Remove more usages of specialized collections in favor of collection exprs

src/Analyzers/Core/Analyzers/PopulateSwitch/PopulateSwitchStatementHelpers.cs

@@ -71,7 +71,7 @@ public static ICollection<ISymbol> GetMissingEnumMembers(ISwitchOperation switch
             if (!TryGetAllEnumMembers(switchExpressionType, enumMembers) ||
                 !TryRemoveExistingEnumMembers(switchStatement, enumMembers))
             {
-                return SpecializedCollections.EmptyCollection<ISymbol>();
+                return [];
             }
         }
 

src/Compilers/Core/AnalyzerDriver/DeclarationComputer.cs

@@ -31,7 +31,7 @@ internal static DeclarationInfo GetDeclarationInfo(SemanticModel model, SyntaxNo
 
         internal static DeclarationInfo GetDeclarationInfo(SemanticModel model, SyntaxNode node, bool getSymbol, SyntaxNode executableCodeBlock, CancellationToken cancellationToken)
         {
-            return GetDeclarationInfo(model, node, getSymbol, SpecializedCollections.SingletonEnumerable(executableCodeBlock), cancellationToken);
+            return GetDeclarationInfo(model, node, getSymbol, [executableCodeBlock], cancellationToken);
         }
 
         internal static DeclarationInfo GetDeclarationInfo(SemanticModel model, SyntaxNode node, bool getSymbol, CancellationToken cancellationToken, params SyntaxNode[] executableCodeBlocks)

src/EditorFeatures/CSharp/AutomaticCompletion/AutomaticLineEnderCommandHandler.cs

@@ -98,9 +98,7 @@ protected override IList<TextChange> FormatBasedOnEndToken(ParsedDocument docume
         var endToken = root.FindToken(position);
         var span = GetFormattedTextSpan(root, endToken);
         if (span == null)
-        {
-            return SpecializedCollections.EmptyList<TextChange>();
-        }
+            return [];
 
         var formatter = document.LanguageServices.GetRequiredService<ISyntaxFormattingService>();
         return formatter.GetFormattingResult(

src/EditorFeatures/Core.Wpf/Interactive/InertClassifierProvider.InertClassifier.cs

@@ -35,7 +35,7 @@ public IList<ClassificationSpan> GetClassificationSpans(SnapshotSpan span)
                     return classifications.Where(c => c.Span.IntersectsWith(span)).ToList();
                 }
 
-                return SpecializedCollections.EmptyList<ClassificationSpan>();
+                return [];
             }
         }
     }

src/EditorFeatures/Core.Wpf/NavigateTo/NavigateToItemDisplay.cs

@@ -144,6 +144,6 @@ public IReadOnlyList<Span> GetNameMatchRuns(string searchValue)
             => _searchResult.NameMatchSpans.NullToEmpty().SelectAsArray(ts => ts.ToSpan());
 
         public IReadOnlyList<Span> GetAdditionalInformationMatchRuns(string searchValue)
-            => SpecializedCollections.EmptyReadOnlyList<Span>();
+            => [];
     }
 }

src/EditorFeatures/Core.Wpf/SignatureHelp/Presentation/SignatureHelpClassifier.cs

@@ -55,7 +55,7 @@ public IList<ClassificationSpan> GetClassificationSpans(SnapshotSpan span)
                 }
             }
 
-            return SpecializedCollections.EmptyList<ClassificationSpan>();
+            return [];
         }
     }
 }

src/EditorFeatures/Core/Editor/TextBufferAssociatedViewService.cs

@@ -97,7 +97,7 @@ private static IList<ITextView> GetTextViews(ITextBuffer textBuffer)
         {
             if (!s_map.TryGetValue(textBuffer, out var set))
             {
-                return SpecializedCollections.EmptyList<ITextView>();
+                return [];
             }
 
             return set.ToList();

src/EditorFeatures/Core/InlineRename/InlineRenameSession.cs

@@ -632,7 +632,7 @@ private void LogRenameSession(RenameLogMessage.UserActionOutcome outcome, bool p
                 outcome,
                 conflictResolutionFinishedComputing,
                 previewChanges,
-                SpecializedCollections.EmptyList<InlineRenameReplacementKind>()));
+                replacementKinds: []));
         }
     }
 

src/EditorFeatures/Core/Shared/Extensions/HostWorkspaceServicesExtensions.cs

@@ -94,9 +94,7 @@ internal static IList<T> SelectMatchingExtensionValues<T, TMetadata>(
             where TMetadata : ILanguageMetadata
         {
             if (items == null)
-            {
-                return SpecializedCollections.EmptyList<T>();
-            }
+                return [];
 
             return items.Where(lazy => LanguageMatches(lazy.Metadata.Language, contentType, workspaceServices)).
                 Select(lazy => lazy.Value).ToList();

src/EditorFeatures/Test/CodeGeneration/CodeGenerationTests.VisualBasic.cs

@@ -408,7 +408,6 @@ End Event
 End Class";
                 static ImmutableArray<IEventSymbol> GetExplicitInterfaceEvent(SemanticModel semanticModel)
                 {
-                    var parameterSymbols = SpecializedCollections.EmptyList<AttributeData>();
                     return ImmutableArray.Create<IEventSymbol>(
                         new CodeGenerationEventSymbol(
                             GetTypeSymbol(typeof(System.ComponentModel.INotifyPropertyChanged))(semanticModel),

src/EditorFeatures/Test/TextEditor/TextBufferAssociatedViewServiceTests.cs

@@ -31,7 +31,7 @@ public void SanityCheck()
             var bufferMock = new Mock<ITextBuffer>(MockBehavior.Strict);
             bufferMock.Setup(b => b.ContentType).Returns(contentType.Object);
 
-            var bufferCollection = new Collection<ITextBuffer>(SpecializedCollections.SingletonEnumerable(bufferMock.Object).ToList());
+            var bufferCollection = new Collection<ITextBuffer>([bufferMock.Object]);
             var dummyReason = ConnectionReason.BufferGraphChange;
 
             var exportProvider = EditorTestCompositions.EditorFeatures.ExportProviderFactory.CreateExportProvider();

src/Features/CSharp/Portable/Debugging/BreakpointResolver.cs

@@ -92,7 +92,7 @@ protected override void ParseText(
         }
         else
         {
-            nameParts = SpecializedCollections.EmptyList<NameAndArity>();
+            nameParts = [];
         }
     }
 }

src/Features/CSharp/Portable/EditAndContinue/BreakpointSpans.cs

@@ -478,7 +478,7 @@ internal static TextSpan CreateSpanForExplicitConstructorInitializer(Constructor
         => CreateSpan(constructorInitializer.ThisOrBaseKeyword, constructorInitializer.ArgumentList.CloseParenToken);
 
     internal static IEnumerable<SyntaxToken> GetActiveTokensForExplicitConstructorInitializer(ConstructorInitializerSyntax constructorInitializer)
-        => SpecializedCollections.SingletonEnumerable(constructorInitializer.ThisOrBaseKeyword).Concat(constructorInitializer.ArgumentList.DescendantTokens());
+        => [constructorInitializer.ThisOrBaseKeyword, .. constructorInitializer.ArgumentList.DescendantTokens()];
 
     internal static TextSpan CreateSpanForImplicitPrimaryConstructorInitializer(TypeDeclarationSyntax typeDeclaration)
     {

src/Features/CSharp/Portable/EncapsulateField/CSharpEncapsulateFieldService.cs

@@ -75,11 +75,8 @@ protected override async Task<SyntaxNode> RewriteFieldNameAndAccessibilityAsync(
 
             if (makePrivate)
             {
-                var modifiers = SpecializedCollections.SingletonEnumerable(Token(SyntaxKind.PrivateKeyword))
-                                                        .Concat(fieldSyntax.Modifiers.Where(m => !modifierKinds.Contains(m.Kind())));
-
                 root = root.ReplaceNode(fieldSyntax, fieldSyntax
-                    .WithModifiers([.. modifiers])
+                    .WithModifiers([Token(SyntaxKind.PrivateKeyword), .. fieldSyntax.Modifiers.Where(m => !modifierKinds.Contains(m.Kind()))])
                     .WithAdditionalAnnotations(Formatter.Annotation)
                     .WithLeadingTrivia(fieldSyntax.GetLeadingTrivia())
                     .WithTrailingTrivia(fieldSyntax.GetTrailingTrivia()));

src/Features/CSharp/Portable/SignatureHelp/AbstractCSharpSignatureHelpProvider.cs

@@ -77,5 +77,5 @@ protected static SignatureHelpSymbolParameter Convert(
 #pragma warning disable CA1822 // Mark members as static - see obsolete message above.
     protected IList<TaggedText> GetAwaitableUsage(IMethodSymbol method, SemanticModel semanticModel, int position)
 #pragma warning restore CA1822 // Mark members as static
-        => SpecializedCollections.EmptyList<TaggedText>();
+        => [];
 }

src/Features/CSharp/Portable/UsePatternMatching/CSharpIsAndCastCheckWithoutNameDiagnosticAnalyzer.cs

@@ -102,7 +102,7 @@ private void SyntaxNodeAction(
                 Descriptor, isExpression.GetLocation(),
                 styleOption.Notification,
                 context.Options,
-                SpecializedCollections.EmptyCollection<Location>(),
+                additionalLocations: [],
                 ImmutableDictionary<string, string?>.Empty));
     }
 

src/Features/CSharpTest/Diagnostics/Suppression/SuppressionTests.cs

@@ -455,8 +455,8 @@ void Method()
                         new CodeChangeProviderMetadata("SuppressionProvider", languages: [LanguageNames.CSharp]));
                     var fixService = new CodeFixService(
                         diagnosticService,
-                        SpecializedCollections.EmptyEnumerable<Lazy<IErrorLoggerService>>(),
-                        SpecializedCollections.EmptyEnumerable<Lazy<CodeFixProvider, CodeChangeProviderMetadata>>(),
+                        loggers: [],
+                        fixers: [],
                         [suppressionProviderFactory]);
                     var document = GetDocumentAndSelectSpan(workspace, out var span);
                     var diagnostics = await diagnosticService.GetDiagnosticsForSpanAsync(document, span, CancellationToken.None);

src/Features/Core/Portable/Debugging/AbstractBreakpointResolver.cs

@@ -130,7 +130,7 @@ private async Task<IEnumerable<ISymbol>> FindMembersAsync(
                 case 0:
                     // If there were no name parts, then we don't have any members to return.
                     // We only expect to hit this condition when the name provided does not parse.
-                    return SpecializedCollections.EmptyList<ISymbol>();
+                    return [];
 
                 case 1:
                     // They're just searching for a method name.  Have to look through every type to find

src/Features/Core/Portable/GenerateType/AbstractGenerateTypeService.Editor.cs

@@ -480,9 +480,7 @@ private async Task<ImmutableArray<CodeActionOperation>> GetGenerateIntoExistingD
         {
             string includeUsingsOrImports = null;
             if (!areFoldersValidIdentifiers)
-            {
-                folders = SpecializedCollections.EmptyList<string>();
-            }
+                folders = [];
 
             // Now actually create the symbol that we want to add to the root namespace.  The
             // symbol may either be a named type (if we're not generating into a namespace) or

src/Features/Core/Portable/Shared/Utilities/SupportedPlatformData.cs

@@ -23,9 +23,7 @@ internal sealed class SupportedPlatformData(Solution solution, List<ProjectId> i
     public IList<SymbolDisplayPart> ToDisplayParts()
     {
         if (InvalidProjects == null || InvalidProjects.Count == 0)
-        {
-            return SpecializedCollections.EmptyList<SymbolDisplayPart>();
-        }
+            return [];
 
         var builder = new List<SymbolDisplayPart>();
         builder.AddLineBreak();

src/Features/LanguageServer/Protocol/Features/Diagnostics/DocumentAnalysisExecutor.cs

@@ -82,7 +82,7 @@ public async Task<IEnumerable<DiagnosticData>> ComputeDiagnosticsAsync(Diagnosti
             if (analyzer == FileContentLoadAnalyzer.Instance)
             {
                 return loadDiagnostic != null
-                    ? SpecializedCollections.SingletonEnumerable(DiagnosticData.Create(loadDiagnostic, textDocument))
+                    ? [DiagnosticData.Create(loadDiagnostic, textDocument)]
                     : [];
             }
 

src/Features/Test/EditAndContinue/EditSessionActiveStatementsTests.cs

@@ -49,7 +49,7 @@ private static EditSession CreateEditSession(
                 mockDebuggerService,
                 mockCompilationOutputsProvider,
                 NullPdbMatchingSourceTextProvider.Instance,
-                SpecializedCollections.EmptyEnumerable<KeyValuePair<DocumentId, CommittedSolution.DocumentState>>(),
+                initialDocumentStates: [],
                 reportDiagnostics: true);
 
             if (initialState != CommittedSolution.DocumentState.None)

src/Tools/ExternalAccess/FSharp/SignatureHelp/FSharpSignatureHelpItem.cs

@@ -36,8 +36,7 @@ internal class FSharpSignatureHelpItem
 
         public Func<CancellationToken, IEnumerable<TaggedText>> DocumentationFactory { get; }
 
-        private static readonly Func<CancellationToken, IEnumerable<TaggedText>> s_emptyDocumentationFactory =
-            _ => SpecializedCollections.EmptyEnumerable<TaggedText>();
+        private static readonly Func<CancellationToken, IEnumerable<TaggedText>> s_emptyDocumentationFactory = _ => [];
 
         public FSharpSignatureHelpItem(
             bool isVariadic,

src/Tools/ExternalAccess/FSharp/SignatureHelp/FSharpSignatureHelpParameter.cs

@@ -53,8 +53,7 @@ internal class FSharpSignatureHelpParameter
         /// </summary>
         public IList<TaggedText> SelectedDisplayParts { get; }
 
-        private static readonly Func<CancellationToken, IEnumerable<TaggedText>> s_emptyDocumentationFactory =
-            _ => SpecializedCollections.EmptyEnumerable<TaggedText>();
+        private static readonly Func<CancellationToken, IEnumerable<TaggedText>> s_emptyDocumentationFactory = _ => [];
 
         public FSharpSignatureHelpParameter(
             string name,

src/VisualStudio/CSharp/Impl/CodeModel/CSharpCodeModelService.cs

@@ -275,17 +275,15 @@ public override bool MatchesScope(SyntaxNode node, EnvDTE.vsCMElement scope)
         }
 
         public override IEnumerable<SyntaxNode> GetOptionNodes(SyntaxNode parent)
-        {
             // Only VB has Option statements
-            return SpecializedCollections.EmptyEnumerable<SyntaxNode>();
-        }
+            => [];
 
         public override IEnumerable<SyntaxNode> GetImportNodes(SyntaxNode parent)
             => parent switch
             {
                 CompilationUnitSyntax compilationUnit => compilationUnit.Usings,
                 BaseNamespaceDeclarationSyntax baseNamespace => baseNamespace.Usings,
-                _ => SpecializedCollections.EmptyEnumerable<SyntaxNode>(),
+                _ => [],
             };
 
         private static IEnumerable<SyntaxNode> GetAttributeNodes(SyntaxList<AttributeListSyntax> attributeDeclarationList)
@@ -343,34 +341,32 @@ public override IEnumerable<SyntaxNode> GetAttributeNodes(SyntaxNode parent)
                 return GetAttributeNodes(accessor.AttributeLists);
             }
 
-            return SpecializedCollections.EmptyEnumerable<SyntaxNode>();
+            return [];
         }
 
         public override IEnumerable<SyntaxNode> GetAttributeArgumentNodes(SyntaxNode parent)
         {
             if (parent is AttributeSyntax attribute)
             {
                 if (attribute.ArgumentList == null)
-                {
-                    return SpecializedCollections.EmptyEnumerable<SyntaxNode>();
-                }
+                    return [];
 
                 return attribute.ArgumentList.Arguments;
             }
 
-            return SpecializedCollections.EmptyEnumerable<SyntaxNode>();
+            return [];
         }
 
         public override IEnumerable<SyntaxNode> GetInheritsNodes(SyntaxNode parent)
         {
             // Only VB has Inherits statements
-            return SpecializedCollections.EmptyEnumerable<SyntaxNode>();
+            return [];
         }
 
         public override IEnumerable<SyntaxNode> GetImplementsNodes(SyntaxNode parent)
         {
             // Only VB has Implements statements
-            return SpecializedCollections.EmptyEnumerable<SyntaxNode>();
+            return [];
         }
 
         private static bool IsContainerNode(SyntaxNode container)
@@ -1465,7 +1461,7 @@ public override IEnumerable<SyntaxNode> GetParameterNodes(SyntaxNode parentNode)
                 return delegateDecl.ParameterList.Parameters;
             }
 
-            return SpecializedCollections.EmptyEnumerable<ParameterSyntax>();
+            return [];
         }
 
         public override bool IsExpressionBodiedProperty(SyntaxNode node)

src/VisualStudio/Core/Def/GenerateType/GenerateTypeDialogViewModel.cs

@@ -781,7 +781,7 @@ internal GenerateTypeDialogViewModel(
         }
         else
         {
-            this.ProjectFolders = SpecializedCollections.EmptyList<string>();
+            this.ProjectFolders = [];
         }
     }
 

src/VisualStudio/Core/Def/NavigationBar/NavigationBarClient.cs

@@ -52,8 +52,8 @@ public NavigationBarClient(
 
         _workspace = workspace;
         _imageService = (IVsImageService2)serviceProvider.GetService(typeof(SVsImageService));
-        _projectItems = SpecializedCollections.EmptyList<NavigationBarProjectItem>();
-        _currentTypeItems = SpecializedCollections.EmptyList<NavigationBarItem>();
+        _projectItems = [];
+        _currentTypeItems = [];
     }
 
     private NavigationBarItem? GetCurrentTypeItem()

src/VisualStudio/Core/Def/Venus/ContainedLanguage.IVsContainedCode.cs

@@ -52,9 +52,7 @@ private IList<TextSpanAndCookie> EnumOriginalCodeBlocksWorker(CancellationToken
         var snapshot = this.SubjectBuffer.CurrentSnapshot;
         var document = snapshot.GetOpenDocumentInCurrentContextWithChanges();
         if (document == null)
-        {
-            return SpecializedCollections.EmptyList<TextSpanAndCookie>();
-        }
+            return [];
 
         return document.GetVisibleCodeBlocks(cancellationToken)
             .Select(tuple => new TextSpanAndCookie

src/VisualStudio/Core/Def/Watson/FaultReporter.cs

@@ -269,7 +269,7 @@ private static IList<string> CollectLogHubFilePaths()
             // ignore failures
         }
 
-        return SpecializedCollections.EmptyList<string>();
+        return [];
     }
 
     private static IList<string> CollectServiceHubLogFilePaths()
@@ -291,7 +291,7 @@ private static IList<string> CollectServiceHubLogFilePaths()
             // ignore failures
         }
 
-        return SpecializedCollections.EmptyList<string>();
+        return [];
     }
 
     private static List<string> CollectFilePaths(string logDirectoryPath, string logFileExtension, Func<string, bool> shouldExcludeLogFile)