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 or Neovim. This language server is more stable and faster than OmniSharp.

This tool assists the use of Microsoft.CodeAnalysis.LanguageServer:

• Downloads Microsoft.CodeAnalysis.LanguageServer
• Launches Microsoft.CodeAnalysis.LanguageServer as a process
• 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.

Download the binaries that match your platform under Releases

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

The tool will download Microsoft.CodeAnalysis.LanguageServer at the first launch. It may take some seconds. To avoid this, you can run csharp-language-server --download before your first launch. This is useful for install scripts.

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

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

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

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 = 'csharp-language-server',
      cmd = {'csharp-language-server'},
      root_dir = root_dir,
    })
  end,
})

Override your omnisharp-config by setting this in settings:

"lsp": {
  "omnisharp": {
    "binary": {
      "path": "csharp-language-server"
    }
  }
}