feat: support roslyn lsp

[iabdelkareem]

I tried to integrate the new roslyn LSP but can't get it to work yet. The LSP seems to launch without issues; however, it never sends a workspace/projectInitializationComplete server event, so it can't be attached to buffers. Any help would be appreciated!

To use the roslyn lsp instead of omnisharp set lsp.use_omnisharp = false in the configurations and set cmd_path to the LSP binary.

[ViktorKarpilov]

Perhaps this might seem like a naive question (as I'm new to configuring NeoVim), but why you don't use the csharp-language-server. It stands as Roslyn based.

I`ve tried to fix issue by using other plugin for that task but had no success. Anyway maybe my code would be a little bit usefful

local M = {}
local config_store = require("csharp.config")
local logger = require("csharp.log")

local on_attach = function(client, bufnr)
  print("Attaching to Roslyn")
end

function M.start_roslyn(buffer, root)
  local function get_capabilities()
    local capabilities = vim.lsp.protocol.make_client_capabilities()
    capabilities.textDocument.completion.completionItem.snippetSupport = true
    local status_ok, cmp_nvim_lsp = pcall(require, "cmp_nvim_lsp")
    if status_ok then
      capabilities = cmp_nvim_lsp.default_capabilities(capabilities)
    end
    return capabilities
  end

  my_capabilities = get_capabilities()

  require("roslyn").setup({
    on_attach = on_attach,
    capabilities = my_capabilities,
  })

  require("mason-lspconfig").setup()
  require("mason-lspconfig").setup_handlers({
    -- The first entry (without a key) will be the default handler
    function(server_name)
      require("lspconfig")[server_name].setup({
        on_attach = on_attach,
        capabilities = my_capabilities,
      })
    end,
  })
  print("Roslyn launched client")
end

return M 

The script initiates the server and attempts to attach, but eventually, I encounter a "Client exit" message, and I'm unable to determine the cause due to the lack of logs.

[kmiterror]

Perhaps I will be able to help out.

Just to be sure: make sure you use neovim 0.10

add this plugins/roslyn.lua

return {
  "jmederosalvarado/roslyn.nvim",
}

and this config/lazy.lua

_G.on_attach = function(server_name)
  return function(_, bufnr)
    -- Create a command `:Format` local to the LSP buffer
    -- Set keymaps here so they only pertain to buffers that a lang server attaches too
    -- buffer=0 means only set for current buffer
    vim.api.nvim_buf_create_user_command(bufnr, "Format", function(_)
      if vim.lsp.buf.format then
        vim.lsp.buf.format()
      elseif vim.lsp.buf.formatting then
        vim.lsp.buf.formatting()
      end
    end, { desc = "Format current buffer with LSP" })

    vim.keymap.set("n", "K", vim.lsp.buf.hover, { buffer = 0 })
    vim.keymap.set("n", "gd", vim.lsp.buf.definition, { buffer = 0, desc = "LSP Go To Definition" })
    vim.keymap.set("n", "gt", vim.lsp.buf.type_definition, { buffer = 0, desc = "LSP Go to Type Definition" })
    vim.keymap.set("n", "gi", vim.lsp.buf.implementation, { buffer = 0, desc = "LSP Go to implementation" })
    vim.keymap.set(
      "n",
      "<leader>dl",
      "<cmd>Telescope diagnostics<cr>",
      { buffer = 0, desc = "LSP Telescope diagnostics" }
    )
    vim.keymap.set("n", "rn", ":lua vim.lsp.buf.rename()<cr>", { buffer = 0, desc = "LSP Rename Variable" })
    vim.keymap.set("n", "gc", ":lua vim.lsp.buf.code_action()<cr>", { buffer = 0, desc = "LSP Code action" })
    vim.keymap.set("n", "gD", ":lua vim.lsp.buf.declaration()<cr>", { buffer = 0, desc = "LSP Go To Declaration" })
    vim.keymap.set(
      "n",
      "gr",
      ":lua require('telescope.builtin').lsp_references()<cr>",
      { buffer = 0, desc = "LSP Telescope Find References" }
    )
    vim.keymap.set("n", "gR", ":lua vim.lsp.buf.references()<cr>", { buffer = 0, desc = "LSP Find References" })
    vim.keymap.set("n", "gs", ":lua vim.lsp.buf.signature_help()<cr>", { buffer = 0, desc = "LSP Signature" })
    -- Lesser used LSP functionality
    vim.keymap.set("n", "<leader>wl", ":lua print(vim.inspect(vim.lsp.buf.list_workspace_folders()))<cr>")
    vim.keymap.set("n", "<leader>wa", ":lua vim.lsp.buf.add_workspace_folder()<cr>")
    vim.keymap.set("n", "<leader>wr", ":lua vim.lsp.buf.remove_workspace_folder()<cr>")
    --Diagnostic keymaps
    vim.keymap.set("n", "[d", vim.diagnostic.goto_prev, { buffer = 0, desc = "Go to prev diagnostic" })
    vim.keymap.set("n", "]d", vim.diagnostic.goto_next, { buffer = 0, desc = "Go to next diagnostic" })
    vim.keymap.set("n", "<LocalLeader>do", vim.diagnostic.open_float, { buffer = 0, desc = "Diagnostics open float" })
    vim.keymap.set("n", "<leader>q", vim.diagnostic.setloclist, { buffer = 0, desc = "Set loc list" })
    vim.keymap.set("n", "<LocalLeader>dh", ":lua vim.diagnostic.hide()<CR>", { buffer = 0, desc = "Hide diagnostics" })
    vim.keymap.set("n", "<LocalLeader>ds", ":lua vim.diagnostic.show()<CR>", { buffer = 0, desc = "Show diagnostics" })
    vim.keymap.set("n", "<leader>F", ":lua vim.lsp.buf.format()<cr>", { buffer = 0, desc = "LSP Format" })
    vim.keymap.set(
      "n",
      "<leader>ls",
      ":lua require('telescope.builtin').lsp_document_symbols()<cr>",
      { buffer = 0, desc = "LSP document symbol" }
    )
    vim.keymap.set(
      "n",
      "<leader>ws",
      ":lua require('telescope.builtin').lsp_dynamic_workspace_symbols()<cr>",
      { buffer = 0, desc = "LSP workspace symbol" }
    )
  end
end

require("roslyn").setup({
  dotnet_cmd = "dotnet",
  roslyn_version = "4.11.0-2.24266.3",
  on_attach = _G.on_attach(vim.lsp),
  capabilities = nil,
})

after adding those files I believe you should re-start your neovim and call inside neovim :CSInstallRoslyn this might take few seconds, neovim will appear frozen

Once it's done installing roslyn, you should open a .cs file and it should start roslyn LSP

First you will see this message: Roslyn client initialized for target YourSolutionFile.sln and once it's done it will show: Roslyn project initialization complete