if (propertyDeclaration.TryGetSetter(out var setter))
{
if (ShouldBeExpressionBody(setter))
{
context.ReportDiagnostic(Diagnostic.Create(Descriptors.INPC020PreferExpressionBodyAccessor, setter.GetLocation()));
}
if (Property.GetsAndSetsSame(propertyDeclaration, context.SemanticModel, context.CancellationToken, out _, out _) == false)
{
context.ReportDiagnostic(Diagnostic.Create(Descriptors.INPC010GetAndSetSame, propertyDeclaration.Identifier.GetLocation()));
}
using (var assignmentWalker = AssignmentWalker.Borrow(setter))
{
if (assignmentWalker.Assignments.TryFirst(x => IsProperty(x.Left) && !x.Parent.IsKind(SyntaxKind.ObjectInitializerExpression), out var recursiveAssignment))
{
context.ReportDiagnostic(Diagnostic.Create(Descriptors.INPC015PropertyIsRecursive, recursiveAssignment.Left.GetLocation(), "Setter assigns property, infinite recursion"));
}
}
if (propertyDeclaration.TryGetGetter(out var getter))
{
if (ShouldBeExpressionBody(getter))
{
context.ReportDiagnostic(Diagnostic.Create(Descriptors.INPC020PreferExpressionBodyAccessor, getter.GetLocation()));
}
}
}
bool IsProperty(ExpressionSyntax expression)
{
if (property.ExplicitInterfaceImplementations.Any())
{
return(false);
}
return(expression switch
{
IdentifierNameSyntax {
Identifier: { ValueText : { } name }
} => property.Name == name,
MemberAccessExpressionSyntax {
Expression : ThisExpressionSyntax _, Name : { Identifier : { ValueText : { } name } }
} => property.Name == name,
