LSP: wire up handler for codeAction

CHANGELOG.md

@@ -1,7 +1,8 @@
 # Changelog
 All changes to the project will be documented in this file.
 
-## [1.35.3] - Not yet released
+## [1.35.3] - not yet released
+* Added LSP handler for `textDocument/codeAction` request. (PR: [#1795](https://github.com/OmniSharp/omnisharp-roslyn/pull/1795))
 
 ## [1.35.2] - 2020-05-20
 * Added support for `WarningsAsErrors` in csproj files (PR: [#1779](https://github.com/OmniSharp/omnisharp-roslyn/pull/1779))

src/OmniSharp.LanguageServerProtocol/Handlers/OmniSharpCodeActionHandler.cs

@@ -0,0 +1,101 @@
+using System;
+using System.Linq;
+using System.Collections.Generic;
+using System.Threading;
+using System.Threading.Tasks;
+using OmniSharp.Extensions.JsonRpc;
+using OmniSharp.Extensions.LanguageServer.Protocol.Models;
+using OmniSharp.Extensions.LanguageServer.Protocol.Server;
+using OmniSharp.Models;
+using OmniSharp.Models.V2.CodeActions;
+
+namespace OmniSharp.LanguageServerProtocol.Handlers
+{
+    internal sealed class OmniSharpCodeActionHandler: CodeActionHandler
+    {
+        public static IEnumerable<IJsonRpcHandler> Enumerate(RequestHandlers handlers)
+        {
+            foreach (var (selector, getActionsHandler, runActionHandler) in handlers
+                     .OfType<Mef.IRequestHandler<GetCodeActionsRequest, GetCodeActionsResponse>,
+                             Mef.IRequestHandler<RunCodeActionRequest, RunCodeActionResponse>>())
+            {
+                yield return new OmniSharpCodeActionHandler(getActionsHandler, runActionHandler, selector);
+            }
+        }
+
+        private readonly Mef.IRequestHandler<GetCodeActionsRequest, GetCodeActionsResponse> _getActionsHandler;
+        private readonly Mef.IRequestHandler<RunCodeActionRequest, RunCodeActionResponse> _runActionHandler;
+
+        public OmniSharpCodeActionHandler(
+            Mef.IRequestHandler<GetCodeActionsRequest, GetCodeActionsResponse> getActionsHandler,
+            Mef.IRequestHandler<RunCodeActionRequest, RunCodeActionResponse> runActionHandler,
+            DocumentSelector documentSelector)
+            : base(new CodeActionRegistrationOptions()
+            {
+                DocumentSelector = documentSelector,
+                CodeActionKinds = new Container<CodeActionKind>(
+                    CodeActionKind.SourceOrganizeImports,
+                    CodeActionKind.Refactor,
+                    CodeActionKind.RefactorExtract),
+            })
+        {
+            _getActionsHandler = getActionsHandler;
+            _runActionHandler = runActionHandler;
+        }
+
+        public async override Task<CommandOrCodeActionContainer> Handle(CodeActionParams request, CancellationToken cancellationToken)
+        {
+            var omnisharpRequest = new GetCodeActionsRequest {
+                FileName = Helpers.FromUri(request.TextDocument.Uri),
+                Column = (int)request.Range.Start.Character,
+                Line = (int)request.Range.Start.Line,
+                Selection = Helpers.FromRange(request.Range),
+            };
+
+            var omnisharpResponse = await _getActionsHandler.Handle(omnisharpRequest);
+
+            var codeActions = new List<CodeAction>();
+
+            foreach (var ca in omnisharpResponse.CodeActions)
+            {
+                var omnisharpCaRequest = new RunCodeActionRequest {
+                    Identifier = ca.Identifier,
+                    FileName = Helpers.FromUri(request.TextDocument.Uri),
+                    Column = Convert.ToInt32(request.Range.Start.Character),
+                    Line = Convert.ToInt32(request.Range.Start.Line),
+                    Selection = Helpers.FromRange(request.Range),
+                    ApplyTextChanges = false,
+                    WantsTextChanges = true,
+                };
+
+                var omnisharpCaResponse = await _runActionHandler.Handle(omnisharpCaRequest);
+
+                var changes = omnisharpCaResponse.Changes.ToDictionary(
+                    x => Helpers.ToUri(x.FileName),
+                    x => ((ModifiedFileResponse)x).Changes.Select(edit => new TextEdit
+                    {
+                        NewText = edit.NewText,
+                        Range = Helpers.ToRange((edit.StartColumn, edit.StartLine), (edit.EndColumn, edit.EndLine))
+                    }));
+
+                CodeActionKind kind;
+                if (ca.Identifier.StartsWith("using ")) { kind = CodeActionKind.SourceOrganizeImports; }
+                else if (ca.Identifier.StartsWith("Inline ")) { kind = CodeActionKind.RefactorInline; }
+                else if (ca.Identifier.StartsWith("Extract ")) { kind = CodeActionKind.RefactorExtract; }
+                else if (ca.Identifier.StartsWith("Change ")) { kind = CodeActionKind.QuickFix; }
+                else { kind = CodeActionKind.Refactor; }
+
+                codeActions.Add(
+                    new CodeAction {
+                        Title = ca.Name,
+                        Kind = kind,
+                        Diagnostics = new Container<Diagnostic>(),
+                        Edit = new WorkspaceEdit { Changes = changes, }
+                    });
+            }
+
+            return new CommandOrCodeActionContainer(
+                codeActions.Select(ca => new CommandOrCodeAction(ca)));
+        }
+    }
+}

src/OmniSharp.LanguageServerProtocol/Helpers.cs

@@ -40,6 +40,23 @@ public static Range ToRange(this QuickFix location)
             };
         }
 
+        public static OmniSharp.Models.V2.Range FromRange(Range range)
+        {
+            return new OmniSharp.Models.V2.Range
+            {
+                Start = new OmniSharp.Models.V2.Point
+                {
+                    Column = Convert.ToInt32(range.Start.Character),
+                    Line = Convert.ToInt32(range.Start.Line),
+                },
+                End = new OmniSharp.Models.V2.Point
+                {
+                    Column = Convert.ToInt32(range.End.Character),
+                    Line = Convert.ToInt32(range.End.Line),
+                },
+            };
+        }
+
         public static DiagnosticSeverity ToDiagnosticSeverity(string logLevel)
         {
             // We stringify this value and pass to clients

src/OmniSharp.LanguageServerProtocol/LanguageServerHost.cs

@@ -166,6 +166,7 @@ private Task Initialize(Extensions.LanguageServer.Server.ILanguageServer server,
                 .Concat(OmniSharpDocumentSymbolHandler.Enumerate(_handlers))
                 .Concat(OmniSharpReferencesHandler.Enumerate(_handlers))
                 .Concat(OmniSharpCodeLensHandler.Enumerate(_handlers))
+                .Concat(OmniSharpCodeActionHandler.Enumerate(_handlers))
                 .Concat(OmniSharpDocumentFormattingHandler.Enumerate(_handlers))
                 .Concat(OmniSharpDocumentFormatRangeHandler.Enumerate(_handlers))
                 .Concat(OmniSharpDocumentOnTypeFormatHandler.Enumerate(_handlers)))