Add support for GoToDefinition on source-generated files

src/OmniSharp.Abstractions/Models/v1/GotoDefinition/GotoDefinitionResponse.cs

@@ -1,16 +1,20 @@
+#nullable enable
+
 using Newtonsoft.Json;
 using OmniSharp.Models.Metadata;
+using OmniSharp.Models.v1.SourceGeneratedFile;
 
 namespace OmniSharp.Models.GotoDefinition
 {
     public class GotoDefinitionResponse : ICanBeEmptyResponse
     {
-        public string FileName { get; set; }
+        public string? FileName { get; set; }
         [JsonConverter(typeof(ZeroBasedIndexConverter))]
         public int Line { get; set; }
         [JsonConverter(typeof(ZeroBasedIndexConverter))]
         public int Column { get; set; }
-        public MetadataSource MetadataSource { get; set; }
-        public bool IsEmpty => string.IsNullOrWhiteSpace(FileName) && MetadataSource == null;
+        public MetadataSource? MetadataSource { get; set; }
+        public SourceGeneratedFileInfo? SourceGeneratedInfo { get; set; }
+        public bool IsEmpty => string.IsNullOrWhiteSpace(FileName) && MetadataSource == null && SourceGeneratedInfo == null;
     }
 }

src/OmniSharp.Abstractions/Models/v1/SourceGeneratedFile/SourceGeneratedFileClosedRequest.cs

@@ -0,0 +1,11 @@
+#nullable enable
+
+using OmniSharp.Mef;
+
+namespace OmniSharp.Models.v1.SourceGeneratedFile
+{
+    [OmniSharpEndpoint(OmniSharpEndpoints.SourceGeneratedFileClosed, typeof(SourceGeneratedFileClosedRequest), typeof(SourceGeneratedFileClosedResponse))]
+    public sealed record SourceGeneratedFileClosedRequest : SourceGeneratedFileInfo, IRequest
+    {
+    }
+}

src/OmniSharp.Abstractions/Models/v1/SourceGeneratedFile/SourceGeneratedFileClosedResponse.cs

@@ -0,0 +1,10 @@
+#nullable enable
+using System.Threading.Tasks;
+
+namespace OmniSharp.Models.v1.SourceGeneratedFile
+{
+    public sealed class SourceGeneratedFileClosedResponse
+    {
+        public static readonly Task<SourceGeneratedFileClosedResponse> Instance = Task.FromResult(new SourceGeneratedFileClosedResponse());
+    }
+}

src/OmniSharp.Abstractions/Models/v1/SourceGeneratedFile/SourceGeneratedFileInfo.cs

@@ -0,0 +1,12 @@
+#nullable enable
+
+using System;
+
+namespace OmniSharp.Models.v1.SourceGeneratedFile
+{
+    public record SourceGeneratedFileInfo
+    {
+        public Guid ProjectGuid { get; init; }
+        public Guid DocumentGuid { get; init; }
+    }
+}

src/OmniSharp.Abstractions/Models/v1/SourceGeneratedFile/SourceGeneratedFileRequest.cs

@@ -0,0 +1,12 @@
+#nullable enable
+
+using OmniSharp.Mef;
+using System;
+
+namespace OmniSharp.Models.v1.SourceGeneratedFile
+{
+    [OmniSharpEndpoint(OmniSharpEndpoints.SourceGeneratedFile, typeof(SourceGeneratedFileRequest), typeof(SourceGeneratedFileResponse))]
+    public sealed record SourceGeneratedFileRequest : SourceGeneratedFileInfo, IRequest
+    {
+    }
+}

src/OmniSharp.Abstractions/Models/v1/SourceGeneratedFile/SourceGeneratedFileResponse.cs

@@ -0,0 +1,10 @@
+#nullable enable
+
+namespace OmniSharp.Models.v1.SourceGeneratedFile
+{
+    public sealed record SourceGeneratedFileResponse
+    {
+        public string? SourceName { get; init; }
+        public string? Source { get; init; }
+    }
+}

src/OmniSharp.Abstractions/Models/v1/SourceGeneratedFile/UpdateSourceGeneratedFileRequest.cs

@@ -0,0 +1,10 @@
+#nullable enable
+using OmniSharp.Mef;
+
+namespace OmniSharp.Models.v1.SourceGeneratedFile
+{
+    [OmniSharpEndpoint(OmniSharpEndpoints.UpdateSourceGeneratedFile, typeof(UpdateSourceGeneratedFileRequest), typeof(UpdateSourceGeneratedFileResponse))]
+    public sealed record UpdateSourceGeneratedFileRequest : SourceGeneratedFileInfo, IRequest
+    {
+    }
+}

src/OmniSharp.Abstractions/Models/v1/SourceGeneratedFile/UpdateSourceGeneratedFileResponse.cs

@@ -0,0 +1,17 @@
+#nullable enable
+
+namespace OmniSharp.Models.v1.SourceGeneratedFile
+{
+    public record UpdateSourceGeneratedFileResponse
+    {
+        public UpdateType UpdateType { get; init; }
+        public string? Source { get; init; }
+    }
+
+    public enum UpdateType
+    {
+        Unchanged,
+        Deleted,
+        Modified
+    }
+}

src/OmniSharp.Abstractions/Models/v2/GotoDefinition/GotoDefinitionResponse.cs

@@ -1,6 +1,7 @@
 #nullable enable
 
 using OmniSharp.Models.Metadata;
+using OmniSharp.Models.v1.SourceGeneratedFile;
 using System.Collections.Generic;
 
 namespace OmniSharp.Models.V2.GotoDefinition
@@ -14,5 +15,6 @@ public record Definition
     {
         public Location Location { get; init; } = null!;
         public MetadataSource? MetadataSource { get; init; }
+        public SourceGeneratedFileInfo? SourceGeneratedFileInfo { get; init; }
     }
 }

src/OmniSharp.Abstractions/OmniSharpEndpoints.cs

@@ -51,6 +51,10 @@ public static class OmniSharpEndpoints
         public const string CompletionResolve = "/completion/resolve";
         public const string CompletionAfterInsert = "/completion/afterinsert";
 
+        public const string SourceGeneratedFile = "/sourcegeneratedfile";
+        public const string UpdateSourceGeneratedFile = "/updatesourcegeneratedfile";
+        public const string SourceGeneratedFileClosed = "/sourcegeneratedfileclosed";
+
         public static class V2
         {
             public const string GetCodeActions = "/v2/getcodeactions";

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

@@ -3,6 +3,8 @@
 using Microsoft.CodeAnalysis;
 using Microsoft.CodeAnalysis.FindSymbols;
 using OmniSharp.Extensions;
+using OmniSharp.Models.v1.SourceGeneratedFile;
+using System.Diagnostics;
 using System.Threading;
 using System.Threading.Tasks;
 
@@ -42,5 +44,21 @@ internal static class GoToDefinitionHelpers
 
             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
+            };
+        }
     }
 }

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

@@ -50,7 +50,8 @@ public async Task<GotoDefinitionResponse> Handle(GotoDefinitionRequest request)
                 {
                     FileName = lineSpan.Path,
                     Line = lineSpan.StartLinePosition.Line,
-                    Column = lineSpan.StartLinePosition.Character
+                    Column = lineSpan.StartLinePosition.Character,
+                    SourceGeneratedInfo = GoToDefinitionHelpers.GetSourceGeneratedFileInfo(_workspace, location)
                 };
             }
             else if (location.IsInMetadata && request.WantMetadata)

src/OmniSharp.Roslyn.CSharp/Services/Navigation/GotoDefinitionServiceV2.cs

@@ -49,7 +49,11 @@ public async Task<GotoDefinitionResponse> Handle(GotoDefinitionRequest request)
                 return new GotoDefinitionResponse()
                 {
                     Definitions = symbol.Locations
-                        .Select(location => new Definition { Location = location.GetMappedLineSpan().GetLocationFromFileLinePositionSpan() })
+                        .Select(location => new Definition
+                        {
+                            Location = location.GetMappedLineSpan().GetLocationFromFileLinePositionSpan(),
+                            SourceGeneratedFileInfo = GoToDefinitionHelpers.GetSourceGeneratedFileInfo(_workspace, location)
+                        })
                         .ToList()
                 };
             }

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

@@ -0,0 +1,105 @@
+#nullable enable
+
+using Microsoft.CodeAnalysis;
+using Microsoft.Extensions.Logging;
+using OmniSharp.Mef;
+using OmniSharp.Models.v1.SourceGeneratedFile;
+using System.Collections.Generic;
+using System.Composition;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace OmniSharp.Roslyn.CSharp.Services.Navigation
+{
+    [Shared]
+    [OmniSharpHandler(OmniSharpEndpoints.SourceGeneratedFile, LanguageNames.CSharp)]
+    [OmniSharpHandler(OmniSharpEndpoints.UpdateSourceGeneratedFile, LanguageNames.CSharp)]
+    [OmniSharpHandler(OmniSharpEndpoints.SourceGeneratedFileClosed, LanguageNames.CSharp)]
+    public class SourceGeneratedFileService :
+        IRequestHandler<SourceGeneratedFileRequest, SourceGeneratedFileResponse>,
+        IRequestHandler<UpdateSourceGeneratedFileRequest, UpdateSourceGeneratedFileResponse>,
+        IRequestHandler<SourceGeneratedFileClosedRequest, SourceGeneratedFileClosedResponse>
+    {
+        private readonly OmniSharpWorkspace _workspace;
+        private readonly ILogger _logger;
+        private readonly Dictionary<DocumentId, VersionStamp> _lastSentVerisons = new();
+        private readonly object _lock = new();
+
+        [ImportingConstructor]
+        public SourceGeneratedFileService(OmniSharpWorkspace workspace, ILoggerFactory loggerFactory)
+        {
+            _workspace = workspace;
+            _logger = loggerFactory.CreateLogger<SourceGeneratedFileService>();
+        }
+
+        public async Task<SourceGeneratedFileResponse> Handle(SourceGeneratedFileRequest request)
+        {
+            var documentId = GetId(request);
+
+            var document = await _workspace.CurrentSolution.GetSourceGeneratedDocumentAsync(documentId, CancellationToken.None);
+
+            if (document is null)
+            {
+                _logger.LogError("Document with ID {0}:{1} was not found or not a source generated file", request.ProjectGuid, request.DocumentGuid);
+                return new SourceGeneratedFileResponse();
+            }
+
+            var text = await document.GetTextAsync();
+
+            var documentVerison = await document.GetTextVersionAsync();
+            lock (_lock)
+            {
+                _lastSentVerisons[documentId] = documentVerison;
+            }
+
+            return new SourceGeneratedFileResponse
+            {
+                Source = text.ToString(),
+                SourceName = document.FilePath
+            };
+        }
+
+        public async Task<UpdateSourceGeneratedFileResponse> Handle(UpdateSourceGeneratedFileRequest request)
+        {
+            var documentId = GetId(request);
+            var document = await _workspace.CurrentSolution.GetSourceGeneratedDocumentAsync(documentId, CancellationToken.None);
+            if (document == null)
+            {
+                lock (_lock)
+                {
+                    _ = _lastSentVerisons.Remove(documentId);
+                }
+                return new UpdateSourceGeneratedFileResponse() { UpdateType = UpdateType.Deleted };
+            }
+
+            var docVersion = await document.GetTextVersionAsync();
+            lock (_lock)
+            {
+                if (_lastSentVerisons.TryGetValue(documentId, out var lastVersion) && lastVersion == docVersion)
+                {
+                    return new UpdateSourceGeneratedFileResponse() { UpdateType = UpdateType.Unchanged };
+                }
+
+                _lastSentVerisons[documentId] = docVersion;
+            }
+
+            return new UpdateSourceGeneratedFileResponse()
+            {
+                UpdateType = UpdateType.Modified,
+                Source = (await document.GetTextAsync()).ToString()
+            };
+        }
+
+        public Task<SourceGeneratedFileClosedResponse> Handle(SourceGeneratedFileClosedRequest request)
+        {
+            lock (_lock)
+            {
+                _ = _lastSentVerisons.Remove(GetId(request));
+            }
+
+            return SourceGeneratedFileClosedResponse.Instance;
+        }
+
+        private DocumentId GetId(SourceGeneratedFileInfo info) => DocumentId.CreateFromSerialized(ProjectId.CreateFromSerialized(info.ProjectGuid), info.DocumentGuid);
+    }
+}

tests/OmniSharp.Roslyn.CSharp.Tests/AbstractGoToDefinitionFacts.cs

@@ -1,9 +1,12 @@
 using Microsoft.CodeAnalysis.CSharp;
 using Microsoft.CodeAnalysis.CSharp.Syntax;
+using Microsoft.CodeAnalysis.Diagnostics;
 using OmniSharp.Mef;
 using OmniSharp.Models.Metadata;
+using OmniSharp.Models.v1.SourceGeneratedFile;
 using OmniSharp.Roslyn.CSharp.Services.Navigation;
 using System.Collections.Generic;
+using System.Collections.Immutable;
 using System.Linq;
 using System.Threading.Tasks;
 using TestUtility;
@@ -506,6 +509,62 @@ public async Task ReturnsNoResultsButDoesNotThrowForNamespaces()
             Assert.Empty(GetInfo(response));
         }
 
+        [Fact]
+        public async Task ReturnsResultsForSourceGenerators()
+        {
+            const string Source = @"
+public class {|generatedClassName:Generated|}
+{
+    public int {|propertyName:Property|} { get; set; }
+}
+";
+            const string FileName = "real.cs";
+            TestFile generatedTestFile = new("GeneratedFile.cs", Source);
+            var testFile = new TestFile(FileName, @"
+class C
+{
+    public void M(Generated g)
+    {
+        _ = g.P$$roperty;
+    }
+}
+");
+
+            TestHelpers.AddProjectToWorkspace(SharedOmniSharpTestHost.Workspace,
+                "project.csproj",
+                new[] { "netcoreapp3.1" },
+                new[] { testFile },
+                analyzerRefs: ImmutableArray.Create<AnalyzerReference>(new TestGeneratorReference(
+                    context => context.AddSource("GeneratedFile", generatedTestFile.Content.Code))));
+
+            var point = testFile.Content.GetPointFromPosition();
+
+            var gotoDefRequest = CreateRequest(FileName, point.Line, point.Offset, wantMetadata: true);
+            var gotoDefHandler = GetRequestHandler(SharedOmniSharpTestHost);
+            var response = await gotoDefHandler.Handle(gotoDefRequest);
+            var info = GetInfo(response).Single();
+
+            Assert.NotNull(info.SourceGeneratorInfo);
+
+            var expectedSpan = generatedTestFile.Content.GetSpans("propertyName").Single();
+            var expectedRange = generatedTestFile.Content.GetRangeFromSpan(expectedSpan);
+
+            Assert.Equal(expectedRange.Start.Line, info.Line);
+            Assert.Equal(expectedRange.Start.Offset, info.Column);
+
+            var sourceGeneratedFileHandler = SharedOmniSharpTestHost.GetRequestHandler<SourceGeneratedFileService>(OmniSharpEndpoints.SourceGeneratedFile);
+            var sourceGeneratedRequest = new SourceGeneratedFileRequest
+            {
+                DocumentGuid = info.SourceGeneratorInfo.DocumentGuid,
+                ProjectGuid = info.SourceGeneratorInfo.ProjectGuid
+            };
+
+            var sourceGeneratedFileResponse = await sourceGeneratedFileHandler.Handle(sourceGeneratedRequest);
+            Assert.NotNull(sourceGeneratedFileResponse);
+            Assert.Equal(generatedTestFile.Content.Code, sourceGeneratedFileResponse.Source);
+            Assert.Equal(@"OmniSharp.Roslyn.CSharp.Tests\OmniSharp.Roslyn.CSharp.Tests.TestSourceGenerator\GeneratedFile.cs", sourceGeneratedFileResponse.SourceName.Replace("/", @"\"));
+        }
+
         protected async Task TestGoToSourceAsync(params TestFile[] testFiles)
         {
             var response = await GetResponseAsync(testFiles, wantMetadata: false);
@@ -581,6 +640,6 @@ protected async Task<TGotoDefinitionResponse> GetResponseAsync(TestFile[] testFi
 
         protected abstract TGotoDefinitionRequest CreateRequest(string fileName, int line, int column, bool wantMetadata, int timeout = 60000);
         protected abstract MetadataSource GetMetadataSource(TGotoDefinitionResponse response);
-        protected abstract IEnumerable<(int Line, int Column, string FileName)> GetInfo(TGotoDefinitionResponse response);
+        protected abstract IEnumerable<(int Line, int Column, string FileName, SourceGeneratedFileInfo SourceGeneratorInfo)> GetInfo(TGotoDefinitionResponse response);
     }
 }