LSP Mode does not seem to work with OmniSharp Client

[groogiam]

I am trying to use the OmniSharp C# Language Client to get diagnostic information about a C# project. So far I have been unsuccessful in this attempt.

I have been able to start the omnisharp service and initialize but OnPublishDiagnostics never seems to fire. When attempting to open and change a document I get an exception on the server.

at OmniSharp.Cake.Services.CakeScriptService.Generate(FileChange fileChange) in D:\a\1\s\src\OmniSharp.Cake\Services\CakeScriptService.cs:line 55

I am not sure if this is an issue with the server, the client or me just understanding the protocol. Any guidance you could provide on the issue would be much appreciated. The code for my sample is below.

using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.IO;
using System.Linq;
using System.Threading;
using System.Threading.Tasks;
using OmniSharp.Extensions.LanguageServer.Client;
using OmniSharp.Extensions.LanguageServer.Protocol.Models;

namespace OmniSharpClient
{
    class Program
    {
        static async Task Main(string[] args)
        {
            var loggerFactory = new Microsoft.Extensions.Logging.LoggerFactory();

            var omniSharpInfo = new ProcessStartInfo
            {
                FileName = @"C:\Users\username\OneDrive\Scratch\LangServer\omnisharp-win-x64\OmniSharp.exe",
                Arguments = @"-lsp cake:enabled=false"
                //Arguments = @"-s C:\Users\username\Desktop\LangServer\ConsoleTest"
            };

            var cancellationSource = new CancellationTokenSource();
            cancellationSource.CancelAfter(TimeSpan.FromSeconds(30));

            using (var client = new LanguageClient(loggerFactory, omniSharpInfo))
            {
                client.Window.OnLogMessage((string message, MessageType messageType) =>
                {
                    Console.WriteLine(message);
                });

                client.TextDocument.OnPublishDiagnostics(DiagnosticPublished);
                Console.WriteLine("Init...");
                await client.Initialize(
                                workspaceRoot: @"C:\Users\username\OneDrive\Scratch\LangServer\ConsoleTest",
                                initializationOptions: new { }, // If the server requires initialisation options, you pass them here.
                                cancellationToken: cancellationSource.Token
                            );

                await client.IsReady;

                await Task.Delay(10000);

                var fileName = @"C:\Users\username\OneDrive\Scratch\LangServer\ConsoleTest\Program.cs";

                client.TextDocument.DidOpen(fileName, "csharp"); //File.ReadAllText(fileName)
                await Task.Delay(3000);
                //client.TextDocument.DidClose(fileName);
                client.TextDocument.DidChange(fileName, "csharp", 1);

                await Task.Delay(10000);

                Console.WriteLine("Shutdown...");
                await client.Shutdown();
            }
        }

        public static void DiagnosticPublished(Uri documentUri, List<Diagnostic> diagnostics)
        {
            Console.WriteLine(documentUri);
        }
    }
}

[bjorkstromm]

This was caused by an issue in the LSP libs here OmniSharp/csharp-language-server-protocol#156 will be fixed via #1562

[bjorkstromm]

Fixed via #1562 and available in latest release https://github.com/OmniSharp/omnisharp-roslyn/releases/tag/v1.34.3