Fix analyzer RCS0010 (#1620)

Author: josefpihrt

ChangeLog.md

@@ -11,6 +11,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 - Fix analyzer [RCS1229](https://josefpihrt.github.io/docs/roslynator/analyzers/RCS1229) ([PR](https://github.com/dotnet/roslynator/pull/1618))
 - Fix analyzer [RCS1174](https://josefpihrt.github.io/docs/roslynator/analyzers/RCS1174) ([PR](https://github.com/dotnet/roslynator/pull/1619))
+- Fix analyzer [RCS0010](https://josefpihrt.github.io/docs/roslynator/analyzers/RCS0010) ([PR](https://github.com/dotnet/roslynator/pull/1620))
 
 ### Added
 

src/Formatting.Analyzers/CSharp/BlankLineBetweenDeclarationsAnalyzer.cs

@@ -48,7 +48,12 @@ public override void Initialize(AnalysisContext context)
             SyntaxKind.InterfaceDeclaration);
 
         context.RegisterSyntaxNodeAction(f => AnalyzeCompilationUnit(f), SyntaxKind.CompilationUnit);
-        context.RegisterSyntaxNodeAction(f => AnalyzeNamespaceDeclaration(f), SyntaxKind.NamespaceDeclaration);
+        context.RegisterSyntaxNodeAction(
+            f => AnalyzeNamespaceDeclaration(f),
+#if ROSLYN_4_0
+            SyntaxKind.FileScopedNamespaceDeclaration,
+#endif
+            SyntaxKind.NamespaceDeclaration);
         context.RegisterSyntaxNodeAction(f => AnalyzeEnumDeclaration(f), SyntaxKind.EnumDeclaration);
     }
 
@@ -61,8 +66,11 @@ private static void AnalyzeCompilationUnit(SyntaxNodeAnalysisContext context)
 
     private static void AnalyzeNamespaceDeclaration(SyntaxNodeAnalysisContext context)
     {
+#if ROSLYN_4_0
+        var namespaceDeclaration = (BaseNamespaceDeclarationSyntax)context.Node;
+#else
         var namespaceDeclaration = (NamespaceDeclarationSyntax)context.Node;
-
+#endif
         Analyze(context, namespaceDeclaration.Members);
     }
 

src/Tests/Formatting.Analyzers.Tests/RCS0010AddBlankLineBetweenDeclarationsTests.cs

@@ -162,6 +162,35 @@ enum E
 ");
     }
 
+    [Fact, Trait(Traits.Analyzer, DiagnosticIdentifiers.AddBlankLineBetweenDeclarations)]
+    public async Task Test_FileScopedNamespace()
+    {
+        await VerifyDiagnosticAndFixAsync("""
+namespace N;
+
+class Foo
+{
+  void M() { }
+}[|
+|]enum Bar
+{
+  A = 0
+}
+""", """
+namespace N;
+
+class Foo
+{
+  void M() { }
+}
+
+enum Bar
+{
+  A = 0
+}
+""");
+    }
+
     [Fact, Trait(Traits.Analyzer, DiagnosticIdentifiers.AddBlankLineBetweenDeclarations)]
     public async Task TestNoDiagnostic_MemberDeclaration_SingleLine()
     {