LSP: expose omnisharp/client/findReferences custom command for code lenses

CHANGELOG.md

@@ -3,6 +3,7 @@ All changes to the project will be documented in this file.
 
 ## [1.35.3] - not yet released
 * Added LSP handler for `textDocument/codeAction` request. (PR: [#1795](https://github.com/OmniSharp/omnisharp-roslyn/pull/1795))
+* Expose a custom LSP `omnisharp/client/findReferences` command via code lens (meant to be handled by LSP client). (PR: [#1807](https://github.com/OmniSharp/omnisharp-roslyn/pull/1807))
 
 ## [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/OmniSharpCodeLensHandler.cs

@@ -3,7 +3,9 @@
 using System.Linq;
 using System.Threading;
 using System.Threading.Tasks;
+using Newtonsoft.Json;
 using Newtonsoft.Json.Linq;
+using Newtonsoft.Json.Serialization;
 using OmniSharp.Extensions.JsonRpc;
 using OmniSharp.Extensions.LanguageServer.Protocol;
 using OmniSharp.Extensions.LanguageServer.Protocol.Client.Capabilities;
@@ -78,10 +80,23 @@ public async override Task<CodeLens> Handle(CodeLens request, CancellationToken
 
             var length = omnisharpResponse?.QuickFixes?.Count() ?? 0;
 
+            var jsonCamelCaseContract = new JsonSerializer {
+                ContractResolver = new CamelCasePropertyNamesContractResolver()
+            };
+
             request.Command = new Command
             {
-                Title = length == 1 ? "1 reference" : $"{length} references"
-                // TODO: Hook up command.
+                Title = length == 1 ? "1 reference" : $"{length} references",
+                Name = "omnisharp/client/findReferences",
+                Arguments = new JArray(
+                    new [] {
+                        JObject.FromObject(
+                            new Location {
+                                Uri = request.Data.ToObject<Uri>(),
+                                Range = request.Range,
+                            },
+                            jsonCamelCaseContract)
+                    }),
             };
 
             return request;

src/OmniSharp.LanguageServerProtocol/Handlers/OmniSharpExecuteCommandHandler.cs

@@ -0,0 +1,31 @@
+using System.Collections.Generic;
+using System.Threading;
+using System.Threading.Tasks;
+using MediatR;
+using OmniSharp.Extensions.JsonRpc;
+using OmniSharp.Extensions.LanguageServer.Protocol.Models;
+using OmniSharp.Extensions.LanguageServer.Protocol.Server;
+
+namespace OmniSharp.LanguageServerProtocol.Handlers
+{
+    class OmniSharpExecuteCommandHandler : ExecuteCommandHandler
+    {
+        public static IEnumerable<IJsonRpcHandler> Enumerate(RequestHandlers handlers)
+        {
+            yield return new OmniSharpExecuteCommandHandler();
+        }
+
+        public OmniSharpExecuteCommandHandler()
+            : base (new ExecuteCommandRegistrationOptions() {
+                Commands = new Container<string>(),
+            })
+        {
+        }
+
+        public override Task<Unit>
+        Handle(ExecuteCommandParams request, CancellationToken cancellationToken)
+        {
+            return Task.FromResult(Unit.Value);
+        }
+    }
+}

src/OmniSharp.LanguageServerProtocol/LanguageServerHost.cs

@@ -169,6 +169,7 @@ private Task Initialize(Extensions.LanguageServer.Server.ILanguageServer server,
                 .Concat(OmniSharpCodeActionHandler.Enumerate(_handlers))
                 .Concat(OmniSharpDocumentFormattingHandler.Enumerate(_handlers))
                 .Concat(OmniSharpDocumentFormatRangeHandler.Enumerate(_handlers))
+                .Concat(OmniSharpExecuteCommandHandler.Enumerate(_handlers))
                 .Concat(OmniSharpDocumentOnTypeFormatHandler.Enumerate(_handlers)))
             {
                 server.AddHandlers(handler);