Revert "fix(http-client-csharp): strip [Experimental] attribute when internalizing types" (#10972)

Reverts #10958

Author: JoshLove-msft

packages/http-client-csharp/generator/Microsoft.TypeSpec.Generator/src/PostProcessing/PostProcessor.cs

@@ -20,8 +20,6 @@ internal class PostProcessor
         private readonly HashSet<string> _typesToKeep;
         private INamedTypeSymbol? _modelFactorySymbol;
 
-        private static readonly string[] _experimentalAttributeNames = ["Experimental", "ExperimentalAttribute"];
-
         public PostProcessor(
             HashSet<string> typesToKeep,
             string? modelFactoryFullName = null,
@@ -158,12 +156,6 @@ public async Task<Project> InternalizeAsync(Project project)
                 project = MarkInternal(project, model, documentId);
             }
 
-            if (nodesToInternalize.Count > 0)
-            {
-                CodeModelGenerator.Instance.Emitter.Info(
-                    $"Internalized {nodesToInternalize.Count} unreferenced public type(s).");
-            }
-
             var modelNamesToRemove =
                 nodesToInternalize.Keys.Select(item => item.Identifier.Text);
             project = await RemoveMethodsFromModelFactoryAsync(project, definitions, modelNamesToRemove.ToHashSet());
@@ -344,13 +336,7 @@ private static IEnumerable<T> GetReferencedTypes<T>(T definition,
 
         private Project MarkInternal(Project project, BaseTypeDeclarationSyntax declarationNode, DocumentId documentId)
         {
-            CodeModelGenerator.Instance.Emitter.Debug(
-                $"Internalizing unreferenced public type '{declarationNode.Identifier.Text}'.");
-
             var newNode = ChangeModifier(declarationNode, SyntaxKind.PublicKeyword, SyntaxKind.InternalKeyword);
-            // The [Experimental] attribute is a public-API stability signal that is meaningless on a type that is
-            // being internalized, so strip it to avoid emitting it (and its use-site diagnostics) on internal types.
-            newNode = RemoveExperimentalAttribute(newNode, declarationNode.Identifier.Text);
             var tree = declarationNode.SyntaxTree;
             var document = project.GetDocument(documentId)!;
             var newRoot = tree.GetRoot().ReplaceNode(declarationNode, newNode)
@@ -359,78 +345,6 @@ private Project MarkInternal(Project project, BaseTypeDeclarationSyntax declarat
             return document.Project;
         }
 
-        /// <summary>
-        /// Removes any <c>[Experimental]</c> (<see cref="System.Diagnostics.CodeAnalysis.ExperimentalAttribute"/>)
-        /// attribute from <paramref name="declarationNode"/>. The declaration's leading trivia (such as documentation
-        /// comments and indentation) is re-attached to the resulting first token so that the surrounding formatting and
-        /// any documentation comment are preserved even when the attribute that carried them is removed.
-        /// </summary>
-        private static BaseTypeDeclarationSyntax RemoveExperimentalAttribute(
-            BaseTypeDeclarationSyntax declarationNode,
-            string typeName)
-        {
-            if (declarationNode.AttributeLists.Count == 0)
-            {
-                return declarationNode;
-            }
-
-            var newAttributeLists = new List<AttributeListSyntax>();
-            bool removed = false;
-
-            foreach (var attributeList in declarationNode.AttributeLists)
-            {
-                var keptAttributes = attributeList.Attributes
-                    .Where(attribute => !IsExperimentalAttribute(attribute))
-                    .ToList();
-
-                if (keptAttributes.Count == attributeList.Attributes.Count)
-                {
-                    // Nothing removed from this list.
-                    newAttributeLists.Add(attributeList);
-                }
-                else if (keptAttributes.Count > 0)
-                {
-                    // Keep the remaining (non-experimental) attributes in this list.
-                    removed = true;
-                    newAttributeLists.Add(attributeList.WithAttributes(SyntaxFactory.SeparatedList(keptAttributes)));
-                }
-                else
-                {
-                    // The entire list only contained experimental attributes and is dropped.
-                    removed = true;
-                }
-            }
-
-            if (!removed)
-            {
-                return declarationNode;
-            }
-
-            CodeModelGenerator.Instance.Emitter.Debug(
-                $"Removed [Experimental] attribute from '{typeName}' while internalizing it.");
-
-            // Preserve the original leading trivia (e.g. documentation comments and indentation) by re-attaching it to
-            // whatever token now leads the declaration. This keeps the doc comment even when it was attached to the
-            // attribute list that was removed.
-            var originalLeadingTrivia = declarationNode.GetLeadingTrivia();
-            var newNode = declarationNode.WithAttributeLists(SyntaxFactory.List(newAttributeLists));
-            var firstToken = newNode.GetFirstToken();
-
-            return newNode.ReplaceToken(firstToken, firstToken.WithLeadingTrivia(originalLeadingTrivia));
-        }
-
-        private static bool IsExperimentalAttribute(AttributeSyntax attribute)
-        {
-            var name = attribute.Name switch
-            {
-                QualifiedNameSyntax qualified => qualified.Right.Identifier.Text,
-                IdentifierNameSyntax identifier => identifier.Identifier.Text,
-                _ => attribute.Name.ToString()
-            };
-
-            return Array.IndexOf(_experimentalAttributeNames, name) >= 0;
-        }
-
         private async Task<Project> RemoveModelsAsync(Project project,
             IEnumerable<BaseTypeDeclarationSyntax> unusedModels)
         {

packages/http-client-csharp/generator/Microsoft.TypeSpec.Generator/test/PostProcessing/PostProcessorTests.cs

@@ -3,12 +3,10 @@
 
 using System.ClientModel.Primitives;
 using System.Collections.Generic;
-using System.Diagnostics.CodeAnalysis;
 using System.IO;
 using System.Linq;
 using System.Threading.Tasks;
 using Microsoft.CodeAnalysis;
-using Microsoft.CodeAnalysis.CSharp;
 using Microsoft.CodeAnalysis.CSharp.Syntax;
 using Microsoft.TypeSpec.Generator.Tests.Common;
 using NUnit.Framework;
@@ -291,100 +289,6 @@ public async Task DoesNotRemoveValidAttributes()
             Assert.AreEqual(Helpers.GetExpectedFromFile().TrimEnd(), output, "The output should match the expected content.");
         }
 
-        [Test]
-        public async Task RemovesExperimentalAttributeWhenInternalizing()
-        {
-            MockHelpers.LoadMockGenerator();
-            var workspace = new AdhocWorkspace();
-            var projectInfo = ProjectInfo.Create(
-                    ProjectId.CreateNewId(),
-                    VersionStamp.Create(),
-                    name: "TestProj",
-                    assemblyName: "TestProj",
-                    language: LanguageNames.CSharp)
-                .WithMetadataReferences(new[]
-                {
-                    MetadataReference.CreateFromFile(typeof(object).Assembly.Location),
-                    MetadataReference.CreateFromFile(typeof(ExperimentalAttribute).Assembly.Location)
-                });
-
-            var project = workspace.AddProject(projectInfo);
-            var folder = Helpers.GetAssetFileOrDirectoryPath(false);
-            const string rootFileName = "ExperimentalInternalizeRoot.cs";
-            string[] modelFileNames =
-            [
-                "ReferencedModel.cs",
-                "UnreferencedModel.cs",
-                "UnreferencedWithOtherAttribute.cs",
-                "UnreferencedWithCombinedAttributes.cs"
-            ];
-            foreach (var fileName in modelFileNames)
-            {
-                project = project.AddDocument(
-                    fileName,
-                    File.ReadAllText(Path.Join(folder, fileName))).Project;
-            }
-            project = project.AddDocument(
-                rootFileName,
-                File.ReadAllText(Path.Join(folder, rootFileName))).Project;
-            var postProcessor = new TestPostProcessor(rootFileName);
-
-            var resultProject = await postProcessor.InternalizeAsync(project);
-
-            var referencedModel = await GetSingleClassAsync(resultProject, "ReferencedModel.cs", "ReferencedModel");
-            var unreferencedModel = await GetSingleClassAsync(resultProject, "UnreferencedModel.cs", "UnreferencedModel");
-            var unreferencedWithOther = await GetSingleClassAsync(resultProject, "UnreferencedWithOtherAttribute.cs", "UnreferencedWithOtherAttribute");
-            var unreferencedWithCombined = await GetSingleClassAsync(resultProject, "UnreferencedWithCombinedAttributes.cs", "UnreferencedWithCombinedAttributes");
-
-            // The referenced model stays public and keeps its [Experimental] attribute.
-            Assert.IsTrue(referencedModel.Modifiers.Any(m => m.IsKind(SyntaxKind.PublicKeyword)));
-            Assert.IsTrue(HasExperimentalAttribute(referencedModel), "Referenced (public) model should keep [Experimental].");
-
-            // The unreferenced model is internalized and loses its [Experimental] attribute.
-            Assert.IsTrue(unreferencedModel.Modifiers.Any(m => m.IsKind(SyntaxKind.InternalKeyword)));
-            Assert.IsFalse(unreferencedModel.Modifiers.Any(m => m.IsKind(SyntaxKind.PublicKeyword)));
-            Assert.IsFalse(HasExperimentalAttribute(unreferencedModel), "Internalized model should not keep [Experimental].");
-
-            // The documentation comment on the internalized type is preserved.
-            Assert.IsTrue(
-                unreferencedModel.GetLeadingTrivia().ToFullString().Contains("not referenced"),
-                "Doc comment of the internalized type should be preserved.");
-
-            // An internalized type with another attribute in a separate list keeps the other attribute.
-            Assert.IsTrue(unreferencedWithOther.Modifiers.Any(m => m.IsKind(SyntaxKind.InternalKeyword)));
-            Assert.IsFalse(HasExperimentalAttribute(unreferencedWithOther), "Internalized model should not keep [Experimental].");
-            Assert.IsTrue(HasAttribute(unreferencedWithOther, "Serializable"), "Other attributes should be preserved.");
-            Assert.IsTrue(
-                unreferencedWithOther.GetLeadingTrivia().ToFullString().Contains("must be preserved"),
-                "Doc comment should be preserved when only one of several attribute lists is removed.");
-
-            // An internalized type with the experimental attribute combined in a single list keeps the others.
-            Assert.IsTrue(unreferencedWithCombined.Modifiers.Any(m => m.IsKind(SyntaxKind.InternalKeyword)));
-            Assert.IsFalse(HasExperimentalAttribute(unreferencedWithCombined), "Internalized model should not keep [Experimental].");
-            Assert.IsTrue(HasAttribute(unreferencedWithCombined, "Serializable"), "Other attributes in the same list should be preserved.");
-        }
-
-        private static async Task<ClassDeclarationSyntax> GetSingleClassAsync(Project project, string fileName, string className)
-        {
-            var doc = project.Documents.Single(d => d.Name == fileName);
-            var root = await doc.GetSyntaxRootAsync();
-            return ((CompilationUnitSyntax)root!)
-                .DescendantNodes()
-                .OfType<ClassDeclarationSyntax>()
-                .Single(t => t.Identifier.Text == className);
-        }
-
-        private static bool HasAttribute(BaseTypeDeclarationSyntax type, string attributeName)
-            => type.AttributeLists
-                .SelectMany(list => list.Attributes)
-                .Any(attr => attr.Name.ToString() == attributeName);
-
-
-        private static bool HasExperimentalAttribute(BaseTypeDeclarationSyntax type)
-            => type.AttributeLists
-                .SelectMany(list => list.Attributes)
-                .Any(attr => attr.Name.ToString() is "Experimental" or "ExperimentalAttribute");
-
         private class TestPostProcessor : PostProcessor
         {
             private readonly string _rootFile;