Ensure that the public GetOption API returns the public CodeStyle opt…

src/Features/Core/Portable/Diagnostics/AnalyzerConfigOptionSet.cs

@@ -24,7 +24,7 @@ public AnalyzerConfigOptionSet(AnalyzerConfigOptions analyzerConfigOptions, Opti
             _optionSet = optionSet;
         }
 
-        public override object GetOption(OptionKey optionKey)
+        private protected override object GetOptionCore(OptionKey optionKey)
         {
             // First try to find the option from the .editorconfig options parsed by the compiler.
             if (_analyzerConfigOptions.TryGetEditorConfigOption<object>(optionKey.Option, out var value))

src/Features/Core/Portable/Diagnostics/AnalyzerHelper.cs

@@ -140,7 +140,13 @@ public static async ValueTask<T> GetOptionAsync<T>(this AnalyzerOptions analyzer
 #pragma warning disable CS0612 // Type or member is obsolete
             var optionSet = await analyzerOptions.GetDocumentOptionSetAsync(syntaxTree, cancellationToken).ConfigureAwait(false);
 #pragma warning restore CS0612 // Type or member is obsolete
-            return (T)optionSet?.GetOption(new OptionKey(option, language)) ?? (T)option.DefaultValue!;
+
+            if (optionSet != null)
+            {
+                value = optionSet.GetOption<T>(new OptionKey(option, language));
+            }
+
+            return value ?? (T)option.DefaultValue!;
         }
 
         [PerformanceSensitive("https://github.com/dotnet/roslyn/issues/23582", OftenCompletesSynchronously = true)]

src/VisualStudio/Core/Impl/Options/AbstractOptionPreviewViewModel.cs

@@ -67,29 +67,14 @@ protected AbstractOptionPreviewViewModel(OptionStore optionStore, IServiceProvid
 
         public void SetOptionAndUpdatePreview<T>(T value, IOption option, string preview)
         {
-            if (option is Option<CodeStyleOption<T>>)
+            var key = new OptionKey(option, option.IsPerLanguage ? Language : null);
+            if (option.DefaultValue is ICodeStyleOption codeStyleOption)
             {
-                var opt = OptionStore.GetOption((Option<CodeStyleOption<T>>)option);
-                opt.Value = value;
-                OptionStore.SetOption((Option<CodeStyleOption<T>>)option, opt);
-            }
-            else if (option is PerLanguageOption<CodeStyleOption<T>>)
-            {
-                var opt = OptionStore.GetOption((PerLanguageOption<CodeStyleOption<T>>)option, Language);
-                opt.Value = value;
-                OptionStore.SetOption((PerLanguageOption<CodeStyleOption<T>>)option, Language, opt);
-            }
-            else if (option is Option<T>)
-            {
-                OptionStore.SetOption((Option<T>)option, value);
-            }
-            else if (option is PerLanguageOption<T>)
-            {
-                OptionStore.SetOption((PerLanguageOption<T>)option, Language, value);
+                OptionStore.SetOption(key, codeStyleOption.WithValue(value));
             }
             else
             {
-                throw new InvalidOperationException("Unexpected option type");
+                OptionStore.SetOption(key, value);
             }
 
             UpdateDocument(preview);

src/VisualStudio/Core/Impl/Options/OptionStore.cs

@@ -26,6 +26,7 @@ public OptionStore(OptionSet optionSet, IEnumerable<IOption> registeredOptions)
         }
 
         public object GetOption(OptionKey optionKey) => _optionSet.GetOption(optionKey);
+        public T GetOption<T>(OptionKey optionKey) => _optionSet.GetOption<T>(optionKey);
         public T GetOption<T>(Option<T> option) => _optionSet.GetOption(option);
         internal T GetOption<T>(Option2<T> option) => _optionSet.GetOption(option);
         public T GetOption<T>(PerLanguageOption<T> option, string language) => _optionSet.GetOption(option, language);

src/VisualStudio/Core/Test.Next/Mocks/TestOptionSet.cs

@@ -23,7 +23,7 @@ private TestOptionSet(ImmutableDictionary<OptionKey, object> values)
             _values = values;
         }
 
-        public override object GetOption(OptionKey optionKey)
+        private protected override object GetOptionCore(OptionKey optionKey)
         {
             Contract.ThrowIfFalse(_values.TryGetValue(optionKey, out var value));
 

src/Workspaces/Core/Portable/CodeStyle/CodeStyleOption.cs

@@ -33,6 +33,7 @@ public T Value
         ICodeStyleOption ICodeStyleOption.WithNotification(NotificationOption2 notification) => new CodeStyleOption<T>(Value, (NotificationOption)notification);
         ICodeStyleOption ICodeStyleOption.AsCodeStyleOption<TCodeStyleOption>()
             => this is TCodeStyleOption ? this : (ICodeStyleOption)_codeStyleOptionImpl;
+        ICodeStyleOption ICodeStyleOption.AsPublicCodeStyleOption() => this;
 
         public NotificationOption Notification
         {

src/Workspaces/Core/Portable/Options/DocumentOptionSet.cs

@@ -26,7 +26,7 @@ internal DocumentOptionSet(OptionSet backingOptionSet, string language)
             _language = language;
         }
 
-        public override object? GetOption(OptionKey optionKey)
+        private protected override object? GetOptionCore(OptionKey optionKey)
             => _backingOptionSet.GetOption(optionKey);
 
         public T GetOption<T>(PerLanguageOption<T> option)

src/Workspaces/Core/Portable/Options/OptionServiceFactory.cs

@@ -187,7 +187,7 @@ public DocumentSpecificOptionSet(List<IDocumentOptions> documentOptions, OptionS
                 }
 
                 [PerformanceSensitive("https://github.com/dotnet/roslyn/issues/30819", AllowLocks = false)]
-                public override object? GetOption(OptionKey optionKey)
+                private protected override object? GetOptionCore(OptionKey optionKey)
                 {
                     // If we already know the document specific value, we're done
                     if (_values.TryGetValue(optionKey, out var value))

src/Workspaces/Core/Portable/Options/OptionSet.cs

@@ -22,40 +22,55 @@ public abstract partial class OptionSet
         /// </summary>
         private ImmutableDictionary<string, AnalyzerConfigOptions> _lazyAnalyzerConfigOptions = s_emptyAnalyzerConfigOptions;
 
+        private protected abstract object? GetOptionCore(OptionKey optionKey);
+
         /// <summary>
         /// Gets the value of the option, or the default value if not otherwise set.
         /// </summary>
-        public abstract object? GetOption(OptionKey optionKey);
+        public object? GetOption(OptionKey optionKey)
+            => OptionsHelpers.GetPublicOption(optionKey, GetOptionCore);
+
+        /// <summary>
+        /// Gets the value of the option cast to type <typeparamref name="T"/>, or the default value if not otherwise set.
+        /// </summary>
+        public T GetOption<T>(OptionKey optionKey)
+            => OptionsHelpers.GetOption<T>(optionKey, GetOptionCore);
 
         /// <summary>
         /// Gets the value of the option, or the default value if not otherwise set.
         /// </summary>
         internal object? GetOption(OptionKey2 optionKey)
-            => OptionsHelpers.GetOption<object?>(optionKey, GetOption);
+            => OptionsHelpers.GetOption<object?>(optionKey, GetOptionCore);
+
+        /// <summary>
+        /// Gets the value of the option cast to type <typeparamref name="T"/>, or the default value if not otherwise set.
+        /// </summary>
+        internal T GetOption<T>(OptionKey2 optionKey)
+            => OptionsHelpers.GetOption<T>(optionKey, GetOptionCore);
 
         /// <summary>
         /// Gets the value of the option, or the default value if not otherwise set.
         /// </summary>
         public T GetOption<T>(Option<T> option)
-            => OptionsHelpers.GetOption(option, GetOption);
+            => OptionsHelpers.GetOption(option, GetOptionCore);
 
         /// <summary>
         /// Gets the value of the option, or the default value if not otherwise set.
         /// </summary>
         internal T GetOption<T>(Option2<T> option)
-            => OptionsHelpers.GetOption(option, GetOption);
+            => OptionsHelpers.GetOption(option, GetOptionCore);
 
         /// <summary>
         /// Gets the value of the option, or the default value if not otherwise set.
         /// </summary>
         public T GetOption<T>(PerLanguageOption<T> option, string? language)
-            => OptionsHelpers.GetOption(option, language, GetOption);
+            => OptionsHelpers.GetOption(option, language, GetOptionCore);
 
         /// <summary>
         /// Gets the value of the option, or the default value if not otherwise set.
         /// </summary>
         internal T GetOption<T>(PerLanguageOption2<T> option, string? language)
-            => OptionsHelpers.GetOption(option, language, GetOption);
+            => OptionsHelpers.GetOption(option, language, GetOptionCore);
 
         /// <summary>
         /// Creates a new <see cref="OptionSet" /> that contains the changed value.

src/Workspaces/Core/Portable/Options/OptionsHelpers.cs

@@ -36,5 +36,16 @@ public static T GetOption<T>(OptionKey optionKey, Func<OptionKey, object?> getOp
 
             return (T)value!;
         }
+
+        public static object? GetPublicOption(OptionKey optionKey, Func<OptionKey, object?> getOption)
+        {
+            var value = getOption(optionKey);
+            if (value is ICodeStyleOption codeStyleOption)
+            {
+                return codeStyleOption.AsPublicCodeStyleOption();
+            }
+
+            return value;
+        }
     }
 }

src/Workspaces/Core/Portable/Options/SerializableOptionSet.WorkspaceOptionSet.cs

@@ -37,7 +37,7 @@ private WorkspaceOptionSet(IOptionService service, ImmutableDictionary<OptionKey
             }
 
             [PerformanceSensitive("https://github.com/dotnet/roslyn/issues/30819", AllowLocks = false)]
-            public override object? GetOption(OptionKey optionKey)
+            private protected override object? GetOptionCore(OptionKey optionKey)
             {
                 if (_values.TryGetValue(optionKey, out var value))
                 {

src/Workspaces/Core/Portable/Options/SerializableOptionSet.cs

@@ -106,7 +106,7 @@ public SerializableOptionSet WithLanguages(ImmutableHashSet<string> languages)
         }
 
         [PerformanceSensitive("https://github.com/dotnet/roslyn/issues/30819", AllowLocks = false)]
-        public override object? GetOption(OptionKey optionKey)
+        private protected override object? GetOptionCore(OptionKey optionKey)
         {
             if (_serializableOptionValues.TryGetValue(optionKey, out var value))
             {

src/Workspaces/Core/Portable/PublicAPI.Unshipped.txt

@@ -3,6 +3,10 @@ Microsoft.CodeAnalysis.Editing.DeclarationModifiers.IsVolatile.get -> bool
 Microsoft.CodeAnalysis.Editing.DeclarationModifiers.WithIsExtern(bool isExtern) -> Microsoft.CodeAnalysis.Editing.DeclarationModifiers
 Microsoft.CodeAnalysis.Editing.DeclarationModifiers.WithIsVolatile(bool isVolatile) -> Microsoft.CodeAnalysis.Editing.DeclarationModifiers
 Microsoft.CodeAnalysis.Editing.SyntaxGenerator.ElementBindingExpression(params Microsoft.CodeAnalysis.SyntaxNode[] arguments) -> Microsoft.CodeAnalysis.SyntaxNode
+Microsoft.CodeAnalysis.Options.OptionSet.GetOption(Microsoft.CodeAnalysis.Options.OptionKey optionKey) -> object
+*REMOVED*override Microsoft.CodeAnalysis.Options.DocumentOptionSet.GetOption(Microsoft.CodeAnalysis.Options.OptionKey optionKey) -> object
+*REMOVED*abstract Microsoft.CodeAnalysis.Options.OptionSet.GetOption(Microsoft.CodeAnalysis.Options.OptionKey optionKey) -> object
+Microsoft.CodeAnalysis.Options.OptionSet.GetOption<T>(Microsoft.CodeAnalysis.Options.OptionKey optionKey) -> T
 Microsoft.CodeAnalysis.Project.RemoveDocuments(System.Collections.Immutable.ImmutableArray<Microsoft.CodeAnalysis.DocumentId> documentIds) -> Microsoft.CodeAnalysis.Project
 Microsoft.CodeAnalysis.Solution.RemoveAdditionalDocuments(System.Collections.Immutable.ImmutableArray<Microsoft.CodeAnalysis.DocumentId> documentIds) -> Microsoft.CodeAnalysis.Solution
 Microsoft.CodeAnalysis.Solution.RemoveAnalyzerConfigDocuments(System.Collections.Immutable.ImmutableArray<Microsoft.CodeAnalysis.DocumentId> documentIds) -> Microsoft.CodeAnalysis.Solution

src/Workspaces/CoreTest/WorkspaceServiceTests/OptionServiceTests.cs

@@ -316,25 +316,44 @@ private static void TestCodeStyleOptionsCommon<TCodeStyleOption>(IOption2 option
             var optionKey = new OptionKey(option, language);
             var optionKey2 = new OptionKey2(option, language);
 
-            //  1. WithChangedOption(OptionKey), GetOption(OptionKey)
-            var newOptionSet = originalOptionSet.WithChangedOption(optionKey, newValue);
-            Assert.Equal(newValue, newOptionSet.GetOption(optionKey));
+            // Value return from "object GetOption(OptionKey)" should always be public CodeStyleOption type.
+            var newPublicValue = newValue.AsPublicCodeStyleOption();
 
-            //  2. WithChangedOption(OptionKey), GetOption(OptionKey2)
+            //  1. WithChangedOption(OptionKey), GetOption(OptionKey)/GetOption<T>(OptionKey)
+            var newOptionSet = originalOptionSet.WithChangedOption(optionKey, newValue);
+            Assert.Equal(newPublicValue, newOptionSet.GetOption(optionKey));
+            // Value returned from public API should always be castable to public CodeStyleOption type.
+            Assert.NotNull((CodeStyleOption<bool>)newOptionSet.GetOption(optionKey)!);
+            // Verify "T GetOption<T>(OptionKey)" works for both cases of T being a public and internal code style option type.
+            Assert.Equal(newPublicValue, newOptionSet.GetOption<CodeStyleOption<bool>>(optionKey));
+            Assert.Equal(newValue, newOptionSet.GetOption<TCodeStyleOption>(optionKey));
+
+            //  2. WithChangedOption(OptionKey), GetOption(OptionKey2)/GetOption<T>(OptionKey2)
             newOptionSet = originalOptionSet.WithChangedOption(optionKey, newValue);
-            Assert.Equal(newValue, newOptionSet.GetOption(optionKey2));
+            Assert.Equal(newPublicValue, newOptionSet.GetOption(optionKey2));
+            // Verify "T GetOption<T>(OptionKey2)" works for both cases of T being a public and internal code style option type.
+            Assert.Equal(newPublicValue, newOptionSet.GetOption<CodeStyleOption<bool>>(optionKey2));
+            Assert.Equal(newValue, newOptionSet.GetOption<TCodeStyleOption>(optionKey2));
 
-            //  3. WithChangedOption(OptionKey2), GetOption(OptionKey)
+            //  3. WithChangedOption(OptionKey2), GetOption(OptionKey)/GetOption<T>(OptionKey)
             newOptionSet = originalOptionSet.WithChangedOption(optionKey2, newValue);
-            Assert.Equal(newValue, newOptionSet.GetOption(optionKey));
-
-            //  4. WithChangedOption(OptionKey2), GetOption(OptionKey2)
+            Assert.Equal(newPublicValue, newOptionSet.GetOption(optionKey));
+            // Value returned from public API should always be castable to public CodeStyleOption type.
+            Assert.NotNull((CodeStyleOption<bool>)newOptionSet.GetOption(optionKey)!);
+            // Verify "T GetOption<T>(OptionKey)" works for both cases of T being a public and internal code style option type.
+            Assert.Equal(newPublicValue, newOptionSet.GetOption<CodeStyleOption<bool>>(optionKey));
+            Assert.Equal(newValue, newOptionSet.GetOption<TCodeStyleOption>(optionKey));
+
+            //  4. WithChangedOption(OptionKey2), GetOption(OptionKey2)/GetOption<T>(OptionKey2)
             newOptionSet = originalOptionSet.WithChangedOption(optionKey2, newValue);
-            Assert.Equal(newValue, newOptionSet.GetOption(optionKey2));
+            Assert.Equal(newPublicValue, newOptionSet.GetOption(optionKey2));
+            // Verify "T GetOption<T>(OptionKey2)" works for both cases of T being a public and internal code style option type.
+            Assert.Equal(newPublicValue, newOptionSet.GetOption<CodeStyleOption<bool>>(optionKey2));
+            Assert.Equal(newValue, newOptionSet.GetOption<TCodeStyleOption>(optionKey2));
 
             //  5. IOptionService.GetOption(OptionKey)
             optionService.SetOptions(newOptionSet);
-            Assert.Equal(newValue, optionService.GetOption(optionKey));
+            Assert.Equal(newPublicValue, optionService.GetOption(optionKey));
         }
     }
 }

src/Workspaces/SharedUtilitiesAndExtensions/Compiler/Core/CodeStyle/CodeStyleOption2`1.cs

@@ -17,6 +17,9 @@ internal interface ICodeStyleOption
         ICodeStyleOption WithValue(object value);
         ICodeStyleOption WithNotification(NotificationOption2 notification);
         ICodeStyleOption AsCodeStyleOption<TCodeStyleOption>();
+#if !CODE_STYLE
+        ICodeStyleOption AsPublicCodeStyleOption();
+#endif
     }
 
     /// <summary>
@@ -58,6 +61,8 @@ ICodeStyleOption ICodeStyleOption.AsCodeStyleOption<TCodeStyleOption>()
             => this;
 #else
             => this is TCodeStyleOption ? this : (ICodeStyleOption)new CodeStyleOption<T>(this);
+
+        ICodeStyleOption ICodeStyleOption.AsPublicCodeStyleOption() => new CodeStyleOption<T>(this);
 #endif
 
         private int EnumValueAsInt32 => (int)(object)Value;

src/Workspaces/SharedUtilitiesAndExtensions/Compiler/Core/Options/EditorConfig/EditorConfigStorageLocation`1.cs

@@ -9,6 +9,7 @@
 using System.Diagnostics;
 using System.Diagnostics.CodeAnalysis;
 using System.Linq;
+using Microsoft.CodeAnalysis.CodeStyle;
 using Roslyn.Utilities;
 
 #if CODE_STYLE
@@ -104,6 +105,18 @@ string IEditorConfigStorageLocation2.GetEditorConfigString(object? value, Option
             => $"{KeyName} = {((IEditorConfigStorageLocation2)this).GetEditorConfigStringValue(value, optionSet)}";
 
         string IEditorConfigStorageLocation2.GetEditorConfigStringValue(object? value, OptionSet optionSet)
-            => GetEditorConfigStringValue((T)value!, optionSet);
+        {
+            T typedValue;
+            if (value is ICodeStyleOption codeStyleOption)
+            {
+                typedValue = (T)codeStyleOption.AsCodeStyleOption<T>();
+            }
+            else
+            {
+                typedValue = (T)value;
+            }
+
+            return GetEditorConfigStringValue(typedValue!, optionSet);
+        }
     }
 }