Create a new GoToTypeDefinition endpoint

src/OmniSharp.Abstractions/Models/v2/GotoTypeDefinition/GotoTypeDefinitionRequest.cs

@@ -0,0 +1,11 @@
+using OmniSharp.Mef;
+
+namespace OmniSharp.Models.GotoTypeDefinition
+{
+    [OmniSharpEndpoint(OmniSharpEndpoints.GotoTypeDefinition, typeof(GotoTypeDefinitionRequest), typeof(GotoTypeDefinitionResponse))]
+    public class GotoTypeDefinitionRequest : Request
+    {
+        public int Timeout { get; init; } = 10000;
+        public bool WantMetadata { get; init; }
+    }
+}

src/OmniSharp.Abstractions/Models/v2/GotoTypeDefinition/GotoTypeDefinitionResponse.cs

@@ -0,0 +1,20 @@
+#nullable enable
+
+using OmniSharp.Models.Metadata;
+using OmniSharp.Models.v1.SourceGeneratedFile;
+using System.Collections.Generic;
+
+namespace OmniSharp.Models.GotoTypeDefinition
+{
+    public record GotoTypeDefinitionResponse
+    {
+        public List<TypeDefinition>? Definitions { get; init; }
+    }
+
+    public record TypeDefinition
+    {
+        public V2.Location Location { get; init; } = null!;
+        public MetadataSource? MetadataSource { get; init; }
+        public SourceGeneratedFileInfo? SourceGeneratedFileInfo { get; init; }
+    }
+}

src/OmniSharp.Abstractions/OmniSharpEndpoints.cs

@@ -3,6 +3,7 @@ namespace OmniSharp
     public static class OmniSharpEndpoints
     {
         public const string GotoDefinition = "/gotodefinition";
+        public const string GotoTypeDefinition = "/gototypedefinition";
         public const string FindSymbols = "/findsymbols";
         public const string UpdateBuffer = "/updatebuffer";
         public const string ChangeBuffer = "/changebuffer";

src/OmniSharp.Cake/OmniSharp.Cake.csproj

@@ -7,6 +7,7 @@
 
   <ItemGroup>
     <ProjectReference Include="..\OmniSharp.Abstractions\OmniSharp.Abstractions.csproj" />
+    <ProjectReference Include="..\OmniSharp.Roslyn.CSharp\OmniSharp.Roslyn.CSharp.csproj" />
     <ProjectReference Include="..\OmniSharp.Roslyn\OmniSharp.Roslyn.csproj" />
     <ProjectReference Include="..\OmniSharp.Shared\OmniSharp.Shared.csproj" />
   </ItemGroup>

src/OmniSharp.Cake/Services/RequestHandlers/Navigation/GotoTypeDefinitionHandler.cs

@@ -0,0 +1,119 @@
+using System;
+using System.Collections.Generic;
+using System.Composition;
+using System.Linq;
+using System.Threading.Tasks;
+using OmniSharp.Extensions;
+using OmniSharp.Mef;
+using OmniSharp.Models.GotoTypeDefinition;
+using OmniSharp.Models.Metadata;
+using OmniSharp.Models.v1.SourceGeneratedFile;
+using OmniSharp.Models.V2;
+using OmniSharp.Roslyn;
+using OmniSharp.Utilities;
+using Location = OmniSharp.Models.V2.Location;
+using Range = OmniSharp.Models.V2.Range;
+using OmniSharp.Roslyn.CSharp.Services;
+using OmniSharp.Options;
+
+namespace OmniSharp.Cake.Services.RequestHandlers.Navigation
+{
+    [OmniSharpHandler(OmniSharpEndpoints.GotoTypeDefinition, Constants.LanguageNames.Cake), Shared]
+    public class GotoTypeDefinitionHandler : CakeRequestHandler<GotoTypeDefinitionRequest, GotoTypeDefinitionResponse>
+    {
+        private readonly IExternalSourceService _externalSourceService;
+
+        [ImportingConstructor]
+        public GotoTypeDefinitionHandler(
+            OmniSharpWorkspace workspace,
+            ExternalSourceServiceFactory externalSourceServiceFactory,
+            OmniSharpOptions omniSharpOptions)
+            : base(workspace)
+        {
+            _externalSourceService = externalSourceServiceFactory?.Create(omniSharpOptions) ?? throw new ArgumentNullException(nameof(externalSourceServiceFactory));
+        }
+
+        protected override async Task<GotoTypeDefinitionResponse> TranslateResponse(GotoTypeDefinitionResponse response, GotoTypeDefinitionRequest request)
+        {
+            var definitions = new List<TypeDefinition>();
+            foreach (var definition in response.Definitions ?? Enumerable.Empty<TypeDefinition>())
+            {
+                var file = definition.Location.FileName;
+
+                if (string.IsNullOrEmpty(file) || !file.Equals(Constants.Paths.Generated))
+                {
+                    if (PlatformHelper.IsWindows && !string.IsNullOrEmpty(file))
+                    {
+                        file = file.Replace('/', '\\');
+                    }
+
+                    definitions.Add(new TypeDefinition
+                    {
+                        MetadataSource = definition.MetadataSource,
+                        SourceGeneratedFileInfo = definition.SourceGeneratedFileInfo,
+                        Location = new Location
+                        {
+                            FileName = file,
+                            Range = definition.Location.Range
+                        }
+                    });
+
+                    continue;
+                }
+
+                if (!request.WantMetadata)
+                {
+                    continue;
+                }
+
+                var aliasLocations = await GotoTypeDefinitionHandlerHelper.GetAliasFromExternalSourceAsync(
+                    Workspace,
+                    request.FileName,
+                    definition.Location.Range.End.Line,
+                    request.Timeout,
+                    _externalSourceService
+                );
+
+                definitions.AddRange(
+                    aliasLocations.Select(loc =>
+                        new TypeDefinition
+                        {
+                            Location = new Location
+                            {
+                                FileName = loc.MetadataDocument.FilePath ?? loc.MetadataDocument.Name,
+                                Range = new Range
+                                {
+                                    Start = new Point
+                                    {
+                                        Column = loc.LineSpan.StartLinePosition.Character,
+                                        Line = loc.LineSpan.StartLinePosition.Line
+                                    },
+                                    End = new Point
+                                    {
+                                        Column = loc.LineSpan.EndLinePosition.Character,
+                                        Line = loc.LineSpan.EndLinePosition.Line
+                                    },
+                                }
+                            },
+                            MetadataSource = new MetadataSource
+                            {
+                                AssemblyName = loc.Symbol.ContainingAssembly.Name,
+                                ProjectName = loc.Document.Project.Name,
+                                TypeName = loc.Symbol.GetSymbolName()
+                            },
+                            SourceGeneratedFileInfo = new SourceGeneratedFileInfo
+                            {
+                                DocumentGuid = loc.Document.Id.Id,
+                                ProjectGuid = loc.Document.Id.ProjectId.Id
+                            }
+                        })
+                        .ToList());
+            }
+
+            return new GotoTypeDefinitionResponse
+            {
+                Definitions = definitions
+            };
+        }
+    }
+}

src/OmniSharp.Cake/Services/RequestHandlers/Navigation/GotoTypeDefinitionHandlerHelper.cs

@@ -0,0 +1,126 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading;
+using System.Threading.Tasks;
+using Microsoft.CodeAnalysis;
+using Microsoft.CodeAnalysis.FindSymbols;
+using Microsoft.CodeAnalysis.Text;
+using OmniSharp.Roslyn;
+using OmniSharp.Roslyn.CSharp.Services;
+
+namespace OmniSharp.Cake.Services.RequestHandlers.Navigation
+{
+    public static class GotoTypeDefinitionHandlerHelper
+    {
+        private const int MethodLineOffset = 3;
+        private const int PropertyLineOffset = 7;
+
+        internal static async Task<IEnumerable<Alias>> GetAliasFromExternalSourceAsync(
+            OmniSharpWorkspace workspace,
+            string fileName,
+            int line,
+            int timeout,
+            IExternalSourceService externalSourceService)
+        {
+            var document = workspace.GetDocument(fileName);
+            var lineIndex = line + MethodLineOffset;
+            int column;
+
+            if (document == null)
+            {
+                return Enumerable.Empty<Alias>();
+            }
+
+            var semanticModel = await document.GetSemanticModelAsync();
+            var sourceText = await document.GetTextAsync();
+            var sourceLine = sourceText.Lines[lineIndex].ToString();
+            if (sourceLine.Contains("(Context"))
+            {
+                column = sourceLine.IndexOf("(Context", StringComparison.Ordinal);
+            }
+            else
+            {
+                lineIndex = line + PropertyLineOffset;
+                sourceLine = sourceText.Lines[lineIndex].ToString();
+                if (sourceLine.Contains("(Context"))
+                {
+                    column = sourceLine.IndexOf("(Context", StringComparison.Ordinal);
+                }
+                else
+                {
+                    return Enumerable.Empty<Alias>();
+                }
+            }
+
+            if (column > 0 && sourceLine[column - 1] == '>')
+            {
+                column = sourceLine.LastIndexOf("<", column, StringComparison.Ordinal);
+            }
+
+            var position = sourceText.Lines.GetPosition(new LinePosition(lineIndex, column));
+            var symbol = await SymbolFinder.FindSymbolAtPositionAsync(semanticModel, position, workspace);
+
+            if (symbol == null || symbol is INamespaceSymbol)
+            {
+                return Enumerable.Empty<Alias>();
+            }
+            if (symbol is IMethodSymbol method)
+            {
+                symbol = method.PartialImplementationPart ?? symbol;
+            }
+
+            var typeSymbol = symbol switch
+            {
+                ILocalSymbol localSymbol => localSymbol.Type,
+                IFieldSymbol fieldSymbol => fieldSymbol.Type,
+                IPropertySymbol propertySymbol => propertySymbol.Type,
+                IParameterSymbol parameterSymbol => parameterSymbol.Type,
+                _ => null
+            };
+
+            if (typeSymbol == null)
+                return Enumerable.Empty<Alias>();
+
+            var result = new List<Alias>();
+            foreach (var location in typeSymbol.Locations)
+            {
+                if (!location.IsInMetadata)
+                {
+                    continue;
+                }
+
+                var cancellationSource = new CancellationTokenSource(TimeSpan.FromMilliseconds(timeout));
+                var (metadataDocument, _) = await externalSourceService.GetAndAddExternalSymbolDocument(document.Project, typeSymbol, cancellationSource.Token);
+                if (metadataDocument == null)
+                {
+                    continue;
+                }
+
+                cancellationSource = new CancellationTokenSource(TimeSpan.FromMilliseconds(timeout));
+                var metadataLocation = await externalSourceService.GetExternalSymbolLocation(typeSymbol, metadataDocument, cancellationSource.Token);
+                var lineSpan = metadataLocation.GetMappedLineSpan();
+
+                result.Add(new Alias
+                {
+                    Document = document,
+                    MetadataDocument = metadataDocument,
+                    Symbol = typeSymbol,
+                    Location = location,
+                    LineSpan = lineSpan
+                });
+            }
+
+            return result;
+        }
+
+        internal class Alias
+        {
+            public Document Document { get; set; }
+            public ISymbol Symbol { get; set; }
+            public Location Location { get; set; }
+            public FileLinePositionSpan LineSpan { get; set; }
+            public Document MetadataDocument { get; set; }
+        }
+    }
+}

src/OmniSharp.Roslyn.CSharp/Services/Navigation/GotoTypeDefinitionHelpers.cs

@@ -0,0 +1,64 @@
+#nullable enable
+
+using Microsoft.CodeAnalysis;
+using Microsoft.CodeAnalysis.FindSymbols;
+using Microsoft.CodeAnalysis.Operations;
+using OmniSharp.Extensions;
+using OmniSharp.Models.v1.SourceGeneratedFile;
+using System.Diagnostics;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace OmniSharp.Roslyn.CSharp.Services.Navigation
+{
+    internal static class GotoTypeDefinitionHelpers
+    {
+        internal static async Task<ITypeSymbol?> GetTypeOfSymbol(Document document, int line, int column, CancellationToken cancellationToken)
+        {
+            var sourceText = await document.GetTextAsync(cancellationToken);
+            var position = sourceText.GetPositionFromLineAndOffset(line, column);
+            var symbol = await SymbolFinder.FindSymbolAtPositionAsync(document, position, cancellationToken);
+
+            return symbol switch
+            {
+                ILocalSymbol localSymbol => localSymbol.Type,
+                IFieldSymbol fieldSymbol => fieldSymbol.Type,
+                IPropertySymbol propertySymbol => propertySymbol.Type,
+                IParameterSymbol parameterSymbol => parameterSymbol.Type,
+                _ => null
+            };
+        }
+
+        internal static async Task<FileLinePositionSpan?> GetMetadataMappedSpan(
+            Document document,
+            ISymbol symbol,
+            IExternalSourceService externalSourceService,
+            CancellationToken cancellationToken)
+        {
+            var (metadataDocument, _) = await externalSourceService.GetAndAddExternalSymbolDocument(document.Project, symbol, cancellationToken);
+            if (metadataDocument != null)
+            {
+                var metadataLocation = await externalSourceService.GetExternalSymbolLocation(symbol, metadataDocument, cancellationToken);
+                return metadataLocation.GetMappedLineSpan();
+            }
+
+            return null;
+        }
+
+        internal static SourceGeneratedFileInfo? GetSourceGeneratedFileInfo(OmniSharpWorkspace workspace, Location location)
+        {
+            Debug.Assert(location.IsInSource);
+            var document = workspace.CurrentSolution.GetDocument(location.SourceTree);
+            if (document is not SourceGeneratedDocument)
+            {
+                return null;
+            }
+
+            return new SourceGeneratedFileInfo
+            {
+                ProjectGuid = document.Project.Id.Id,
+                DocumentGuid = document.Id.Id
+            };
+        }
+    }
+}