ckolkey / lsp-format.nvim

A wrapper around Neovims native LSP formatting.

LSP-format.nvim

LSP-format.nvim is a wrapper around Neovims native LSP formatting.

It does

1. Asynchronously formatting on save
2. Sequentially formatting with all attached LSP server
3. Add commands for disabling formatting (globally or per filetype)
4. Makes it easier to send format options to the LSP

It does not

1. Provide any formatting by itself. You still need to use an LSP server

Install

Use your favourite plugin manager to install.

Example with Packer

wbthomason/packer.nvim

-- init.lua
require("packer").startup(
    function()
        use "lukas-reineke/lsp-format.nvim"
    end
)

Example with Plug

junegunn/vim-plug

" init.vim
call plug#begin('~/.vim/plugged')
Plug 'lukas-reineke/lsp-format.nvim'
call plug#end()

Setup

To use LSP-format, you have to run the setup function, and pass the on_attach function to each LSP that should use it.

require("lsp-format").setup {}
require "lspconfig".gopls.setup { on_attach = require "lsp-format".on_attach }

or

require("lsp-format").setup {}

local on_attach = function(client)
    require "lsp-format".on_attach(client)

    -- ... custom code ...
end
require "lspconfig".gopls.setup { on_attach = on_attach }

That's it, saving a buffer will format it now.

Notes

Make sure you remove any old format on save code

You don't want to run formatting twice. If you had setup formatting on save before, remove it.
You can check if something is listening on buffer write events with :autocmd BufWritePre and :autocmd BufWritePost

:wq will not format

Because formatting is async now, you can't save and quit in the same command. The formatting results will not get back in time and Neovim will close without applying the changes.
In this case you need to use vim.lsp.buf.formatting_seq_sync()

Add this abbreviation into your dotfiles to do the right thing when doing :wq

vim.cmd [[cabbrev wq execute "lua vim.lsp.buf.formatting_seq_sync()" <bar> wq]]

order format option

order is a special format option that determines the order formatting is requested from the LSP server.

FAQ

How is it different to autocmd BufWritePre <buffer> lua vim.lsp.buf.formatting_sync()?

The main difference is that LSP-format.nvim is async. It will format on save, without blocking the editor.
And it adds some convenience with disable commands and format options.
But the end result is the same.

How do I use format options?

You can pass the format options into the setup function, or as arguments to the :Format command.
How the format options look like depends on the LSP server you are using.

As an example, mattn/efm-langserver uses ${} template syntax with which you can define your own options ${--flag:lua_variable_name}.

require "lsp-format".setup {
    typescript = { tab_width = 4 },
    yaml = { tab_width = 2 },
}
local prettier = {
    formatCommand = [[prettier --stdin-filepath ${INPUT} ${--tab-width:tab_width}]],
    formatStdin = true,
}
require "lspconfig".efm.setup {
    on_attach = require "lsp-format".on_attach,
    init_options = { documentFormatting = true },
    settings = {
        languages = {
            typescript = { prettier },
            yaml = { prettier },
        },
    },
}

Now Typescript gets formatted with 4 and YAML with 2 spaces by default.
And you can run :Format tab_width=8 to overwrite the setting and format with 8 spaces.

How do I exclude an LSP server from formatting?

To exclude a server, you have to set the clients resolved_capabilities.document_formatting to false.
Do this in the attach function, before you call require "lsp-format".on_attach(client)

local on_attach = function(client)
    client.resolved_capabilities.document_formatting = false
    require "lsp-format".on_attach(client)
end
require "lspconfig".gopls.setup { on_attach = on_attach }