home: vim: use 'lsp-formatting.nvim'

A few things that are different:
* Async by default.
* Takes care of the order of formatters, if I ever need to do that.
* Allows for easily disabling formatting (unfortunately this is global
  state, not buffer-local).
* Gets rid of the formatting pause when doing `:wq`.

home/vim/default.nix

@@ -67,6 +67,7 @@ in
 
       # LSP and linting
       nvim-lspconfig # Easy LSP configuration
+      lsp-format-nvim # Simplified formatting configuration
       lsp_lines-nvim # Show diagnostics *over* regions
       null-ls-nvim # LSP integration for linters and formatters
       nvim-treesitter.withAllGrammars # Better highlighting

home/vim/lua/ambroisie/lsp.lua

@@ -1,5 +1,8 @@
 local M = {}
 
+-- Simplified LSP formatting configuration
+local lsp_format = require("lsp-format")
+
 -- shared LSP configuration callback
 -- @param client native client configuration
 -- @param bufnr int? buffer number of the attched client
@@ -30,17 +33,7 @@ M.on_attach = function(client, bufnr)
     })
 
     -- Format on save
-    if client.supports_method("textDocument/formatting") then
-        local augroup = vim.api.nvim_create_augroup("LspFormatting", {})
-        vim.api.nvim_clear_autocmds({ group = augroup, buffer = bufnr })
-        vim.api.nvim_create_autocmd("BufWritePre", {
-            group = augroup,
-            buffer = bufnr,
-            callback = function()
-                vim.lsp.buf.format({ bufnr = bufnr })
-            end,
-        })
-    end
+    lsp_format.on_attach(client, bufnr)
 
     -- Mappings
     local wk = require("which-key")

home/vim/plugin/settings/formatting.lua

@@ -0,0 +1,3 @@
+local lsp_format = require("lsp-format")
+
+lsp_format.setup({})