Add missing LSP Handlers

src/OmniSharp.Abstractions/Models/v2/CodeFoldingBlock.cs

@@ -22,8 +22,8 @@ public CodeFoldingBlock(Range textSpan, string type)
 
     public class CodeFoldingBlockKinds
     {
-        public static readonly string Comment = nameof(Comment);
-        public static readonly string Imports = nameof(Imports);
-        public static readonly string Region = nameof(Region);
+        public const string Comment = nameof(Comment);
+        public const string Imports = nameof(Imports);
+        public const string Region = nameof(Region);
     }
 }

src/OmniSharp.LanguageServerProtocol/Handlers/OmniSharpDocumentHighlightHandler.cs

@@ -0,0 +1,69 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading;
+using System.Threading.Tasks;
+using OmniSharp.Extensions.JsonRpc;
+using OmniSharp.Extensions.LanguageServer.Protocol.Client.Capabilities;
+using OmniSharp.Extensions.LanguageServer.Protocol.Document;
+using OmniSharp.Extensions.LanguageServer.Protocol.Models;
+using OmniSharp.Models;
+using OmniSharp.Models.FindUsages;
+
+namespace OmniSharp.LanguageServerProtocol.Handlers
+{
+    internal sealed class OmniSharpDocumentHighlightHandler : DocumentHighlightHandlerBase
+    {
+        public static IEnumerable<IJsonRpcHandler> Enumerate(RequestHandlers handlers)
+        {
+            foreach (var (selector, handler) in handlers
+                .OfType<Mef.IRequestHandler<FindUsagesRequest, QuickFixResponse>>())
+                if (handler != null)
+                    yield return new OmniSharpDocumentHighlightHandler(handler, selector);
+        }
+
+        private readonly Mef.IRequestHandler<FindUsagesRequest, QuickFixResponse> _findUsagesHandler;
+        private readonly DocumentSelector _documentSelector;
+
+        public OmniSharpDocumentHighlightHandler(Mef.IRequestHandler<FindUsagesRequest, QuickFixResponse> findUsagesHandler, DocumentSelector documentSelector)
+        {
+            _findUsagesHandler = findUsagesHandler;
+            _documentSelector = documentSelector;
+        }
+
+        public override async Task<DocumentHighlightContainer> Handle(DocumentHighlightParams request, CancellationToken token)
+        {
+            // TODO: Utilize Roslyn ExternalAccess to take advantage of HighlightingService.
+
+            var omnisharpRequest = new FindUsagesRequest
+            {
+                FileName = Helpers.FromUri(request.TextDocument.Uri),
+                Column = Convert.ToInt32(request.Position.Character),
+                Line = Convert.ToInt32(request.Position.Line),
+                OnlyThisFile = true,
+                ExcludeDefinition = false
+            };
+
+            var omnisharpResponse = await _findUsagesHandler.Handle(omnisharpRequest);
+
+            if (omnisharpResponse.QuickFixes is null)
+            {
+                return new DocumentHighlightContainer();
+            }
+
+            return new DocumentHighlightContainer(omnisharpResponse.QuickFixes.Select(x => new DocumentHighlight
+            {
+                Kind = DocumentHighlightKind.Read,
+                Range = x.ToRange()
+            }));
+        }
+
+        protected override DocumentHighlightRegistrationOptions CreateRegistrationOptions(DocumentHighlightCapability capability, ClientCapabilities clientCapabilities)
+        {
+            return new DocumentHighlightRegistrationOptions()
+            {
+                DocumentSelector = _documentSelector
+            };
+        }
+    }
+}

src/OmniSharp.LanguageServerProtocol/Handlers/OmniSharpDocumentOnTypeFormattingHandler.cs

@@ -56,9 +56,9 @@ protected override DocumentOnTypeFormattingRegistrationOptions CreateRegistratio
             return new DocumentOnTypeFormattingRegistrationOptions()
             {
                 DocumentSelector = _documentSelector,
-                FirstTriggerCharacter = ";",
-                // TODO: What should these be?
-                MoreTriggerCharacter = new[] {"}", ")"}
+                // Chose these triggers based on Roslyn's implementation https://github.com/dotnet/roslyn/blob/9e06c76c5ce94dc49821c5bd211c8292b3a984f0/src/Features/LanguageServer/Protocol/DefaultCapabilitiesProvider.cs#L71
+                FirstTriggerCharacter = "}",
+                MoreTriggerCharacter = new[] { ";", "\n" }
             };
         }
     }

src/OmniSharp.LanguageServerProtocol/Handlers/OmniSharpFoldingRangeHandler.cs

@@ -0,0 +1,75 @@
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading;
+using System.Threading.Tasks;
+using OmniSharp.Extensions.JsonRpc;
+using OmniSharp.Extensions.LanguageServer.Protocol.Client.Capabilities;
+using OmniSharp.Extensions.LanguageServer.Protocol.Document;
+using OmniSharp.Extensions.LanguageServer.Protocol.Models;
+using OmniSharp.Models.V2;
+using static OmniSharp.LanguageServerProtocol.Helpers;
+
+namespace OmniSharp.LanguageServerProtocol.Handlers
+{
+    class OmniSharpFoldingRangenHandler : FoldingRangeHandlerBase
+    {
+        public static IEnumerable<IJsonRpcHandler> Enumerate(RequestHandlers handlers)
+        {
+            foreach (var (selector, handler) in handlers.OfType<Mef.IRequestHandler<BlockStructureRequest, BlockStructureResponse>>())
+                if (handler != null)
+                    yield return new OmniSharpFoldingRangenHandler(handler, selector);
+        }
+
+        private readonly Mef.IRequestHandler<BlockStructureRequest, BlockStructureResponse> _definitionHandler;
+        private readonly DocumentSelector _documentSelector;
+
+        public OmniSharpFoldingRangenHandler(Mef.IRequestHandler<BlockStructureRequest, BlockStructureResponse> definitionHandler, DocumentSelector documentSelector)
+        {
+            _definitionHandler = definitionHandler;
+            _documentSelector = documentSelector;
+        }
+
+        public override async Task<Container<FoldingRange>> Handle(FoldingRangeRequestParam request, CancellationToken token)
+        {
+            var omnisharpRequest = new BlockStructureRequest()
+            {
+                FileName = FromUri(request.TextDocument.Uri)
+            };
+
+            var omnisharpResponse = await _definitionHandler.Handle(omnisharpRequest);
+
+            if (omnisharpResponse.Spans is null)
+            {
+                return new Container<FoldingRange>();
+            }
+
+            return new Container<FoldingRange>(omnisharpResponse.Spans.Select(block => new FoldingRange()
+            {
+                StartLine = block.Range.Start.Line,
+                StartCharacter = block.Range.Start.Column,
+                EndLine = block.Range.End.Line,
+                EndCharacter = block.Range.End.Column,
+                Kind = ConvertKind(block.Kind),
+            }));
+        }
+
+        private static FoldingRangeKind? ConvertKind(string kind)
+        {
+            return kind switch
+            {
+                CodeFoldingBlockKinds.Comment => FoldingRangeKind.Comment,
+                CodeFoldingBlockKinds.Imports => FoldingRangeKind.Imports,
+                CodeFoldingBlockKinds.Region => FoldingRangeKind.Region,
+                _ => null
+            };
+        }
+
+        protected override FoldingRangeRegistrationOptions CreateRegistrationOptions(FoldingRangeCapability capability, ClientCapabilities clientCapabilities)
+        {
+            return new FoldingRangeRegistrationOptions()
+            {
+                DocumentSelector = _documentSelector
+            };
+        }
+    }
+}

src/OmniSharp.LanguageServerProtocol/Handlers/OmniSharpSemanticTokensHandler.cs

@@ -0,0 +1,106 @@
+using System.Collections.Generic;
+using System.Collections.Immutable;
+using System.Linq;
+using System.Threading;
+using System.Threading.Tasks;
+using OmniSharp.Extensions.JsonRpc;
+using OmniSharp.Extensions.LanguageServer.Protocol.Client.Capabilities;
+using OmniSharp.Extensions.LanguageServer.Protocol.Document;
+using OmniSharp.Extensions.LanguageServer.Protocol.Models;
+using OmniSharp.Models.SemanticHighlight;
+using OmniSharp.Roslyn.CSharp.Services.SemanticHighlight;
+using static OmniSharp.LanguageServerProtocol.Helpers;
+
+namespace OmniSharp.LanguageServerProtocol.Handlers
+{
+    class OmniSharpSemanticTokensHandler : SemanticTokensHandlerBase
+    {
+        public static IEnumerable<IJsonRpcHandler> Enumerate(RequestHandlers handlers)
+        {
+            foreach (var (selector, handler) in handlers.OfType<Mef.IRequestHandler<SemanticHighlightRequest, SemanticHighlightResponse>>())
+                if (handler != null)
+                    yield return new OmniSharpSemanticTokensHandler(handler, selector);
+        }
+
+        private readonly Mef.IRequestHandler<SemanticHighlightRequest, SemanticHighlightResponse> _definitionHandler;
+        private readonly DocumentSelector _documentSelector;
+
+        private static readonly ImmutableDictionary<SemanticHighlightClassification, SemanticTokenType> _tokenTypes
+            = SemanticHighlightService._classificationMap
+                .OrderBy(kvp => kvp.Value)
+                .Aggregate(
+                    new Dictionary<SemanticHighlightClassification, SemanticTokenType>(),
+                    (dictionary, kvp) =>
+                    {
+                        if (!dictionary.ContainsKey(kvp.Value))
+                            dictionary.Add(kvp.Value, new SemanticTokenType(kvp.Key));
+                        return dictionary;
+                    })
+                    .ToImmutableDictionary();
+
+        private static readonly ImmutableDictionary<SemanticHighlightModifier, SemanticTokenModifier> _tokenModifiers
+            = SemanticHighlightService._modifierMap
+                .OrderBy(kvp => kvp.Value)
+                .Aggregate(
+                    new Dictionary<SemanticHighlightModifier, SemanticTokenModifier>(),
+                    (dictionary, kvp) =>
+                    {
+                        if (!dictionary.ContainsKey(kvp.Value))
+                            dictionary.Add(kvp.Value, new SemanticTokenModifier(kvp.Key));
+                        return dictionary;
+                    })
+                    .ToImmutableDictionary();
+
+        private readonly SemanticTokensLegend _legend = new()
+        {
+            TokenTypes = new Container<SemanticTokenType>(_tokenTypes.Values),
+            TokenModifiers = new Container<SemanticTokenModifier>(_tokenModifiers.Values),
+        };
+
+        public OmniSharpSemanticTokensHandler(Mef.IRequestHandler<SemanticHighlightRequest, SemanticHighlightResponse> definitionHandler, DocumentSelector documentSelector)
+        {
+            _definitionHandler = definitionHandler;
+            _documentSelector = documentSelector;
+        }
+
+        protected override async Task Tokenize(SemanticTokensBuilder builder, ITextDocumentIdentifierParams identifier, CancellationToken cancellationToken)
+        {
+            var omnisharpRequest = new SemanticHighlightRequest()
+            {
+                FileName = FromUri(identifier.TextDocument.Uri)
+            };
+
+            var omnisharpResponse = await _definitionHandler.Handle(omnisharpRequest);
+
+            if (omnisharpResponse.Spans is null)
+            {
+                return;
+            }
+
+            foreach (var span in omnisharpResponse.Spans)
+            {
+                var range = new Range(span.StartLine, span.StartColumn, span.EndLine, span.EndColumn);
+                builder.Push(range, _tokenTypes[span.Type], span.Modifiers.Select(modifier => _tokenModifiers[modifier]));
+            }
+        }
+
+        protected override Task<SemanticTokensDocument> GetSemanticTokensDocument(ITextDocumentIdentifierParams @params, CancellationToken cancellationToken)
+        {
+            return Task.FromResult(new SemanticTokensDocument(_legend));
+        }
+
+        protected override SemanticTokensRegistrationOptions CreateRegistrationOptions(SemanticTokensCapability capability, ClientCapabilities clientCapabilities)
+        {
+            return new SemanticTokensRegistrationOptions()
+            {
+                DocumentSelector = _documentSelector,
+                Full = new SemanticTokensCapabilityRequestFull
+                {
+                    Delta = false
+                },
+                Range = true,
+                Legend = _legend
+            };
+        }
+    }
+}

src/OmniSharp.LanguageServerProtocol/LanguageServerHost.cs

@@ -370,22 +370,25 @@ internal static void RegisterHandlers(ILanguageServer server, CompositionHost co
             var serializer = server.Services.GetRequiredService<ISerializer>();
             server.Register(s =>
             {
-                foreach (var handler in OmniSharpTextDocumentSyncHandler.Enumerate(handlers, workspace, documentVersions)
-                    .Concat(OmniSharpTypeDefinitionHandler.Enumerate(handlers))
-                    .Concat(OmniSharpDefinitionHandler.Enumerate(handlers))
-                    .Concat(OmniSharpHoverHandler.Enumerate(handlers))
-                    .Concat(OmniSharpCompletionHandler.Enumerate(handlers))
-                    .Concat(OmniSharpSignatureHelpHandler.Enumerate(handlers))
-                    .Concat(OmniSharpRenameHandler.Enumerate(handlers))
-                    .Concat(OmniSharpWorkspaceSymbolsHandler.Enumerate(handlers))
-                    .Concat(OmniSharpDocumentSymbolHandler.Enumerate(handlers))
-                    .Concat(OmniSharpReferencesHandler.Enumerate(handlers))
-                    .Concat(OmniSharpImplementationHandler.Enumerate(handlers))
+                foreach (var handler in OmniSharpCodeActionHandler.Enumerate(handlers, serializer, server, documentVersions)
                     .Concat(OmniSharpCodeLensHandler.Enumerate(handlers))
-                    .Concat(OmniSharpCodeActionHandler.Enumerate(handlers, serializer, server, documentVersions))
+                    .Concat(OmniSharpCompletionHandler.Enumerate(handlers))
+                    .Concat(OmniSharpDefinitionHandler.Enumerate(handlers))
                     .Concat(OmniSharpDocumentFormattingHandler.Enumerate(handlers))
                     .Concat(OmniSharpDocumentFormatRangeHandler.Enumerate(handlers))
-                    .Concat(OmniSharpDocumentOnTypeFormattingHandler.Enumerate(handlers)))
+                    .Concat(OmniSharpDocumentOnTypeFormattingHandler.Enumerate(handlers))
+                    .Concat(OmniSharpDocumentHighlightHandler.Enumerate(handlers))
+                    .Concat(OmniSharpDocumentSymbolHandler.Enumerate(handlers))
+                    .Concat(OmniSharpFoldingRangenHandler.Enumerate(handlers))
+                    .Concat(OmniSharpHoverHandler.Enumerate(handlers))
+                    .Concat(OmniSharpImplementationHandler.Enumerate(handlers))
+                    .Concat(OmniSharpReferencesHandler.Enumerate(handlers))
+                    .Concat(OmniSharpRenameHandler.Enumerate(handlers))
+                    .Concat(OmniSharpSemanticTokensHandler.Enumerate(handlers))
+                    .Concat(OmniSharpSignatureHelpHandler.Enumerate(handlers))
+                    .Concat(OmniSharpTextDocumentSyncHandler.Enumerate(handlers, workspace, documentVersions))
+                    .Concat(OmniSharpTypeDefinitionHandler.Enumerate(handlers))
+                    .Concat(OmniSharpWorkspaceSymbolsHandler.Enumerate(handlers)))
                 {
                     s.AddHandlers(handler);
                 }

src/OmniSharp.Roslyn.CSharp/Services/SemanticHighlight/SemanticHighlightService.cs

@@ -110,7 +110,7 @@ class ClassifiedResult
             public TextLineCollection Lines { get; set; }
         }
 
-        private static readonly Dictionary<string, SemanticHighlightClassification> _classificationMap =
+        public static readonly Dictionary<string, SemanticHighlightClassification> _classificationMap =
             new()
             {
                 [ClassificationTypeNames.Comment] = SemanticHighlightClassification.Comment,
@@ -182,7 +182,7 @@ class ClassifiedResult
                 [ClassificationTypeNames.RegexOtherEscape] = SemanticHighlightClassification.RegexOtherEscape,
             };
 
-        private static readonly Dictionary<string, SemanticHighlightModifier> _modifierMap =
+        public static readonly Dictionary<string, SemanticHighlightModifier> _modifierMap =
             new()
             {
                 [ClassificationTypeNames.StaticSymbol] = SemanticHighlightModifier.Static,