[Omnisharp-LSP] textDocument/documentHighlight support (#999)

* Add handler scaffold

* More stuff

* Make handler work

* Add copyright

* Add tests, fix bugs

* Fix small issues

Author: Robert Holt

src/PowerShellEditorServices.Engine/LanguageServer/OmnisharpLanguageServer.cs

@@ -1,3 +1,8 @@
+//
+// Copyright (c) Microsoft. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+//
+
 using System.IO.Pipes;
 using System.Reflection;
 using System.Threading.Tasks;
@@ -8,6 +13,7 @@
 using System.Security.AccessControl;
 using OmniSharp.Extensions.LanguageServer.Server;
 using PowerShellEditorServices.Engine.Services.Handlers;
+using Microsoft.PowerShell.EditorServices.TextDocument;
 
 namespace Microsoft.PowerShell.EditorServices.Engine
 {
@@ -56,18 +62,26 @@ public async Task StartAsync()
                     _configuration.OutNamedPipeName,
                     out NamedPipeServerStream outNamedPipe);
 
+                ILogger logger = options.LoggerFactory.CreateLogger("OptionsStartup");
+
+                logger.LogInformation("Waiting for connection");
                 namedPipe.WaitForConnection();
                 if (outNamedPipe != null)
                 {
                     outNamedPipe.WaitForConnection();
                 }
 
+                logger.LogInformation("Connected");
+
                 options.Input = namedPipe;
                 options.Output = outNamedPipe ?? namedPipe;
 
                 options.LoggerFactory = _configuration.LoggerFactory;
                 options.MinimumLogLevel = _configuration.MinimumLogLevel;
                 options.Services = _configuration.Services;
+
+                logger.LogInformation("Adding handlers");
+
                 options
                     .WithHandler<WorkspaceSymbolsHandler>()
                     .WithHandler<TextDocumentHandler>()
@@ -77,7 +91,10 @@ public async Task StartAsync()
                     .WithHandler<DocumentFormattingHandler>()
                     .WithHandler<DocumentRangeFormattingHandler>()
                     .WithHandler<ReferencesHandler>()
-                    .WithHandler<DocumentSymbolHandler>();
+                    .WithHandler<DocumentSymbolHandler>()
+                    .WithHandler<DocumentHighlightHandler>();
+
+                logger.LogInformation("Handlers added");
             });
 
             _serverStart.SetResult(true);

src/PowerShellEditorServices.Engine/Services/Symbols/SymbolsService.cs

@@ -1,6 +1,12 @@
+//
+// Copyright (c) Microsoft. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+//
+
 using System;
 using System.Collections.Generic;
 using System.Collections.Specialized;
+using System.Linq;
 using System.Runtime.InteropServices;
 using Microsoft.Extensions.Logging;
 using Microsoft.PowerShell.EditorServices.Symbols;
@@ -47,8 +53,6 @@ public SymbolsService(
 
         #endregion
 
-
-
         /// <summary>
         /// Finds all the symbols in a file.
         /// </summary>
@@ -176,5 +180,33 @@ public List<SymbolReference> FindReferencesOfSymbol(
 
             return symbolReferences;
         }
+
+        /// <summary>
+        /// Finds all the occurences of a symbol in the script given a file location
+        /// </summary>
+        /// <param name="file">The details and contents of a open script file</param>
+        /// <param name="symbolLineNumber">The line number of the cursor for the given script</param>
+        /// <param name="symbolColumnNumber">The coulumn number of the cursor for the given script</param>
+        /// <returns>FindOccurrencesResult</returns>
+        public IReadOnlyList<SymbolReference> FindOccurrencesInFile(
+            ScriptFile file,
+            int symbolLineNumber,
+            int symbolColumnNumber)
+        {
+            SymbolReference foundSymbol = AstOperations.FindSymbolAtPosition(
+                file.ScriptAst,
+                symbolLineNumber,
+                symbolColumnNumber);
+
+            if (foundSymbol == null)
+            {
+                return null;
+            }
+
+            return AstOperations.FindReferencesOfSymbol(
+                file.ScriptAst,
+                foundSymbol,
+                needsAliases: false).ToArray();
+        }
     }
 }

src/PowerShellEditorServices.Engine/Services/TextDocument/Handlers/DocumentHighlightHandler.cs

@@ -0,0 +1,86 @@
+//
+// Copyright (c) Microsoft. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+//
+
+using Microsoft.Extensions.Logging;
+using Microsoft.PowerShell.EditorServices.Symbols;
+using OmniSharp.Extensions.LanguageServer.Protocol.Client.Capabilities;
+using OmniSharp.Extensions.LanguageServer.Protocol.Models;
+using OmniSharp.Extensions.LanguageServer.Protocol.Server;
+using PowerShellEditorServices.Engine.Utility;
+using System.Collections.Generic;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace Microsoft.PowerShell.EditorServices.TextDocument
+{
+    public class DocumentHighlightHandler : IDocumentHighlightHandler
+    {
+        private static readonly DocumentHighlightContainer s_emptyHighlightContainer = new DocumentHighlightContainer();
+
+        private readonly ILogger _logger;
+
+        private readonly WorkspaceService _workspaceService;
+
+        private readonly SymbolsService _symbolsService;
+
+        private readonly TextDocumentRegistrationOptions _registrationOptions;
+
+        private DocumentHighlightCapability _capability;
+
+        public DocumentHighlightHandler(
+            ILoggerFactory loggerFactory,
+            WorkspaceService workspaceService,
+            SymbolsService symbolService)
+        {
+            _logger = loggerFactory.CreateLogger<OmniSharp.Extensions.LanguageServer.Protocol.Server.DocumentHighlightHandler>();
+            _workspaceService = workspaceService;
+            _symbolsService = symbolService;
+            _registrationOptions = new TextDocumentRegistrationOptions()
+            {
+                DocumentSelector = new DocumentSelector(new DocumentFilter() { Pattern = "**/*.ps*1" } )
+            };
+            _logger.LogInformation("highlight handler loaded");
+        }
+
+        public TextDocumentRegistrationOptions GetRegistrationOptions()
+        {
+            return _registrationOptions;
+        }
+
+        public Task<DocumentHighlightContainer> Handle(
+            DocumentHighlightParams request,
+            CancellationToken cancellationToken)
+        {
+            ScriptFile scriptFile = _workspaceService.GetFile(PathUtils.FromUri(request.TextDocument.Uri));
+
+            IReadOnlyList<SymbolReference> symbolOccurrences = _symbolsService.FindOccurrencesInFile(
+                scriptFile,
+                (int)request.Position.Line,
+                (int)request.Position.Character);
+
+            if (symbolOccurrences == null)
+            {
+                return Task.FromResult(s_emptyHighlightContainer);
+            }
+
+            var highlights = new DocumentHighlight[symbolOccurrences.Count];
+            for (int i = 0; i < symbolOccurrences.Count; i++)
+            {
+                highlights[i] = new DocumentHighlight
+                {
+                    Kind = DocumentHighlightKind.Write, // TODO: Which symbol types are writable?
+                    Range = symbolOccurrences[i].ScriptRegion.ToRange()
+                };
+            }
+
+            return Task.FromResult(new DocumentHighlightContainer(highlights));
+        }
+
+        public void SetCapability(DocumentHighlightCapability capability)
+        {
+            _capability = capability;
+        }
+    }
+}

src/PowerShellEditorServices.Engine/Services/TextDocument/ScriptFileMarker.cs

@@ -139,20 +139,21 @@ internal static ScriptFileMarker FromDiagnosticRecord(PSObject psObject)
 
             if (diagnosticRecord.SuggestedCorrections != null)
             {
-                var suggestedCorrections = diagnosticRecord.SuggestedCorrections as dynamic;
-                List<ScriptRegion> editRegions = new List<ScriptRegion>();
+                var editRegions = new List<ScriptRegion>();
                 string correctionMessage = null;
-                foreach (var suggestedCorrection in suggestedCorrections)
+                foreach (dynamic suggestedCorrection in diagnosticRecord.SuggestedCorrections)
                 {
-                    editRegions.Add(new ScriptRegion
-                    {
-                        File = diagnosticRecord.ScriptPath,
-                        Text = suggestedCorrection.Text,
-                        StartLineNumber = suggestedCorrection.StartLineNumber,
-                        StartColumnNumber = suggestedCorrection.StartColumnNumber,
-                        EndLineNumber = suggestedCorrection.EndLineNumber,
-                        EndColumnNumber = suggestedCorrection.EndColumnNumber
-                    });
+                    editRegions.Add(
+                        new ScriptRegion(
+                            diagnosticRecord.ScriptPath,
+                            suggestedCorrection.Text,
+                            suggestedCorrection.StartLineNumber,
+                            suggestedCorrection.StartColumnNumber,
+                            startOffset: -1,
+                            suggestedCorrection.EndLineNumber,
+                            suggestedCorrection.EndColumnNumber,
+                            endOffset: -1));
+
                     correctionMessage = suggestedCorrection.Description;
                 }