roslyn-language-server

A wrapper around the language server behind the C# Visual Studio Code extension, Microsoft.CodeAnalysis.LanguageServer, which makes it compatible with other editors, e.g., Helix. This is more stable and faster than OmniSharp.

This tool works around the quirks of Microsoft.CodeAnalysis.LanguageServer in the following way:

• Installs Microsoft.CodeAnalysis.LanguageServer in ~/.roslyn
• Launches Microsoft.CodeAnalysis.LanguageServer as a process
• Passes the provided unix socket or named pipe and forwards all communication to stdio
• Waits for capabilities notification from the server, and forces pull diagnostics to be available. This forces the server respect clients who do not support dynamic registration of diagnostic capabilities.
• Waits for an initialize notification from the client, and finds relevant .sln or .csproj files and sends them to the server as a custom open notification.

Installation

Binaries

Download the binaries that matches your platform under Releases

Nix

If you use nix, you can use this repository's nix flake.

Others

Alternatively, install with cargo: cargo install --git https://github.com/SofusA/roslyn-language-server

Usage

Helix

Since Microsoft.CodeAnalysis.LanguageServer only supports pull diagnostics and Helix does not (yet), you would need to use my branch at github:sofusa/helix-pull-diagnostics.

[language-server.roslyn]
command = "roslyn-language-server"

[[language]]
name = "c-sharp"
language-servers = ["roslyn"]

Neovim

vim.api.nvim_create_autocmd('FileType', {
  pattern = 'cs',
  callback = function(args)
    local root_dir = vim.fs.dirname(
      vim.fs.find({ '.sln', '.csproj', '.git' }, { upward = true })[1]
    )
    vim.lsp.start({
      name = 'roslyn-language-server',
      cmd = {'roslyn-language-server'},
      root_dir = root_dir,
    })
  end,
})