Can we add delay before formatting "on save" ?

[ls-devs]

I have some conflict using formatters and code actions.
I personally prefer triggerring formatiting with InsertLeave event, because with BufWritePost, or BufWritePre, when I hit 'Enter' between curly braces to make a newline, formatting is triggered , curly braces are closed and cursor stay on newline position.
I also prefer format on save to not add an action to format file.

But, when I use some code_actions (like whit eslint_d), file is formatted BEFORE the code_action did his job. So code_actions are not working.

So my question is : can I add some delay before formatter actually format the file ? like {delay: 1000} or something like this ?

Here's my null-ls config :

local mason_null_ls = require("mason-null-ls")

if not mason_null_ls then
	return
end

local null_ls = require("null-ls")

if not null_ls then
	return
end

mason_null_ls.setup({
	automatic_installation = false,
	ensure_installed = {
		"stylua",
		"eslint_d",
		"prettierd",
		"rustfmt",
		"black",
		"prismaFmt",
	},
})

local augroup = vim.api.nvim_create_augroup("LspFormatting", {})

null_ls.setup({
	border = "rounded",
	sources = {
		null_ls.builtins.diagnostics.pylint,
		null_ls.builtins.diagnostics.eslint_d,
		null_ls.builtins.diagnostics.cpplint,
		null_ls.builtins.diagnostics.cmake_lint,
		null_ls.builtins.formatting.stylua,
		null_ls.builtins.formatting.prismaFmt,
		null_ls.builtins.formatting.prettierd,
		null_ls.builtins.formatting.black,
		null_ls.builtins.formatting.rustfmt,
		null_ls.builtins.formatting.clang_format,
		null_ls.builtins.formatting.cmake_format,
	},
	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("InsertLeave", {
				group = augroup,
				buffer = bufnr,
				callback = function()
					vim.lsp.buf.format({
						bufnr = bufnr,
						timeout_ms = 2200,
						filter = function()
							return client.name == "null-ls"
						end,
					})
				end,
			})
		end
	end,
})

[jose-elias-alvarez]

Not sure this is something we'd want to support, since to my knowledge this isn't supported by any actual LSP servers. If all you want is a delay, you should be able to achieve what you want using timers (untested, but it should get you on the right track):

local delay = 1000
local format_timer = vim.loop.new_timer()

-- use as vim.api.nvim_create_autocmd callback
local on_insert_leave = function()
    format_timer:start(delay, 0, function()
        vim.lsp.buf.format() -- add relevant options
    end)
end

-- you also probably want to stop the timer on insert re-entry to avoid issues
local on_insert_enter = function()
    format_timer:stop()
end

[ls-devs]

Thanks a lot for the clarifications.
I'll try to implement your code, but I'll probably end up using a keybind to format.
Even if this add one more action, it gives more control.