Add sync namespace analyzer

src/Analyzers/CSharp/Analyzers/CSharpAnalyzers.projitems

@@ -19,6 +19,7 @@
     <Compile Include="$(MSBuildThisFileDirectory)AddBraces\CSharpAddBracesDiagnosticAnalyzer.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)AddRequiredParentheses\CSharpAddRequiredPatternParenthesesDiagnosticAnalyzer.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)ConvertTypeofToNameof\CSharpConvertTypeOfToNameOfDiagnosticAnalyzer.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)MatchFolderAndNamespace\CSharpMatchFolderAndNamespaceDiagnosticAnalyzer.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)RemoveRedundantEquality\CSharpRemoveRedundantEqualityDiagnosticAnalyzer.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)RemoveUnnecessaryDiscardDesignation\CSharpRemoveUnnecessaryDiscardDesignationDiagnosticAnalyzer.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)RemoveUnnecessarySuppressions\CSharpRemoveUnnecessaryPragmaSuppressionsDiagnosticAnalyzer.cs" />

src/Analyzers/CSharp/Analyzers/MatchFolderAndNamespace/CSharpMatchFolderAndNamespaceDiagnosticAnalyzer.cs

@@ -0,0 +1,23 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using Microsoft.CodeAnalysis.CSharp.Syntax;
+using Microsoft.CodeAnalysis.Analyzers.MatchFolderAndNamespace;
+using Microsoft.CodeAnalysis.LanguageServices;
+using Microsoft.CodeAnalysis.Diagnostics;
+using Microsoft.CodeAnalysis.CSharp.LanguageServices;
+
+namespace Microsoft.CodeAnalysis.CSharp.Analyzers.MatchFolderAndNamespace
+{
+    [DiagnosticAnalyzer(LanguageNames.CSharp)]
+    internal class CSharpMatchFolderAndNamespaceDiagnosticAnalyzer : AbstractMatchFolderAndNamespaceDiagnosticAnalyzer<NamespaceDeclarationSyntax>
+    {
+        protected override ISyntaxFacts GetSyntaxFacts() => CSharpSyntaxFacts.Instance;
+
+        protected override void InitializeWorker(AnalysisContext context)
+        {
+            context.RegisterSyntaxNodeAction(AnalyzeNamespaceNode, SyntaxKind.NamespaceDeclaration);
+        }
+    }
+}

src/Analyzers/CSharp/CodeFixes/CSharpCodeFixes.projitems

@@ -25,6 +25,7 @@
     <Compile Include="$(MSBuildThisFileDirectory)MakeFieldReadonly\CSharpMakeFieldReadonlyCodeFixProvider.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)MakeStructFieldsWritable\CSharpMakeStructFieldsWritableCodeFixProvider.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)MisplacedUsingDirectives\MisplacedUsingDirectivesCodeFixProvider.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)MatchFolderAndNamespace\CSharpChangeNamespaceToMatchFolderCodeFixProvider.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)OrderModifiers\CSharpOrderModifiersCodeFixProvider.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)PopulateSwitch\CSharpPopulateSwitchExpressionCodeFixProvider.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)PopulateSwitch\CSharpPopulateSwitchStatementCodeFixProvider.cs" />

src/Analyzers/CSharp/CodeFixes/MatchFolderAndNamespace/CSharpChangeNamespaceToMatchFolderCodeFixProvider.cs

@@ -0,0 +1,22 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System;
+using System.Composition;
+using Microsoft.CodeAnalysis.CodeFixes;
+using Microsoft.CodeAnalysis.CodeFixes.MatchFolderAndNamespace;
+using Microsoft.CodeAnalysis.Host.Mef;
+
+namespace Microsoft.CodeAnalysis.CSharp.CodeFixes.MatchFolderAndNamespace
+{
+    [ExportCodeFixProvider(LanguageNames.CSharp, Name = PredefinedCodeFixProviderNames.ChangeNamespaceToMatchFolder), Shared]
+    internal class CSharpChangeNamespaceToMatchFolderCodeFixProvider : AbstractChangeNamespaceToMatchFolderCodeFixProvider
+    {
+        [ImportingConstructor]
+        [Obsolete(MefConstruction.ImportingConstructorMessage, error: true)]
+        public CSharpChangeNamespaceToMatchFolderCodeFixProvider()
+        {
+        }
+    }
+}

src/Analyzers/CSharp/Tests/CSharpAnalyzers.UnitTests.projitems

@@ -9,6 +9,7 @@
     <Import_RootNamespace>Microsoft.CodeAnalysis.CSharp.Analyzers.UnitTests</Import_RootNamespace>
   </PropertyGroup>
   <ItemGroup>
+    <Compile Include="$(MSBuildThisFileDirectory)MatchFolderAndNamespace\CSharpMatchFolderAndNamespaceTests.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)RemoveUnnecessaryDiscardDesignation\RemoveUnnecessaryDiscardDesignationTests.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)AddAccessibilityModifiers\AddAccessibilityModifiersTests.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)AddBraces\AddBracesFixAllTests.cs" />