Add IsFileLocal lightup, use it in CA1708

src/NetAnalyzers/Core/Microsoft.CodeQuality.Analyzers/ApiDesignGuidelines/IdentifiersShouldDifferByMoreThanCase.cs

@@ -1,4 +1,4 @@
-// Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the MIT license.  See License.txt in the project root for license information.
+// Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the MIT license.  See License.txt in the project root for license information.
 
 using System;
 using System.Collections.Generic;
@@ -8,6 +8,7 @@
 using Microsoft.CodeAnalysis;
 using Analyzer.Utilities;
 using Analyzer.Utilities.Extensions;
+using Analyzer.Utilities.Lightup;
 using Analyzer.Utilities.PooledObjects;
 
 namespace Microsoft.CodeQuality.Analyzers.ApiDesignGuidelines
@@ -54,7 +55,8 @@ private static void AnalyzeCompilation(CompilationAnalysisContext context)
 
             IEnumerable<INamedTypeSymbol> globalTypes = context.Compilation.GlobalNamespace.GetTypeMembers().Where(item =>
                     Equals(item.ContainingAssembly, context.Compilation.Assembly) &&
-                    MatchesConfiguredVisibility(item, context.Options, context.Compilation));
+                    MatchesConfiguredVisibility(item, context.Options, context.Compilation) &&
+                    !IsFileLocalWrapper.FromSymbol(item).IsFileLocal);
 
             CheckTypeNames(globalTypes, context);
             CheckNamespaceMembers(globalNamespaces, context);
@@ -96,8 +98,9 @@ private static void CheckNamespaceMembers(IEnumerable<INamespaceSymbol> namespac
             {
                 // Get all the potentially externally visible types in the namespace
                 IEnumerable<INamedTypeSymbol> typeMembers = @namespace.GetTypeMembers().Where(item =>
-                    Equals(item.ContainingAssembly, context.Compilation.Assembly) &&
-                    MatchesConfiguredVisibility(item, context.Options, context.Compilation));
+                Equals(item.ContainingAssembly, context.Compilation.Assembly) &&
+                MatchesConfiguredVisibility(item, context.Options, context.Compilation) &&
+                !IsFileLocalWrapper.FromSymbol(item).IsFileLocal);
 
                 if (typeMembers.Any())
                 {

src/NetAnalyzers/UnitTests/Microsoft.CodeQuality.Analyzers/ApiDesignGuidelines/IdentifiersShouldDifferByMoreThanCaseTests.cs

@@ -1,4 +1,4 @@
-// Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the MIT license.  See License.txt in the project root for license information.
+// Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the MIT license.  See License.txt in the project root for license information.
 
 using System;
 using System.Linq;
@@ -142,6 +142,57 @@ public partial class F
             }.RunAsync();
         }
 
+        [Fact]
+        public async Task FileScopedTypesInNamespaceAsync()
+        {
+            string fileWithClass = """
+                namespace N;
+
+                file class C
+                {
+                }
+                """;
+
+            await new VerifyCS.Test
+            {
+                TestState =
+                {
+                    Sources =
+                    {
+                        fileWithClass,
+                        fileWithClass
+                    }
+                },
+                LanguageVersion = CodeAnalysis.CSharp.LanguageVersion.CSharp11,
+                ReferenceAssemblies = ReferenceAssemblies.Net.Net70
+            }.RunAsync();
+        }
+
+        [Fact]
+        public async Task FileScopedTypesGlobalAsync()
+        {
+            string fileWithClass = """
+                file class C
+                {
+                }
+                """;
+
+            await new VerifyCS.Test
+            {
+                TestState =
+                {
+                    Sources =
+                    {
+                        fileWithClass,
+                        fileWithClass
+                    }
+                },
+                LanguageVersion = CodeAnalysis.CSharp.LanguageVersion.CSharp11,
+                ReferenceAssemblies = ReferenceAssemblies.Net.Net70
+            }.RunAsync();
+        }
+
+
         #endregion
 
         #region Type Level

src/Utilities/Compiler/Analyzer.Utilities.projitems

@@ -66,6 +66,7 @@
     <Compile Include="$(MSBuildThisFileDirectory)Extensions\WellKnownDiagnosticTagsExtensions.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Index.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)IsExternalInit.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)Lightup\IsFileLocalWrapper.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Lightup\IOperationWrapper.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Lightup\IFunctionPointerInvocationOperationWrapper.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Lightup\IUtf8StringOperationWrapper.cs" />

src/Utilities/Compiler/Lightup/IsFileLocalWrapper.cs

@@ -0,0 +1,35 @@
+// Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the MIT license.  See License.txt in the project root for license information.
+
+#if HAS_IOPERATION
+
+namespace Analyzer.Utilities.Lightup
+{
+    using System;
+    using System.Diagnostics.CodeAnalysis;
+    using System.Reflection;
+    using Microsoft.CodeAnalysis;
+
+    [SuppressMessage("Performance", "CA1815:Override equals and operator equals on value types", Justification = "Not a comparable instance.")]
+    internal readonly struct IsFileLocalWrapper
+    {
+        private static readonly PropertyInfo? PropertyAccessor = typeof(INamedTypeSymbol).GetProperty("IsFileLocal", BindingFlags.Public | BindingFlags.Instance);
+
+        private static readonly Func<INamedTypeSymbol, bool> MemberAccessor = PropertyAccessor is null ? _ => false : symbol => (bool)PropertyAccessor.GetValue(symbol);
+
+        public INamedTypeSymbol WrappedSymbol { get; }
+
+        private IsFileLocalWrapper(INamedTypeSymbol symbol)
+        {
+            WrappedSymbol = symbol;
+        }
+
+        public static IsFileLocalWrapper FromSymbol(INamedTypeSymbol symbol)
+        {
+            return new IsFileLocalWrapper(symbol);
+        }
+
+        public bool IsFileLocal => MemberAccessor(WrappedSymbol);
+    }
+}
+
+#endif