Implement code fix support for SA1208 with file-scoped namespaces

Author: sharwell

StyleCop.Analyzers/StyleCop.Analyzers.CodeFixes/OrderingRules/UsingCodeFixProvider.SourceMap.cs

@@ -10,6 +10,7 @@ namespace StyleCop.Analyzers.OrderingRules
     using Microsoft.CodeAnalysis;
     using Microsoft.CodeAnalysis.CSharp;
     using Microsoft.CodeAnalysis.CSharp.Syntax;
+    using StyleCop.Analyzers.Lightup;
 
     /// <summary>
     /// Implements a code fix for all misaligned using statements.
@@ -123,12 +124,12 @@ internal TreeTextSpan GetContainingSpan(SyntaxNode node)
 
             private static void ProcessNodeMembers(TreeTextSpan.Builder builder, SyntaxList<MemberDeclarationSyntax> members)
             {
-                foreach (var namespaceDeclaration in members.OfType<NamespaceDeclarationSyntax>())
+                foreach (var namespaceDeclaration in members.Where(member => BaseNamespaceDeclarationSyntaxWrapper.IsInstance(member)))
                 {
                     var childBuilder = builder.AddChild(namespaceDeclaration.FullSpan.Start);
                     childBuilder.SetEnd(namespaceDeclaration.FullSpan.End);
 
-                    ProcessNodeMembers(childBuilder, namespaceDeclaration.Members);
+                    ProcessNodeMembers(childBuilder, ((BaseNamespaceDeclarationSyntaxWrapper)namespaceDeclaration).Members);
                 }
             }
 

StyleCop.Analyzers/StyleCop.Analyzers.CodeFixes/OrderingRules/UsingCodeFixProvider.UsingsSorter.cs

@@ -467,10 +467,10 @@ private bool StartsWithSystemUsingDirectiveIdentifier(NameSyntax name)
 
             private void ProcessMembers(SyntaxList<MemberDeclarationSyntax> members)
             {
-                foreach (var namespaceDeclaration in members.OfType<NamespaceDeclarationSyntax>())
+                foreach (var namespaceDeclaration in members.Where(member => BaseNamespaceDeclarationSyntaxWrapper.IsInstance(member)))
                 {
-                    this.ProcessUsingDirectives(namespaceDeclaration.Usings);
-                    this.ProcessMembers(namespaceDeclaration.Members);
+                    this.ProcessUsingDirectives(((BaseNamespaceDeclarationSyntaxWrapper)namespaceDeclaration).Usings);
+                    this.ProcessMembers(((BaseNamespaceDeclarationSyntaxWrapper)namespaceDeclaration).Members);
                 }
             }
 

StyleCop.Analyzers/StyleCop.Analyzers.CodeFixes/OrderingRules/UsingCodeFixProvider.cs

@@ -16,6 +16,7 @@ namespace StyleCop.Analyzers.OrderingRules
     using Microsoft.CodeAnalysis.CSharp;
     using Microsoft.CodeAnalysis.CSharp.Syntax;
     using StyleCop.Analyzers.Helpers;
+    using StyleCop.Analyzers.Lightup;
     using StyleCop.Analyzers.Settings.ObjectModel;
 
     /// <summary>
@@ -134,7 +135,7 @@ private static string DetermineIndentation(CompilationUnitSyntax compilationUnit
 
             if (usingDirectivesPlacement == UsingDirectivesPlacement.InsideNamespace)
             {
-                var rootNamespace = compilationUnit.Members.OfType<NamespaceDeclarationSyntax>().First();
+                var rootNamespace = compilationUnit.Members.First(member => BaseNamespaceDeclarationSyntaxWrapper.IsInstance(member));
                 var indentationLevel = IndentationHelper.GetIndentationSteps(indentationSettings, rootNamespace);
                 usingsIndentation = IndentationHelper.GenerateIndentationString(indentationSettings, indentationLevel + 1);
             }
@@ -185,9 +186,9 @@ private static int CountNamespaces(SyntaxList<MemberDeclarationSyntax> members)
         {
             var result = 0;
 
-            foreach (var namespaceDeclaration in members.OfType<NamespaceDeclarationSyntax>())
+            foreach (var namespaceDeclaration in members.Where(member => BaseNamespaceDeclarationSyntaxWrapper.IsInstance(member)))
             {
-                result += 1 + CountNamespaces(namespaceDeclaration.Members);
+                result += 1 + CountNamespaces(((BaseNamespaceDeclarationSyntaxWrapper)namespaceDeclaration).Members);
             }
 
             return result;
@@ -267,7 +268,7 @@ private static int CompareSpanStart(UsingDirectiveSyntax left, UsingDirectiveSyn
 
         private static SyntaxNode AddUsingsToNamespace(SyntaxNode newSyntaxRoot, UsingsSorter usingsHelper, string usingsIndentation, bool hasConditionalDirectives)
         {
-            var rootNamespace = ((CompilationUnitSyntax)newSyntaxRoot).Members.OfType<NamespaceDeclarationSyntax>().First();
+            var rootNamespace = (BaseNamespaceDeclarationSyntaxWrapper)((CompilationUnitSyntax)newSyntaxRoot).Members.First(member => BaseNamespaceDeclarationSyntaxWrapper.IsInstance(member));
             var withTrailingBlankLine = hasConditionalDirectives || rootNamespace.Members.Any() || rootNamespace.Externs.Any();
 
             var groupedUsings = usingsHelper.GenerateGroupedUsings(TreeTextSpan.Empty, usingsIndentation, withTrailingBlankLine, qualifyNames: false);

StyleCop.Analyzers/StyleCop.Analyzers.Test.CSharp10/OrderingRules/SA1208CSharp10UnitTests.cs

@@ -14,6 +14,7 @@ namespace StyleCop.Analyzers.Test.CSharp10.OrderingRules
     public class SA1208CSharp10UnitTests : SA1208CSharp9UnitTests
     {
         [Fact]
+        [WorkItem(3437, "https://github.com/DotNetAnalyzers/StyleCopAnalyzers/issues/3437")]
         public async Task TestWhenSystemUsingDirectivesAreNotOnTopInFileScopedNamespaceAsync()
         {
             await new CSharpTest
@@ -26,20 +27,36 @@ public async Task TestWhenSystemUsingDirectivesAreNotOnTopInFileScopedNamespaceA
 namespace Test;
 
 using Xyz;
+{|#0:using System;|}
+{|#1:using System.IO;|}
+using AnotherNamespace;
+{|#2:using System.Threading.Tasks;|}
+
+class A
+{
+}",
+                },
+                FixedSources =
+                {
+                    "namespace Xyz {}",
+                    "namespace AnotherNamespace {}",
+                    @"
+namespace Test;
 using System;
 using System.IO;
-using AnotherNamespace;
 using System.Threading.Tasks;
+using AnotherNamespace;
+using Xyz;
 
 class A
 {
 }",
                 },
                 ExpectedDiagnostics =
                 {
-                    Diagnostic().WithLocation("/0/Test2.cs", 5, 1).WithArguments("System", "Xyz"),
-                    Diagnostic().WithLocation("/0/Test2.cs", 6, 1).WithArguments("System.IO", "Xyz"),
-                    Diagnostic().WithLocation("/0/Test2.cs", 8, 1).WithArguments("System.Threading.Tasks", "Xyz"),
+                    Diagnostic().WithLocation(0).WithArguments("System", "Xyz"),
+                    Diagnostic().WithLocation(1).WithArguments("System.IO", "Xyz"),
+                    Diagnostic().WithLocation(2).WithArguments("System.Threading.Tasks", "Xyz"),
                 },
             }.RunAsync(CancellationToken.None).ConfigureAwait(false);
         }