Using neovim's official LSP plugin

We all wan't LSP support when we write code even in dynamic typing language like Ruby. It's 2020 😉

The next neovim will support LSP out of the box, so I thought about giving it a try since the old plugin I was using wasn't supporting LSP's completionItem/resolve just like below

Before - autozimu/LanguageClient-neovim

no function documents.... :(

After - neovim/nvim-lsp(official LSP temporary plugin)

documents yay!

Steps

Updating Neovim

First you'll need to install the unreleased latest neovim(aka Nightly)
Here's the link for it, but if you're using Mac & homebrew, you can do it as below.

$ brew unlink neovim
$ brew install neovim --HEAD
$ nvim --version
NVIM v0.5.0-60c581b

Installing official LSP plugin

The official LSP support will be included inside the next 0.5 neovim release version, but it's a plugin ATM so you'll have to install after you install Nightly neovim

I use dein.vim for plugin management so it'll be as below

  call dein#add('neovim/nvim-lsp')

I use deoplete.nvim for autocomplete, so below is necessary in this case

  call dein#add('Shougo/deoplete.nvim')
  call dein#add('Shougo/deoplete-lsp')

Please note that neovim's default autocomplete supports nvim-lsp, so deoplete isn't required

Setting up nvim-lsp

This is the hard part for most plugins, but nvim-lsp configuration is really simple

All you have to do is add the following to you init.vim:

:lua << END
  require'nvim_lsp'.tsserver.setup{}
END

This is when you want to write typescript, if you want to write Ruby too, add the corresponding language server as below:

:lua << END
  require'nvim_lsp'.tsserver.setup{}
  require'nvim_lsp'.solargraph.setup{}
END

Don't forget to install the language server itself if you haven't

• https://github.com/neovim/nvim-lsp#tsserver
• https://github.com/neovim/nvim-lsp#solargraph

That's all! 😆

P.S.

You also might want to set belows keybinds as well 😉

nnoremap <silent>gd    <cmd>lua vim.lsp.buf.declaration()<CR>
nnoremap <silent><c-]> <cmd>lua vim.lsp.buf.definition()<CR>
nnoremap <silent>K     <cmd>lua vim.lsp.buf.hover()<CR>

Comments

[Phil Thompson]

Thanks for this. It might seem obvious to some but you also need to have TypeScript (npm install -g typescript) installed. Not so obvious if you're just writing JavaScript.

[Piotr Napierala]

You sir, saved me hours of further digging into my problem with lsp. God bless you!

[Tolik]

Hi Takehiro,
Thnks for the article.
I've followed it but when I try to call definition I get this error:

E5108: Error executing lua ...EAD-d8e6a03/share/nvim/runtime/lua/vim/lsp/callbacks.lua:331: RPC[Error] code_name = MethodNotFound, message = "server doesn't support textDocument/declaration"

:checkhealth says everything is OK. Could you please suggest how to debug/fix it?

[Takehiro Adachi]

@kukula

Hi!

What kind of LSP are you using? 👀