Improve analyzer RCS1259 (#1268)

Author: josefpihrt

ChangeLog.md

@@ -14,11 +14,12 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Fixed
 
-- Fix [RCS1228](https://josefpihrt.github.io/docs/roslynator/analyzers/RCS1228) ([PR](https://github.com/dotnet/roslynator/pull/1249))
-- Fix [RCS1213](https://josefpihrt.github.io/docs/roslynator/analyzers/RCS1213) ([PR](https://github.com/dotnet/roslynator/pull/1254))
-- Fix [RCS1055](https://josefpihrt.github.io/docs/roslynator/analyzers/RCS1055) ([PR](https://github.com/dotnet/roslynator/pull/1253))
-- Fix [RCS1196](https://josefpihrt.github.io/docs/roslynator/analyzers/RCS1196) ([PR](https://github.com/dotnet/roslynator/pull/1235))
-- Fix [RCS1257](https://josefpihrt.github.io/docs/roslynator/analyzers/RCS1257) ([PR](https://github.com/dotnet/roslynator/pull/1264))
+- Fix analyzer [RCS1228](https://josefpihrt.github.io/docs/roslynator/analyzers/RCS1228) ([PR](https://github.com/dotnet/roslynator/pull/1249))
+- Fix analyzer [RCS1213](https://josefpihrt.github.io/docs/roslynator/analyzers/RCS1213) ([PR](https://github.com/dotnet/roslynator/pull/1254))
+- Fix analyzer [RCS1055](https://josefpihrt.github.io/docs/roslynator/analyzers/RCS1055) ([PR](https://github.com/dotnet/roslynator/pull/1253))
+- Fix analyzer [RCS1196](https://josefpihrt.github.io/docs/roslynator/analyzers/RCS1196) ([PR](https://github.com/dotnet/roslynator/pull/1235))
+- Fix analyzer [RCS1257](https://josefpihrt.github.io/docs/roslynator/analyzers/RCS1257) ([PR](https://github.com/dotnet/roslynator/pull/1264))
+- Fix analyzer [RCS1259](https://josefpihrt.github.io/docs/roslynator/analyzers/RCS1259) ([PR](https://github.com/dotnet/roslynator/pull/1268))
 
 ## [4.6.2] - 2023-11-10
 

src/Analyzers.CodeFixes/CSharp/CodeFixes/NamespaceDeclarationCodeFixProvider.cs

@@ -41,7 +41,7 @@ public override async Task RegisterCodeFixesAsync(CodeFixContext context)
                     {
                         CodeAction codeAction = CodeAction.Create(
                             "Remove empty namespace declaration",
-                            ct => RemoveEmptyNamespaceDeclarationRefactoring.RefactorAsync(context.Document, namespaceDeclaration, ct),
+                            ct => context.Document.RemoveNodeAsync(namespaceDeclaration, ct),
                             GetEquivalenceKey(diagnostic));
 
                         context.RegisterCodeFix(codeAction, diagnostic);

src/Analyzers.CodeFixes/CSharp/CodeFixes/RemoveEmptySyntaxCodeFixProvider.cs

@@ -43,6 +43,7 @@ public override async Task RegisterCodeFixesAsync(CodeFixContext context)
                     case SyntaxKind.EmptyStatement:
                     case SyntaxKind.FinallyClause:
                     case SyntaxKind.NamespaceDeclaration:
+                    case SyntaxKind.FileScopedNamespaceDeclaration:
                     case SyntaxKind.ObjectCreationExpression:
                     case SyntaxKind.RegionDirectiveTrivia:
                         return true;
@@ -100,11 +101,11 @@ public override async Task RegisterCodeFixesAsync(CodeFixContext context)
                     context.RegisterCodeFix(codeAction, diagnostic);
                     break;
                 }
-            case NamespaceDeclarationSyntax namespaceDeclaration:
+            case BaseNamespaceDeclarationSyntax namespaceDeclaration:
                 {
                     CodeAction codeAction = CodeAction.Create(
                         "Remove empty namespace declaration",
-                        ct => RemoveEmptyNamespaceDeclarationRefactoring.RefactorAsync(document, namespaceDeclaration, ct),
+                        ct => document.RemoveNodeAsync(namespaceDeclaration, ct),
                         GetEquivalenceKey(diagnostic));
 
                     context.RegisterCodeFix(codeAction, diagnostic);

src/Analyzers.CodeFixes/CSharp/Refactorings/RemoveEmptyNamespaceDeclarationRefactoring.cs

@@ -34,6 +34,7 @@ public override void Initialize(AnalysisContext context)
         context.RegisterSyntaxNodeAction(f => AnalyzeFinallyClause(f), SyntaxKind.FinallyClause);
         context.RegisterSyntaxNodeAction(f => AnalyzeObjectCreationExpression(f), SyntaxKind.ObjectCreationExpression);
         context.RegisterSyntaxNodeAction(f => AnalyzeNamespaceDeclaration(f), SyntaxKind.NamespaceDeclaration);
+        context.RegisterSyntaxNodeAction(f => AnalyzeFileScopedNamespaceDeclaration(f), SyntaxKind.FileScopedNamespaceDeclaration);
         context.RegisterSyntaxNodeAction(f => AnalyzeRegionDirective(f), SyntaxKind.RegionDirectiveTrivia);
         context.RegisterSyntaxNodeAction(f => AnalyzeEmptyStatement(f), SyntaxKind.EmptyStatement);
     }
@@ -180,6 +181,16 @@ private static void AnalyzeNamespaceDeclaration(SyntaxNodeAnalysisContext contex
         ReportDiagnostic(context, declaration, "namespace declaration");
     }
 
+    private static void AnalyzeFileScopedNamespaceDeclaration(SyntaxNodeAnalysisContext context)
+    {
+        var declaration = (FileScopedNamespaceDeclarationSyntax)context.Node;
+
+        if (declaration.Members.Any())
+            return;
+
+        ReportDiagnostic(context, declaration, "namespace declaration");
+    }
+
     private static void AnalyzeRegionDirective(SyntaxNodeAnalysisContext context)
     {
         var regionDirective = (RegionDirectiveTriviaSyntax)context.Node;

src/Analyzers/CSharp/Analysis/RemoveEmptySyntaxAnalyzer.cs

@@ -423,6 +423,14 @@ class C
 ");
     }
 
+    [Fact, Trait(Traits.Analyzer, DiagnosticIdentifiers.RemoveEmptySyntax)]
+    public async Task Test_FileScopedNamespace()
+    {
+        await VerifyDiagnosticAndFixAsync(@"
+[|namespace N1;|]
+", "");
+    }
+
     [Fact, Trait(Traits.Analyzer, DiagnosticIdentifiers.RemoveEmptySyntax)]
     public async Task Test_RegionDirective()
     {
@@ -492,4 +500,16 @@ void M(bool p)
 }
 ", options: Options.AddAllowedCompilerDiagnosticId("CS0642"));
     }
+
+    [Fact, Trait(Traits.Analyzer, DiagnosticIdentifiers.RemoveEmptySyntax)]
+    public async Task TestNoDiagnostic_FileScopedNamespaceDeclaration()
+    {
+        await VerifyNoDiagnosticAsync(@"
+namespace N1;
+
+class C
+{
+}
+");
+    }
 }