nvim/lua/plugins/lsp/null-ls.lua

local null_ls = require("null-ls")
local helpers = require("null-ls.helpers")
-- syncronous formatting
local augroup = vim.api.nvim_create_augroup("LspFormatting", {})
require("null-ls").setup({
	-- you can reuse a shared lspconfig on_attach callback here
	on_attach = function(client, bufnr)
		if client.supports_method("textDocument/formatting") then
			vim.api.nvim_clear_autocmds({ group = augroup, buffer = bufnr })
			vim.api.nvim_create_autocmd("BufWritePre", {
				group = augroup,
				buffer = bufnr,
				callback = function()
					-- on 0.8, you should use vim.lsp.buf.format({ bufnr = bufnr }) instead
					-- on later neovim version, you should use vim.lsp.buf.format({ async = false }) instead
					-- vim.lsp.buf.formatting_sync()
					vim.lsp.buf.format({
						async = false,
						bufnr = bufnr,
						filter = function(client)
							return client.name == "null-ls"
						end,
					})
				end,
			})
		end
	end,
	sources = {
		null_ls.builtins.completion.luasnip,
		null_ls.builtins.formatting.black,
		null_ls.builtins.formatting.isort,
		null_ls.builtins.diagnostics.mypy,
		null_ls.builtins.diagnostics.markdownlint,
		null_ls.builtins.diagnostics.pylint,
		-- null_ls.builtins.diagnostics.pydoclint,
		null_ls.builtins.formatting.stylua,
		null_ls.builtins.formatting.markdownlint,
		null_ls.builtins.formatting.prettier, -- handled by lsp server
		null_ls.builtins.formatting.shfmt.with({
			filetypes = { "sh", "bash" },
			extra_args = { "-i", "0", "-ci", "-sr" },
		}),
		-- null_ls.builtins.diagnostics.actionlint,
	},
})

-- null_ls.setup({
-- on_attach = function(client)
--     if client.supports_method "textDocument/formatting" then
--         vim.cmd([[
--         augroup LspFormatting
--             autocmd! * <buffer>
--             autocmd BufWritePre <buffer> lua vim.lsp.buf.format()
--         augroup END
--         ]])
--     end
-- end,
-- })