Add an option to control if unused members shoudl be faded out.

src/Analyzers/Core/Analyzers/RemoveUnusedMembers/AbstractRemoveUnusedMembersDiagnosticAnalyzer.cs

@@ -10,7 +10,6 @@
 using System.Linq;
 using System.Runtime.CompilerServices;
 using System.Threading;
-using Microsoft.CodeAnalysis.CodeQuality;
 using Microsoft.CodeAnalysis.CodeStyle;
 using Microsoft.CodeAnalysis.Diagnostics;
 using Microsoft.CodeAnalysis.LanguageService;
@@ -27,10 +26,9 @@ internal abstract class AbstractRemoveUnusedMembersDiagnosticAnalyzer<
     TIdentifierNameSyntax,
     TTypeDeclarationSyntax,
     TMemberDeclarationSyntax>()
-    : AbstractCodeQualityDiagnosticAnalyzer(
+    : AbstractBuiltInUnnecessaryCodeStyleDiagnosticAnalyzer(
         [s_removeUnusedMembersRule, s_removeUnreadMembersRule],
-        // We want to analyze references in generated code, but not report unused members in generated code.
-        GeneratedCodeAnalysisFlags.Analyze)
+        FadingOptions.FadeOutUnusedMembers)
     where TDocumentationCommentTriviaSyntax : SyntaxNode
     where TIdentifierNameSyntax : SyntaxNode
     where TTypeDeclarationSyntax : TMemberDeclarationSyntax
@@ -44,35 +42,43 @@ internal abstract class AbstractRemoveUnusedMembersDiagnosticAnalyzer<
         memberOptions: SymbolDisplayMemberOptions.IncludeContainingType);
 
     // IDE0051: "Remove unused members" (Symbol is declared but never referenced)
-    private static readonly DiagnosticDescriptor s_removeUnusedMembersRule = CreateDescriptor(
+    private static readonly DiagnosticDescriptor s_removeUnusedMembersRule = CreateDescriptorWithId(
         IDEDiagnosticIds.RemoveUnusedMembersDiagnosticId,
         EnforceOnBuildValues.RemoveUnusedMembers,
+        hasAnyCodeStyleOption: false,
         new LocalizableResourceString(nameof(AnalyzersResources.Remove_unused_private_members), AnalyzersResources.ResourceManager, typeof(AnalyzersResources)),
         new LocalizableResourceString(nameof(AnalyzersResources.Private_member_0_is_unused), AnalyzersResources.ResourceManager, typeof(AnalyzersResources)),
-        hasAnyCodeStyleOption: false, isUnnecessary: true);
+        isUnnecessary: true);
 
     // IDE0052: "Remove unread members" (Value is written and/or symbol is referenced, but the assigned value is never read)
     // Internal for testing
-    internal static readonly DiagnosticDescriptor s_removeUnreadMembersRule = CreateDescriptor(
+    internal static readonly DiagnosticDescriptor s_removeUnreadMembersRule = CreateDescriptorWithId(
         IDEDiagnosticIds.RemoveUnreadMembersDiagnosticId,
         EnforceOnBuildValues.RemoveUnreadMembers,
+        hasAnyCodeStyleOption: false,
         new LocalizableResourceString(nameof(AnalyzersResources.Remove_unread_private_members), AnalyzersResources.ResourceManager, typeof(AnalyzersResources)),
         new LocalizableResourceString(nameof(AnalyzersResources.Private_member_0_can_be_removed_as_the_value_assigned_to_it_is_never_read), AnalyzersResources.ResourceManager, typeof(AnalyzersResources)),
-        hasAnyCodeStyleOption: false, isUnnecessary: true);
+        isUnnecessary: true);
 
     protected abstract ISemanticFacts SemanticFacts { get; }
 
     protected abstract IEnumerable<TTypeDeclarationSyntax> GetTypeDeclarations(INamedTypeSymbol namedType, CancellationToken cancellationToken);
     protected abstract SyntaxList<TMemberDeclarationSyntax> GetMembers(TTypeDeclarationSyntax typeDeclaration);
     protected abstract SyntaxNode GetParentIfSoleDeclarator(SyntaxNode declaration);
 
-    // We need to analyze the whole document even for edits within a method body,
-    // because we might add or remove references to members in executable code.
-    // For example, if we had an unused field with no references, then editing any single method body
-    // to reference this field should clear the unused field diagnostic.
-    // Hence, we need to re-analyze the declarations in the whole file for any edits within the document. 
+    /// <summary>
+    /// We need to analyze the whole document even for edits within a method body, because we might add or remove
+    /// references to members in executable code. For example, if we had an unused field with no references, then
+    /// editing any single method body to reference this field should clear the unused field diagnostic. Hence, we need
+    /// to re-analyze the declarations in the whole file for any edits within the document. 
+    /// </summary>
     public override DiagnosticAnalyzerCategory GetAnalyzerCategory() => DiagnosticAnalyzerCategory.SemanticDocumentAnalysis;
 
+    /// <summary>
+    /// We want to analyze references in generated code, but not report unused members in generated code.
+    /// </summary>
+    protected override GeneratedCodeAnalysisFlags GeneratedCodeAnalysisFlags => GeneratedCodeAnalysisFlags.Analyze;
+
     protected sealed override void InitializeWorker(AnalysisContext context)
         => context.RegisterCompilationStartAction(compilationStartContext
             => CompilationAnalyzer.CreateAndRegisterActions(compilationStartContext, this));

src/Analyzers/VisualBasic/Tests/RemoveUnusedMembers/RemoveUnusedMembersTests.vb

@@ -1621,7 +1621,7 @@ parseOptions:=Nothing,
 compilationOptions:=Nothing,
 options:=Nothing,
 "IDE0051",
-DiagnosticSeverity.Info,
+DiagnosticSeverity.Hidden,
 diagnosticMessage:=String.Format(AnalyzersResources.Private_member_0_is_unused, "C.New"))
         End Function
     End Class

src/EditorFeatures/CSharpTest/QuickInfo/DiagnosticAnalyzerQuickInfoSourceTests.cs

@@ -25,7 +25,7 @@ namespace Microsoft.CodeAnalysis.Editor.CSharp.UnitTests.QuickInfo;
 
 [UseExportProvider]
 [Trait(Traits.Feature, Traits.Features.QuickInfo)]
-public class DiagnosticAnalyzerQuickInfoSourceTests
+public sealed class DiagnosticAnalyzerQuickInfoSourceTests
 {
     [WpfFact, WorkItem("https://github.com/dotnet/roslyn/issues/46604")]
     public async Task ErrorTitleIsShownOnDisablePragma()
@@ -156,26 +156,26 @@ public async Task QuickInfoSuppressMessageAttributeUseCases(string suppressMessa
             ? GetFormattedIDEAnalyzerTitle(51, nameof(AnalyzersResources.Remove_unused_private_members))
             : null;
         await TestAsync(
-@$"
-using System.Diagnostics.CodeAnalysis;
-using SM = System.Diagnostics.CodeAnalysis.SuppressMessageAttribute;
-namespace T
-{{
-    public static class DiagnosticIds
-    {{
-        public const string IDE0051 = ""IDE0051"";
-    }}
+            $$"""
+            using System.Diagnostics.CodeAnalysis;
+            using SM = System.Diagnostics.CodeAnalysis.SuppressMessageAttribute;
+            namespace T
+            {
+                public static class DiagnosticIds
+                {
+                    public const string IDE0051 = "IDE0051";
+                }
 
-    {suppressMessageAttribute}
-    public class C
-    {{
-        private int _i;
-    }}
-}}
-", description, ImmutableArray<TextSpan>.Empty);
+                {{suppressMessageAttribute}}
+                public class C
+                {
+                    private int _i;
+                }
+            }
+            """, description, ImmutableArray<TextSpan>.Empty);
     }
 
-    protected static async Task AssertContentIsAsync(EditorTestWorkspace workspace, Document document, int position, string expectedDescription,
+    private static async Task AssertContentIsAsync(EditorTestWorkspace workspace, Document document, int position, string expectedDescription,
         ImmutableArray<TextSpan> relatedSpans)
     {
         var info = await GetQuickinfo(workspace, document, position);
@@ -194,13 +194,13 @@ private static async Task<QuickInfoItem> GetQuickinfo(EditorTestWorkspace worksp
         return info;
     }
 
-    protected static async Task AssertNoContentAsync(EditorTestWorkspace workspace, Document document, int position)
+    private static async Task AssertNoContentAsync(EditorTestWorkspace workspace, Document document, int position)
     {
         var info = await GetQuickinfo(workspace, document, position);
         Assert.Null(info);
     }
 
-    protected static async Task TestAsync(
+    private static async Task TestAsync(
         string code,
         string expectedDescription,
         ImmutableArray<TextSpan> relatedSpans,
@@ -237,7 +237,7 @@ private static string GetFormattedIDEAnalyzerTitle(int ideDiagnosticId, string n
         return $"IDE{ideDiagnosticId:0000}: {localizable}";
     }
 
-    protected static Task TestInClassAsync(string code, string expectedDescription, params TextSpan[] relatedSpans)
+    private static Task TestInClassAsync(string code, string expectedDescription, params TextSpan[] relatedSpans)
         => TestAsync(
             $$"""
             class C
@@ -246,7 +246,7 @@ class C
             }
             """, expectedDescription, relatedSpans.ToImmutableArray());
 
-    protected static Task TestInMethodAsync(string code, string expectedDescription, params TextSpan[] relatedSpans)
+    private static Task TestInMethodAsync(string code, string expectedDescription, params TextSpan[] relatedSpans)
         => TestInClassAsync(
             $$"""
             void M()

src/VisualStudio/CSharp/Impl/Options/AdvancedOptionPageControl.xaml

@@ -194,6 +194,8 @@
                 <StackPanel>
                     <CheckBox x:Name="Fade_out_unused_usings"
                               Content="{x:Static local:AdvancedOptionPageStrings.Option_Fade_out_unused_usings}" />
+                    <CheckBox x:Name="Fade_out_unused_members"
+                              Content="{x:Static local:AdvancedOptionPageStrings.Option_Fade_out_unused_members}" />
                     <CheckBox x:Name="Fade_out_unreachable_code"
                               Content="{x:Static local:AdvancedOptionPageStrings.Option_Fade_out_unreachable_code}" />
                 </StackPanel>

src/VisualStudio/CSharp/Impl/Options/AdvancedOptionPageControl.xaml.cs

@@ -129,6 +129,7 @@ public AdvancedOptionPageControl(OptionStore optionStore) : base(optionStore)
 
             // Fading
             BindToOption(Fade_out_unused_usings, FadingOptions.FadeOutUnusedImports, LanguageNames.CSharp);
+            BindToOption(Fade_out_unused_members, FadingOptions.FadeOutUnusedMembers, LanguageNames.CSharp);
             BindToOption(Fade_out_unreachable_code, FadingOptions.FadeOutUnreachableCode, LanguageNames.CSharp);
 
             // Block Structure Guides

src/VisualStudio/CSharp/Impl/Options/AdvancedOptionPageStrings.cs

@@ -268,6 +268,9 @@ public static string Option_Fading
         public static string Option_Fade_out_unused_usings
             => CSharpVSResources.Fade_out_unused_usings;
 
+        public static string Option_Fade_out_unused_members
+            => ServicesVSResources.Fade_out_unused_members;
+
         public static string Option_Fade_out_unreachable_code
             => ServicesVSResources.Fade_out_unreachable_code;
 

src/VisualStudio/CSharp/Impl/Options/AutomationObject/AutomationObject.Fading.cs

@@ -4,20 +4,25 @@
 
 using Microsoft.CodeAnalysis.CodeStyle;
 
-namespace Microsoft.VisualStudio.LanguageServices.CSharp.Options
+namespace Microsoft.VisualStudio.LanguageServices.CSharp.Options;
+
+public partial class AutomationObject
 {
-    public partial class AutomationObject
+    public int Fading_FadeOutUnreachableCode
+    {
+        get { return GetBooleanOption(FadingOptions.FadeOutUnreachableCode); }
+        set { SetBooleanOption(FadingOptions.FadeOutUnreachableCode, value); }
+    }
+
+    public int Fading_FadeOutUnusedImports
     {
-        public int Fading_FadeOutUnreachableCode
-        {
-            get { return GetBooleanOption(FadingOptions.FadeOutUnreachableCode); }
-            set { SetBooleanOption(FadingOptions.FadeOutUnreachableCode, value); }
-        }
+        get { return GetBooleanOption(FadingOptions.FadeOutUnusedImports); }
+        set { SetBooleanOption(FadingOptions.FadeOutUnusedImports, value); }
+    }
 
-        public int Fading_FadeOutUnusedImports
-        {
-            get { return GetBooleanOption(FadingOptions.FadeOutUnusedImports); }
-            set { SetBooleanOption(FadingOptions.FadeOutUnusedImports, value); }
-        }
+    public int Fading_FadeOutUnusedMembers
+    {
+        get { return GetBooleanOption(FadingOptions.FadeOutUnusedMembers); }
+        set { SetBooleanOption(FadingOptions.FadeOutUnusedMembers, value); }
     }
 }

src/VisualStudio/CSharp/Impl/Options/AutomationObject/AutomationObject.cs

@@ -11,7 +11,7 @@
 namespace Microsoft.VisualStudio.LanguageServices.CSharp.Options
 {
     [ComVisible(true)]
-    public partial class AutomationObject : AbstractAutomationObject
+    public sealed partial class AutomationObject : AbstractAutomationObject
     {
         internal AutomationObject(ILegacyGlobalOptionService legacyGlobalOptions)
             : base(legacyGlobalOptions, LanguageNames.CSharp)

src/VisualStudio/Core/Def/ServicesVSResources.resx

@@ -763,6 +763,9 @@ Additional information: {1}</value>
   <data name="Analysis" xml:space="preserve">
     <value>Analysis</value>
   </data>
+  <data name="Fade_out_unused_members" xml:space="preserve">
+    <value>Fade out unused members</value>
+  </data>
   <data name="Fade_out_unreachable_code" xml:space="preserve">
     <value>Fade out unreachable code</value>
   </data>