S1186: also inspect empty set and init and empty local functions

analyzers/src/SonarAnalyzer.CSharp/Extensions/SyntaxNodeExtensions.cs

@@ -19,6 +19,7 @@
  */
 
 using SonarAnalyzer.CFG.Roslyn;
+using StyleCop.Analyzers.Lightup;
 
 namespace SonarAnalyzer.Extensions
 {
@@ -488,6 +489,15 @@ private static string GetUnknownType(SyntaxKind kind) =>
 
 #endif
 
+        public static BlockSyntax GetBody(this SyntaxNode node) =>
+            node switch
+            {
+                BaseMethodDeclarationSyntax method => method.Body,
+                AccessorDeclarationSyntax accessor => accessor.Body,
+                _ when LocalFunctionStatementSyntaxWrapper.IsInstance(node) => ((LocalFunctionStatementSyntaxWrapper)node).Body,
+                _ => null,
+            };
+
         public static SyntaxNode GetInitializer(this SyntaxNode node) =>
             node switch
             {
@@ -496,6 +506,14 @@ public static SyntaxNode GetInitializer(this SyntaxNode node) =>
                 _ => null
             };
 
+        public static SyntaxTokenList GetModifiers(this SyntaxNode? node) =>
+            node switch
+            {
+                AccessorDeclarationSyntax accessor => accessor.Modifiers,
+                MemberDeclarationSyntax member => member.Modifiers(),
+                _ => default,
+            };
+
         public static bool IsTrue(this SyntaxNode node) =>
             node switch
             {

analyzers/src/SonarAnalyzer.CSharp/Rules/AbstractTypesShouldNotHaveConstructors.cs

@@ -34,9 +34,9 @@ protected override void Initialize(SonarAnalysisContext context) =>
             context.RegisterNodeAction(
                 c =>
                 {
-                    if (GetModifiers(c.Node.Parent).Any(SyntaxKind.AbstractKeyword))
+                    if (c.Node.Parent.GetModifiers().Any(SyntaxKind.AbstractKeyword))
                     {
-                        var invalidAccessModifier = GetModifiers(c.Node).FirstOrDefault(IsPublicOrInternal);
+                        var invalidAccessModifier = c.Node.GetModifiers().FirstOrDefault(IsPublicOrInternal);
                         if (invalidAccessModifier != default)
                         {
                             c.ReportIssue(Diagnostic.Create(Rule, invalidAccessModifier.GetLocation(), SuggestModifier(invalidAccessModifier)));
@@ -45,15 +45,6 @@ protected override void Initialize(SonarAnalysisContext context) =>
                 },
                 SyntaxKind.ConstructorDeclaration);
 
-        private static SyntaxTokenList GetModifiers(SyntaxNode node) =>
-            node switch
-            {
-                ClassDeclarationSyntax classDeclaration => classDeclaration.Modifiers,
-                ConstructorDeclarationSyntax ctorDeclaration => ctorDeclaration.Modifiers,
-                {} syntaxNode when RecordDeclarationSyntaxWrapper.IsInstance(syntaxNode) => ((RecordDeclarationSyntaxWrapper)syntaxNode).Modifiers,
-                _ => default
-            };
-
         private static bool IsPublicOrInternal(SyntaxToken token) =>
             token.IsKind(SyntaxKind.PublicKeyword) || token.IsKind(SyntaxKind.InternalKeyword);
 

analyzers/src/SonarAnalyzer.CSharp/Rules/EmptyMethod.cs

@@ -23,42 +23,43 @@ namespace SonarAnalyzer.Rules.CSharp
     [DiagnosticAnalyzer(LanguageNames.CSharp)]
     public sealed class EmptyMethod : EmptyMethodBase<SyntaxKind>
     {
+        internal static readonly SyntaxKind[] SupportedSyntaxKinds =
+        {
+            SyntaxKind.MethodDeclaration,
+            SyntaxKindEx.LocalFunctionStatement,
+            SyntaxKind.SetAccessorDeclaration,
+            SyntaxKindEx.InitAccessorDeclaration
+        };
+
         protected override ILanguageFacade<SyntaxKind> Language => CSharpFacade.Instance;
 
-        protected override SyntaxKind[] SyntaxKinds { get; } =
-            {
-                SyntaxKind.MethodDeclaration,
-                SyntaxKindEx.LocalFunctionStatement
-            };
+        protected override SyntaxKind[] SyntaxKinds => SupportedSyntaxKinds;
 
         protected override void CheckMethod(SonarSyntaxNodeReportingContext context)
         {
-            if (LocalFunctionStatementSyntaxWrapper.IsInstance(context.Node))
-            {
-                var wrapper = (LocalFunctionStatementSyntaxWrapper)context.Node;
-                if (wrapper.Body is { } body && body.IsEmpty())
-                {
-                    context.ReportIssue(Diagnostic.Create(Rule, wrapper.Identifier.GetLocation()));
-                }
-            }
-            else
+            // No need to check for ExpressionBody as arrowed methods can't be empty
+            if (context.Node.GetBody() is { } body
+                && body.IsEmpty()
+                && !ShouldBeExcluded(context, context.Node, context.Node.GetModifiers()))
             {
-                var methodDeclaration = (MethodDeclarationSyntax)context.Node;
-
-                // No need to check for ExpressionBody as arrowed methods can't be empty
-                if (methodDeclaration.Body is { } body
-                    && body.IsEmpty()
-                    && !ShouldMethodBeExcluded(context, methodDeclaration))
-                {
-                    context.ReportIssue(Diagnostic.Create(Rule, methodDeclaration.Identifier.GetLocation()));
-                }
+                context.ReportIssue(Diagnostic.Create(Rule, ReportingToken(context.Node).GetLocation()));
             }
         }
 
-        private static bool ShouldMethodBeExcluded(SonarSyntaxNodeReportingContext context, BaseMethodDeclarationSyntax methodNode) =>
-            methodNode.Modifiers.Any(SyntaxKind.VirtualKeyword)
-            || (context.SemanticModel.GetDeclaredSymbol(methodNode) is var symbol
-                && (symbol is { IsOverride: true, OverriddenMethod.IsAbstract: true } || !symbol.ExplicitOrImplicitInterfaceImplementations().IsEmpty))
-            || (methodNode.Modifiers.Any(SyntaxKind.OverrideKeyword) && context.IsTestProject());
+        private static bool ShouldBeExcluded(SonarSyntaxNodeReportingContext context, SyntaxNode node, SyntaxTokenList modifiers) =>
+            modifiers.Any(SyntaxKind.VirtualKeyword) // This quick check only works for methods, for accessors we need to check the symbol
+            || (context.SemanticModel.GetDeclaredSymbol(node) is IMethodSymbol symbol
+                && (symbol is { IsVirtual: true }
+                    || symbol is { IsOverride: true, OverriddenMethod.IsAbstract: true }
+                    || !symbol.ExplicitOrImplicitInterfaceImplementations().IsEmpty))
+            || (modifiers.Any(SyntaxKind.OverrideKeyword) && context.IsTestProject());
+
+        private static SyntaxToken ReportingToken(SyntaxNode node) =>
+            node switch
+            {
+                MethodDeclarationSyntax method => method.Identifier,
+                AccessorDeclarationSyntax accessor => accessor.Keyword,
+                _ => ((LocalFunctionStatementSyntaxWrapper)node).Identifier
+            };
     }
 }

analyzers/src/SonarAnalyzer.CSharp/Rules/EmptyMethodCodeFix.cs

@@ -36,20 +36,12 @@ public sealed class EmptyMethodCodeFix : SonarCodeFix
 
         protected override async Task RegisterCodeFixesAsync(SyntaxNode root, SonarCodeFixContext context)
         {
-            var diagnostic = context.Diagnostics.First();
-            var diagnosticSpan = diagnostic.Location.SourceSpan;
-            var syntaxNode = root.FindNode(diagnosticSpan, getInnermostNodeForTie: true);
-            var method = syntaxNode.FirstAncestorOrSelf<SyntaxNode>(x => x.IsAnyKind(SyntaxKind.MethodDeclaration, SyntaxKindEx.LocalFunctionStatement));
-            var methodBody = method.IsKind(SyntaxKind.MethodDeclaration)
-                ? ((BaseMethodDeclarationSyntax)method).Body
-                : ((LocalFunctionStatementSyntaxWrapper)method).Body;
-
-            if (methodBody.CloseBraceToken.IsMissing || methodBody.OpenBraceToken.IsMissing)
+            if (root.FindNode(context.Diagnostics.First().Location.SourceSpan, getInnermostNodeForTie: true)
+                .FirstAncestorOrSelf<SyntaxNode>(x => x.IsAnyKind(EmptyMethod.SupportedSyntaxKinds))
+                .GetBody() is { CloseBraceToken.IsMissing: false, OpenBraceToken.IsMissing: false } body)
             {
-                return;
+                await RegisterCodeFixesForMethodsAsync(context, root, body).ConfigureAwait(false);
             }
-
-            await RegisterCodeFixesForMethodsAsync(context, root, methodBody).ConfigureAwait(false);
         }
 
         private static async Task RegisterCodeFixesForMethodsAsync(SonarCodeFixContext context, SyntaxNode root, BlockSyntax methodBody)
@@ -70,9 +62,13 @@ private static async Task RegisterCodeFixesForMethodsAsync(SonarCodeFixContext c
                                 .Add(SyntaxFactory.Comment("// Method intentionally left empty."))
                                 .Add(SyntaxFactory.EndOfLine(Environment.NewLine))));
 
-                    var newRoot = root.ReplaceNode(
-                        methodBody,
-                        newMethodBody.WithTriviaFrom(methodBody).WithAdditionalAnnotations(Formatter.Annotation));
+                    var newRoot = methodBody.Parent is AccessorDeclarationSyntax accessor
+                        ? root.ReplaceNode(
+                            accessor,
+                            accessor.WithBody(newMethodBody.WithTriviaFrom(accessor.Body)).WithAdditionalAnnotations(Formatter.Annotation))
+                        : root.ReplaceNode(
+                            methodBody,
+                            newMethodBody.WithTriviaFrom(methodBody).WithAdditionalAnnotations(Formatter.Annotation));
                     return Task.FromResult(context.Document.WithSyntaxRoot(newRoot));
                 },
                 context.Diagnostics);
@@ -110,10 +106,7 @@ private static async Task RegisterCodeFixesForMethodsAsync(SonarCodeFixContext c
         }
 
         private static bool NamespaceNeedsToBeAdded(BlockSyntax methodBody, SemanticModel semanticModel) =>
-            !semanticModel.LookupNamespacesAndTypes(methodBody.CloseBraceToken.SpanStart)
-                .OfType<INamedTypeSymbol>()
-                .Any(x => x.IsType
-                          && x.Name == LiteralNotSupportedException
-                          && x.ContainingNamespace.Name == LiteralSystem);
+            semanticModel.LookupNamespacesAndTypes(methodBody.CloseBraceToken.SpanStart)
+                .All(x => x is not INamedTypeSymbol { IsType: true, Name: LiteralNotSupportedException, ContainingNamespace.Name: LiteralSystem });
     }
 }

analyzers/src/SonarAnalyzer.CSharp/Rules/ReturnEmptyCollectionInsteadOfNull.cs

@@ -68,6 +68,13 @@ void ReportIfAny(List<Location> nullOrDefaultLiterals)
         }
     }
 
+    private static BlockSyntax GetBody(SyntaxNode node) =>
+        node switch
+        {
+            PropertyDeclarationSyntax property => GetAccessor(property)?.Body,
+            _ => node.GetBody(),
+        };
+
     private static bool IsReturningCollection(SonarSyntaxNodeReportingContext context) =>
         GetType(context) is { } type
         && !type.Is(KnownType.System_String)
@@ -92,17 +99,8 @@ var _ when LocalFunctionStatementSyntaxWrapper.IsInstance(node) => ((LocalFuncti
                 _ => null,
             };
 
-    private static BlockSyntax GetBody(SyntaxNode node) =>
-        node switch
-        {
-            BaseMethodDeclarationSyntax method => method.Body,
-            PropertyDeclarationSyntax property => GetAccessor(property)?.Body,
-            var _ when LocalFunctionStatementSyntaxWrapper.IsInstance(node) => ((LocalFunctionStatementSyntaxWrapper)node).Body,
-            _ => null,
-        };
-
     private static AccessorDeclarationSyntax GetAccessor(PropertyDeclarationSyntax property) =>
-        property.AccessorList?.Accessors.FirstOrDefault(a => a.IsKind(SyntaxKind.GetAccessorDeclaration));
+        property.AccessorList?.Accessors.FirstOrDefault(x => x.IsKind(SyntaxKind.GetAccessorDeclaration));
 
     private static IEnumerable<SyntaxNode> GetReturnNullOrDefaultExpressions(SyntaxNode methodBlock) =>
         methodBlock.DescendantNodes(n =>

analyzers/tests/SonarAnalyzer.Test/Rules/EmptyMethodTest.cs

@@ -42,6 +42,7 @@ public void EmptyMethod() =>
         public void EmptyMethod_CSharp9() =>
             builderCS.AddPaths("EmptyMethod.CSharp9.cs")
                 .WithTopLevelStatements()
+                .WithOptions(ParseOptionsHelper.FromCSharp9)
                 .Verify();
 
         [TestMethod]

analyzers/tests/SonarAnalyzer.Test/TestCases/EmptyMethod.CSharp9.Comment.Fixed.cs

@@ -77,14 +77,6 @@ public override void F2()
     }
 }
 
-class WithProp
-{
-    public string Prop
-    {
-        init { } // FN https://github.com/SonarSource/sonar-dotnet/issues/3753
-    }
-}
-
 class M
 {
     [ModuleInitializer]
@@ -133,3 +125,58 @@ public partial void Qix()
         }
     }
 }
+
+class PropertyAccessors
+{
+    int EmptyInitProp { init
+        {
+            // Method intentionally left empty.
+        }
+    }                   // Fixed
+    int EmptyInitPropWithGet { get => 42;
+        init
+        {
+            // Method intentionally left empty.
+        }
+    } // Fixed
+    int AutoInitPropWithGet { get; init; }           // Compliant, auto-implemented, so not-empty
+
+    int EmptySetProp {
+        set
+        {
+            // Method intentionally left empty.
+        }
+    }                     // Fixed
+    int EmptySetPropWithGet { get => 42;
+        set
+        {
+            // Method intentionally left empty.
+        }
+    }   // Fixed
+    int AutoSetPropWithGet { get; set; }             // Compliant, auto-implemented, so not-empty
+
+    class Base
+    {
+        protected virtual int VirtualEmptyInitProp { init { } }  // Compliant, virtual
+    }
+
+    class Inherited : Base
+    {
+        protected override int VirtualEmptyInitProp {
+            init
+            {
+                // Method intentionally left empty.
+            }
+        } // Fixed
+    }
+
+    class Hidden : Base
+    {
+        protected new int VirtualEmptyInitProp {
+            init
+            {
+                // Method intentionally left empty.
+            }
+        }      // Fixed
+    }
+}

analyzers/tests/SonarAnalyzer.Test/TestCases/EmptyMethod.CSharp9.Throw.Fixed.cs

@@ -74,14 +74,6 @@ public override void F2()
     }
 }
 
-class WithProp
-{
-    public string Prop
-    {
-        init { } // FN https://github.com/SonarSource/sonar-dotnet/issues/3753
-    }
-}
-
 class M
 {
     [ModuleInitializer]
@@ -130,3 +122,29 @@ public partial void Qix()
         }
     }
 }
+
+class PropertyAccessors
+{
+    int EmptyInitProp { init { throw new NotSupportedException(); } }                   // Fixed
+    int EmptyInitPropWithGet { get => 42; init { throw new NotSupportedException(); } } // Fixed
+    int AutoInitPropWithGet { get; init; }           // Compliant, auto-implemented, so not-empty
+
+    int EmptySetProp { set { throw new NotSupportedException(); } }                     // Fixed
+    int EmptySetPropWithGet { get => 42; set { throw new NotSupportedException(); } }   // Fixed
+    int AutoSetPropWithGet { get; set; }             // Compliant, auto-implemented, so not-empty
+
+    class Base
+    {
+        protected virtual int VirtualEmptyInitProp { init { } }  // Compliant, virtual
+    }
+
+    class Inherited : Base
+    {
+        protected override int VirtualEmptyInitProp { init { throw new NotSupportedException(); } } // Fixed
+    }
+
+    class Hidden : Base
+    {
+        protected new int VirtualEmptyInitProp { init { throw new NotSupportedException(); } }      // Fixed
+    }
+}