Update SA1206 to recognize modifier "file"

#3589

Author: bjornhellander

StyleCop.Analyzers/StyleCop.Analyzers.Test.CSharp11/OrderingRules/SA1206CSharp11CodeFixProviderUnitTests.cs

@@ -3,9 +3,25 @@
 
 namespace StyleCop.Analyzers.Test.CSharp11.OrderingRules
 {
+    using System.Threading;
+    using System.Threading.Tasks;
     using StyleCop.Analyzers.Test.CSharp10.OrderingRules;
+    using Xunit;
+    using static StyleCop.Analyzers.Test.Verifiers.StyleCopCodeFixVerifier<
+        StyleCop.Analyzers.OrderingRules.SA1206DeclarationKeywordsMustFollowOrder,
+        StyleCop.Analyzers.OrderingRules.SA1206CodeFixProvider>;
 
     public class SA1206CSharp11CodeFixProviderUnitTests : SA1206CSharp10CodeFixProviderUnitTests
     {
+        [Fact]
+        [WorkItem(3589, "https://github.com/DotNetAnalyzers/StyleCopAnalyzers/issues/3589")]
+        public async Task VerifyFileKeywordReorderingInClassDeclarationAsync()
+        {
+            var testCode = $"static unsafe {{|#0:file|}} class TestClass {{}}";
+            var fixedTestCode = $"file static unsafe class TestClass {{}}";
+
+            var expected = Diagnostic().WithLocation(0).WithArguments("file", "unsafe");
+            await VerifyCSharpFixAsync(testCode, expected, fixedTestCode, CancellationToken.None).ConfigureAwait(false);
+        }
     }
 }

StyleCop.Analyzers/StyleCop.Analyzers.Test.CSharp11/StyleCop.Analyzers.Test.CSharp11.csproj

@@ -17,7 +17,7 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Microsoft.CodeAnalysis.CSharp.Workspaces" Version="4.2.0-4.final" />
+    <PackageReference Include="Microsoft.CodeAnalysis.CSharp.Workspaces" Version="4.4.0" />
     <PackageReference Include="xunit" Version="2.4.1" />
     <PackageReference Include="xunit.runner.visualstudio" Version="2.4.1" PrivateAssets="all" />
   </ItemGroup>

StyleCop.Analyzers/StyleCop.Analyzers/Helpers/ModifierOrderHelper.cs

@@ -7,6 +7,7 @@ namespace StyleCop.Analyzers.OrderingRules
 {
     using Microsoft.CodeAnalysis;
     using Microsoft.CodeAnalysis.CSharp;
+    using StyleCop.Analyzers.Lightup;
 
     internal static class ModifierOrderHelper
     {
@@ -21,7 +22,7 @@ internal enum ModifierType
             None,
 
             /// <summary>
-            /// Represents any of access modifiers, i.e <see langword="public"/>, <see langword="protected"/>, <see langword="internal"/>, <see langword="private"/>.
+            /// Represents any of access modifiers, i.e <see langword="public"/>, <see langword="protected"/>, <see langword="internal"/>, <see langword="private"/>, <see langword="file"/>.
             /// </summary>
             Access,
 
@@ -46,6 +47,7 @@ internal static ModifierType GetModifierType(SyntaxToken modifier)
             case SyntaxKind.ProtectedKeyword:
             case SyntaxKind.InternalKeyword:
             case SyntaxKind.PrivateKeyword:
+            case SyntaxKindEx.FileKeyword:
                 result = ModifierType.Access;
                 break;
 

StyleCop.Analyzers/StyleCop.Analyzers/Lightup/SyntaxKindEx.cs

@@ -14,6 +14,7 @@ internal static class SyntaxKindEx
         public const SyntaxKind NotKeyword = (SyntaxKind)8440;
         public const SyntaxKind ManagedKeyword = (SyntaxKind)8445;
         public const SyntaxKind UnmanagedKeyword = (SyntaxKind)8446;
+        public const SyntaxKind FileKeyword = (SyntaxKind)8449;
         public const SyntaxKind NullableKeyword = (SyntaxKind)8486;
         public const SyntaxKind EnableKeyword = (SyntaxKind)8487;
         public const SyntaxKind WarningsKeyword = (SyntaxKind)8488;