detect correct formatter

.config/nvim/lua/funcs.lua

@@ -22,6 +22,18 @@ function M.lazy_load(tb)
   })
 end
 
+function M.on_file_open(plugin_name)
+  M.lazy_load {
+    events = { "BufRead", "BufWinEnter", "BufNewFile" },
+    augroup_name = "BeLazyOnFileOpen" .. plugin_name,
+    plugin = plugin_name,
+    condition = function()
+      local file = vim.fn.expand "%"
+      return file ~= "NvimTree_1" and file ~= "[packer]" and file ~= ""
+    end,
+  }
+end
+
 function M.gitsigns()
   vim.api.nvim_create_autocmd({ "BufRead" }, {
     group = vim.api.nvim_create_augroup("GitSignsLazyLoad", { clear = true }),
@@ -37,18 +49,6 @@ function M.gitsigns()
   })
 end
 
-function M.on_file_open(plugin_name)
-  M.lazy_load {
-    events = { "BufRead", "BufWinEnter", "BufNewFile" },
-    augroup_name = "BeLazyOnFileOpen" .. plugin_name,
-    plugin = plugin_name,
-    condition = function()
-      local file = vim.fn.expand "%"
-      return file ~= "NvimTree_1" and file ~= "[packer]" and file ~= ""
-    end,
-  }
-end
-
 function M.bootstrap()
   local fn = vim.fn
   local install_path = fn.stdpath('data')..'/site/pack/packer/start/packer.nvim'
@@ -100,6 +100,28 @@ function M.map(section)
   end
 end
 
+function M.format_filter(client)
+  local filetype = vim.bo.filetype
+  local n = require "null-ls"
+  local s = require "null-ls.sources"
+  local method = n.methods.FORMATTING
+  local available_formatters = s.get_available(filetype, method)
+
+  if #available_formatters > 0 then
+    return client.name == "null-ls"
+  elseif client.supports_method "textDocument/formatting" then
+    return true
+  else
+    return false
+  end
+end
+
+function M.format(opts)
+  opts = opts or {}
+  opts.filter = opts.filter or M.format_filter
+  return vim.lsp.buf.format(opts)
+end
+
 -- Modified version of a function stolen from LunarVim
 function M.buf_kill(kill_command, bufnr, force)
   kill_command = kill_command or "bd"