Check UsedImplicitlyAttribute (RCS1074) (dotnet#968)

Haarmees · Oct 30, 2023 · ed98184 · ed98184
1 parent 6875799
commit ed98184
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Showing 3 changed files with 66 additions and 15 deletions.
diff --git a/ChangeLog.md b/ChangeLog.md
@@ -37,6 +37,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - [CLI] Include compiler diagnostics in the xml output file of the `roslynator analyze` command ([#964](https://github.com/JosefPihrt/Roslynator/pull/964) by @PeterKaszab).
 - Do not simplify 'default' expression if the type is inferred ([RCS1244](https://github.com/JosefPihrt/Roslynator/blob/main/docs/analyzers/RCS1244.md)) ([#966](https://github.com/josefpihrt/roslynator/pull/966).
 - Use explicit type from lambda expression ([RCS1008](https://github.com/JosefPihrt/Roslynator/blob/main/docs/analyzers/RCS1008.md)) ([#967](https://github.com/josefpihrt/roslynator/pull/967).
+- Do not remove constructor if it is decorated with 'UsedImplicitlyAttribute' ([RCS1074](https://github.com/JosefPihrt/Roslynator/blob/main/docs/analyzers/RCS1074.md)) ([#968](https://github.com/josefpihrt/roslynator/pull/968).
 
 -----
 <!-- Content below does not adhere to 'Keep a Changelog' format -->

diff --git a/src/Analyzers/CSharp/Analysis/RemoveRedundantConstructorAnalyzer.cs b/src/Analyzers/CSharp/Analysis/RemoveRedundantConstructorAnalyzer.cs
@@ -1,19 +1,19 @@
 // Copyright (c) Josef Pihrt and Contributors. Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
-using System;
 using System.Collections.Immutable;
 using System.Linq;
 using Microsoft.CodeAnalysis;
 using Microsoft.CodeAnalysis.CSharp;
 using Microsoft.CodeAnalysis.CSharp.Syntax;
 using Microsoft.CodeAnalysis.Diagnostics;
-using Roslynator.CSharp.Syntax;
 
 namespace Roslynator.CSharp.Analysis
 {
     [DiagnosticAnalyzer(LanguageNames.CSharp)]
     public sealed class RemoveRedundantConstructorAnalyzer : BaseDiagnosticAnalyzer
     {
+        private static readonly MetadataName _usedImplicitlyAttribute = MetadataName.Parse("JetBrains.Annotations.UsedImplicitlyAttribute");
+
         private static ImmutableArray<DiagnosticDescriptor> _supportedDiagnostics;
 
         public override ImmutableArray<DiagnosticDescriptor> SupportedDiagnostics
@@ -63,27 +63,24 @@ private static void AnalyzeConstructorDeclaration(SyntaxNodeAnalysisContext cont
                 return;
             }
 
-            if (!IsSingleInstanceConstructor(constructor))
+            if (constructor.HasDocumentationComment())
                 return;
 
-            if (constructor.HasDocumentationComment())
+            IMethodSymbol symbol = context.SemanticModel.GetDeclaredSymbol(constructor, context.CancellationToken);
+
+            if (symbol?.Kind != SymbolKind.Method)
                 return;
 
-            if (!constructor.DescendantTrivia(constructor.Span).All(f => f.IsWhitespaceOrEndOfLineTrivia()))
+            if (symbol.ContainingType.InstanceConstructors.SingleOrDefault(shouldThrow: false) != symbol)
                 return;
 
-            DiagnosticHelpers.ReportDiagnostic(context, DiagnosticRules.RemoveRedundantConstructor, constructor);
-        }
+            if (symbol.HasAttribute(_usedImplicitlyAttribute))
+                return;
 
-        private static bool IsSingleInstanceConstructor(ConstructorDeclarationSyntax constructor)
-        {
-            MemberDeclarationListInfo info = SyntaxInfo.MemberDeclarationListInfo(constructor.Parent);
+            if (!constructor.DescendantTrivia(constructor.Span).All(f => f.IsWhitespaceOrEndOfLineTrivia()))
+                return;
 
-            return info.Success
-                && info
-                    .Members
-                    .OfType<ConstructorDeclarationSyntax>()
-                    .All(f => f.Equals(constructor) || f.Modifiers.Contains(SyntaxKind.StaticKeyword));
+            DiagnosticHelpers.ReportDiagnostic(context, DiagnosticRules.RemoveRedundantConstructor, constructor);
         }
     }
 }
diff --git a/src/Tests/Analyzers.Tests/RCS1074RemoveRedundantConstructorTests.cs b/src/Tests/Analyzers.Tests/RCS1074RemoveRedundantConstructorTests.cs
@@ -0,0 +1,53 @@
+// Copyright (c) Josef Pihrt and Contributors. Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+using System.Threading.Tasks;
+using Microsoft.CodeAnalysis;
+using Roslynator.CSharp.CodeFixes;
+using Roslynator.Testing.CSharp;
+using Xunit;
+
+namespace Roslynator.CSharp.Analysis.Tests
+{
+    public class RCS1074RemoveRedundantConstructorTests : AbstractCSharpDiagnosticVerifier<RemoveRedundantConstructorAnalyzer, ConstructorDeclarationCodeFixProvider>
+    {
+        public override DiagnosticDescriptor Descriptor { get; } = DiagnosticRules.RemoveRedundantConstructor;
+
+        [Fact, Trait(Traits.Analyzer, DiagnosticIdentifiers.RemoveRedundantConstructor)]
+        public async Task Test_SingleInstanceConstructor()
+        {
+            await VerifyDiagnosticAndFixAsync(@"
+class C
+{
+    [|public C()
+    {
+    }|]
+}
+", @"
+class C
+{
+}
+");
+        }
+
+        [Fact, Trait(Traits.Analyzer, DiagnosticIdentifiers.RemoveRedundantConstructor)]
+        public async Task TestNoDiagnostic_UsedImplicitlyAttribute()
+        {
+            await VerifyNoDiagnosticAsync(@"
+class C
+{
+    [JetBrains.Annotations.UsedImplicitly]
+    public C()
+    {
+    }
+}
+
+namespace JetBrains.Annotations
+{
+    public class UsedImplicitlyAttribute : System.Attribute
+    {
+    }
+}
+");
+        }
+    }
+}