Easy way to set up Neovim Native LSP

Neovim-Native-Lsp.md

NVIM LSP setup

Easy Guide on Setting Native Neovim LSP with Lua

Prerequisites

• Node.js & npm
• package manager for nvim (recommended: Packer ) you can also use lazy or Vim-Plug

Install required packages

Using Packer

    use 'neovim/nvim-lspconfig'
    use 'williamboman/mason.nvim'
    use 'williamboman/mason-lspconfig.nvim'
    use 'hrsh7th/nvim-cmp'
    use 'hrsh7th/cmp-nvim-lsp'
    use 'hrsh7th/cmp-path'
    use 'L3MON4D3/LuaSnip'
    use 'saadparwaiz1/cmp_luasnip'
    use 'ray-x/lsp_signature.nvim'
    use 'RRethy/vim-illuminate'

Now create a file named lsp-handlers.lua inside lua/user/ direcotry and paste the following:

local M = {}

local status_cmp_ok, cmp_nvim_lsp = pcall(require, "cmp_nvim_lsp")
if not status_cmp_ok then
    vim.notify "cmp_nvim_lsp plugin not found"
    return
end

local signature_status, lsp_signature = pcall(require, "lsp_signature")
if not signature_status then
    vim.notify "lsp_signature plugin not found"
    return
end

local illuminate_status, illuminate = pcall(require, "illuminate")
if not illuminate_status then
    vim.notify "illuminate plugin not found"
    return
end

local opts = { noremap = true, silent = true }
local keymap = vim.api.nvim_buf_set_keymap

local lsp_keymaps = function(bufnr)
    keymap(bufnr, "n", "<leader>gd", "<cmd>lua vim.lsp.buf.declaration()<CR>", opts)
    keymap(bufnr, "n", "<leader>gD", "<cmd>lua vim.lsp.buf.definition()<CR>", opts)
    keymap(bufnr, "n", "<leader>gim", "<cmd>lua vim.lsp.buf.implementation()<CR>", opts)
    keymap(bufnr, "n", "<leader>gr", "<cmd>lua vim.lsp.buf.references()<CR>", opts)
    keymap(bufnr, "n", "<leader>ca", "<cmd>lua vim.lsp.buf.code_action()<CR>", opts)
    keymap(bufnr, "n", "<leader>r", "<cmd>lua vim.lsp.buf.rename()<CR>", opts)
    keymap(bufnr, "n", "<C-h>", "<cmd>lua vim.lsp.buf.signature_help()<CR>", opts)
    keymap(bufnr, "n", "K", "<cmd>lua vim.lsp.buf.hover()<CR>", opts)

    keymap(bufnr, "n", "<leader>e", "<cmd>lua vim.diagnostic.open_float()<CR>", opts)
    keymap(bufnr, "n", "<C-n>", "<cmd>lua vim.diagnostic.goto_next({buffer=0})<CR>", opts)
    keymap(bufnr, "n", "<C-p>", "<cmd>lua vim.diagnostic.goto_prev({buffer=0})<CR>", opts)
end

local signature_cfg = {
    hint_enable = false,
    floating_window = true,
    check_completion_visible = true,
    toggle_key = '<M-t>',
    select_signature_key = '<M-s>',
}

M.capabilities = cmp_nvim_lsp.default_capabilities()

M.on_attach = function(client, bufnr)
    if client.name == "tsserver" then
        client.server_capabilities.documentFormattingProvider = false -- comment this if you are not using null-ls for formatting;
    end

    client.server_capabilities.semanticTokensProvider = nil

    lsp_keymaps(bufnr)

    illuminate.on_attach(client)

    lsp_signature.on_attach(signature_cfg, bufnr)
end

return M

• We could have put these inside our lsp file but this way we can reuse this file in language specific config also
• Change the keymaps according to your liking
• I have excluded formatting bind as i use format on save i.e.

vim.cmd [[autocmd BufWritePre * lua vim.lsp.buf.format()]] -- put this on your init.lua file

Create a folder lsp in lua/user/ directory

Create a file named nvim-lsp.lua in lua/user/lsp/ directory and paste the following

local mason_status, mason = pcall(require, "mason")
if not mason_status then
    return
end

local mason_lsp_status, masonlsp = pcall(require, "mason-lspconfig")
if not mason_lsp_status then
    return
end

local lsp_status, lspconf = pcall(require, "lspconfig")
if not lsp_status then
    return
end

local servers = {
    'sumneko_lua',
    'tsserver',
                 -- add other lsp server name here
}

mason.setup {
    ui = {
        border = "none",
        icons = {
            package_installed = "✓",
            package_pending = "➜",
            package_uninstalled = "✗"
        },
    },
    log_level = vim.log.levels.INFO,
    max_concurrent_installers = 4,
}

masonlsp.setup {
    ensure_installed = servers,
    automatic_installation = true,
}

for _, lsp in pairs(servers) do
    lspconf[lsp].setup {
        on_attach = require("user.lsp-handlers").on_attach,
        capabilities = require("user.lsp-handlers").capabilities,
        flags = {
            debounce_text_changes = 150,
        },
        settings = {
            Lua = {
                diagnostics = {
                    globals = { 'vim' }
                }
            }
        }
    }
end

• You can see available language servers from here and add that inside servers table above

Create a file nvim-cmp.lua in lua/user/lsp/ and paste the following

local luaship_status, luasnip = pcall(require, "luasnip")
if not luaship_status then
    return
end

local cmp_status, cmp = pcall(require, "cmp")
if not cmp_status then
    return
end

local snippet_status, csnip = pcall(require, "luasnip/loaders/from_vscode")
if not snippet_status then
    return
end

local kind_icons = {
    Text = "",
    Method = "m",
    Function = "",
    Constructor = "",
    Field = "",
    Variable = "",
    Class = "",
    Interface = "",
    Module = "",
    Property = "",
    Unit = "",
    Value = "",
    Enum = "",
    Keyword = "",
    Snippet = "",
    Color = "",
    File = "",
    Reference = "",
    Folder = "",
    EnumMember = "",
    Constant = "",
    Struct = "",
    Event = "",
    Operator = "",
    TypeParameter = "",
}

local borderstyle = {
    border = { "╭", "─", "╮", "│", "╯", "─", "╰", "│" },
    winhighlight = "Normal:CmpPmenu,CursorLine:PmenuSel,Search:None",
}

cmp.setup {
    snippet = {
        expand = function(args)
            luasnip.lsp_expand(args.body)
        end,
    },
    mapping = cmp.mapping.preset.insert({
        ["<M-k>"] = cmp.mapping.select_prev_item(), -- select suggestion up
        ["<M-j>"] = cmp.mapping.select_next_item(), -- select suggestion down
        ["<M-i>"] = cmp.mapping(cmp.mapping.scroll_docs(-1), { "i", "c" }), -- scroll docs up
        ["<M-o>"] = cmp.mapping(cmp.mapping.scroll_docs(1), { "i", "c" }), -- scroll docs down
        ["<C-Space>"] = cmp.mapping(cmp.mapping.complete(), { "i", "c" }),
        ["<C-y>"] = cmp.config.disable,
        ["<C-e>"] = cmp.mapping {
            i = cmp.mapping.abort(),
            c = cmp.mapping.close(),
        },
        ["<CR>"] = cmp.mapping.confirm { select = true },
    }),
    formatting = {
        fields = { "kind", "abbr", "menu" },
        format = function(entry, vim_item)
            vim_item.kind = string.format("%s", kind_icons[vim_item.kind])
            vim_item.menu = ({
                nvim_lsp = "[LSP]",
                luasnip = "[Snippet]",
                buffer = "[Buffer]",
                path = "[Path]",
            })[entry.source.name]
            return vim_item
        end,
    },
    sources = {
        { name = "nvim_lsp" },
        { name = "luasnip" },
        { name = "buffer" },
        { name = "path" },
        { name = "nvim_lua" },
    },
    confirm_opts = {
        behavior = cmp.ConfirmBehavior.Replace,
        select = false,
    },
    window = {
        completion = borderstyle,
        documentation = borderstyle,
    },
    experimental = {
        ghost_text = false,
        native_menu = false,
    },
}

csnip.lazy_load { paths = vim.fn.stdpath "config" .. "/snippets" }

Add the following to your init.lua file

require('user.lsp.nvim-lsp')
require('user.lsp.nvim-cmp')

Result Screenshots

CMP

Buff Hover

Snippet

Signature Help