Return generated file info for find references (#2434)

Allows find references to provide information about references in source-generated files.

src/OmniSharp.Roslyn.CSharp/Helpers/LocationExtensions.cs

@@ -2,9 +2,9 @@
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
-using System.Threading.Tasks;
 using Microsoft.CodeAnalysis;
 using Microsoft.CodeAnalysis.Text;
+using OmniSharp.Extensions;
 using OmniSharp.Models;
 
 namespace OmniSharp.Helpers
@@ -24,20 +24,26 @@ public static QuickFix GetQuickFix(this Location location, OmniSharpWorkspace wo
             var sourceText = GetSourceText(location, documents, lineSpan.HasMappedPath);
             var text = GetLineText(location, sourceText, lineSpan.StartLinePosition.Line);
 
-            var fileName = Path.IsPathRooted(lineSpan.Path)
+            var generatedInfo = workspace.CurrentSolution.GetSourceGeneratedFileInfo(location);
+
+            var fileName = Path.IsPathRooted(lineSpan.Path) || generatedInfo != null
+                // If there is generated file information, the path is not rooted, but we don't want to try and locate it as it doesn't
+                // exist on disk
                 ? lineSpan.Path
                 // when a #line directive maps into a separate file using a relative path, get the full path relative to the folder containing the source tree
                 : Path.GetFullPath(Path.Combine(Path.GetDirectoryName(location.SourceTree.FilePath), lineSpan.Path));
 
-            return new QuickFix
+
+            return new SymbolLocation
             {
                 Text = text.Trim(),
                 FileName = fileName,
                 Line = lineSpan.StartLinePosition.Line,
                 Column = lineSpan.HasMappedPath ? 0 : lineSpan.StartLinePosition.Character, // when a #line directive maps into a separate file, assume columns (0,0)
                 EndLine = lineSpan.EndLinePosition.Line,
                 EndColumn = lineSpan.HasMappedPath ? 0 : lineSpan.EndLinePosition.Character,
-                Projects = documents.Select(document => document.Project.Name).ToArray()
+                Projects = documents.Select(document => document.Project.Name).ToArray(),
+                GeneratedFileInfo = generatedInfo
             };
 
             static SourceText GetSourceText(Location location, IEnumerable<Document> documents, bool hasMappedPath)

src/OmniSharp.Roslyn/Extensions/SolutionExtensions.cs

@@ -96,7 +96,7 @@ private static QuickFix ConvertSymbol(Solution solution, ISymbol symbol, Locatio
             };
         }
 
-        internal static SourceGeneratedFileInfo? GetSourceGeneratedFileInfo(Solution solution, Location location)
+        internal static SourceGeneratedFileInfo? GetSourceGeneratedFileInfo(this Solution solution, Location location)
         {
             Debug.Assert(location.IsInSource);
             var document = solution.GetDocument(location.SourceTree);

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

@@ -1,11 +1,15 @@
 using System.Collections.Generic;
+using System.Collections.Immutable;
 using System.IO;
 using System.Linq;
 using System.Threading.Tasks;
 using Microsoft.CodeAnalysis;
+using Microsoft.CodeAnalysis.Diagnostics;
 using OmniSharp.Models;
 using OmniSharp.Models.FindUsages;
+using OmniSharp.Models.v1.SourceGeneratedFile;
 using OmniSharp.Roslyn.CSharp.Services.Navigation;
+using Roslyn.Test.Utilities;
 using TestUtility;
 using Xunit;
 using Xunit.Abstractions;
@@ -545,6 +549,49 @@ public class Foo
             Assert.Null(exception);
         }
 
+        [Fact]
+        public async Task ReturnsGeneratedReferences()
+        {
+            const string Source = @"
+public partial class Generated
+{
+    public int Property { get; set; }
+}
+";
+            const string FileName = "real.cs";
+            var testFile = new TestFile(FileName, @"
+class C
+{
+    Generate$$d G;
+}
+");
+
+            TestHelpers.AddProjectToWorkspace(SharedOmniSharpTestHost.Workspace,
+                "project.csproj",
+                new[] { "netcoreapp3.1" },
+                new[] { testFile },
+                analyzerRefs: ImmutableArray.Create<AnalyzerReference>(new TestGeneratorReference(
+                    context => context.AddSource("GeneratedFile", Source))));
+
+            var response = await FindUsagesAsync(testFile, onlyThisFile: false, excludeDefinition: false);
+
+            var result = response.QuickFixes.Cast<SymbolLocation>().Single(s => s.GeneratedFileInfo is not null);
+            Assert.NotNull(result);
+            AssertEx.Equal(@"OmniSharp.Roslyn.CSharp.Tests\OmniSharp.Roslyn.CSharp.Tests.TestSourceGenerator\GeneratedFile.cs", result.FileName.Replace("/", @"\"));
+
+            var sourceGeneratedFileHandler = SharedOmniSharpTestHost.GetRequestHandler<SourceGeneratedFileService>(OmniSharpEndpoints.SourceGeneratedFile);
+            var sourceGeneratedRequest = new SourceGeneratedFileRequest
+            {
+                DocumentGuid = result.GeneratedFileInfo.DocumentGuid,
+                ProjectGuid = result.GeneratedFileInfo.ProjectGuid
+            };
+
+            var sourceGeneratedFileResponse = await sourceGeneratedFileHandler.Handle(sourceGeneratedRequest);
+            Assert.NotNull(sourceGeneratedFileResponse);
+            AssertEx.Equal(Source, sourceGeneratedFileResponse.Source);
+            AssertEx.Equal(@"OmniSharp.Roslyn.CSharp.Tests\OmniSharp.Roslyn.CSharp.Tests.TestSourceGenerator\GeneratedFile.cs", sourceGeneratedFileResponse.SourceName.Replace("/", @"\"));
+        }
+
         private Task<QuickFixResponse> FindUsagesAsync(string code, bool excludeDefinition = false)
         {
             return FindUsagesAsync(new[] { new TestFile("dummy.cs", code) }, false, excludeDefinition);