formatter/format.lua: index out of bounds

[tjex]

When calling vim.lsp.buf.format() in ["*"] = {} (for any file type), an error is thrown about an out of bound index in get_lines.

Shell command and output (optional):

E5108: Error executing lua ...ack/packer/start/formatter.nvim/lua/formatter/format.lua:61: Index out of bounds
stack traceback:
        [C]: in function 'get_lines'
        ...ack/packer/start/formatter.nvim/lua/formatter/format.lua:61: in function 'start_task'
        ...ack/packer/start/formatter.nvim/lua/formatter/format.lua:49: in function 'format'
        [string ":lua"]:1: in main chunk

Which configuration?
Type (custom or builtin): custom
Filetype: * / all
Formatter: vim.lsp.buf.format()

Configuration(s) (post all the variants you tried):

require("formatter").setup({
	logging = true,
	log_level = vim.log.levels.WARN,
	filetype = {
		-- formatters are executed in order within their own tables
		lua = {
			require("formatter.filetypes.lua").stylua,
		},
		bash = {
			require("formatter.filetypes.sh").shfmt,
		},
		javascript = {
			require("formatter.filetypes.javascript").eslint_d,
		},
		css = {
			require("formatter.filetypes.css").prettierd,
		},
		scss = {
			require("formatter.filetypes.css").prettierd,
		},
		html = {
			require("formatter.filetypes.html").prettierd,
		},
		json = {
			require("formatter.filetypes.json").prettierd,
		},

		-- for any filetype
		["*"] = {
			require("formatter.filetypes.any").remove_trailing_whitespace,
			-- formatting logic: See if formatter.nvim can do it, then check if lsp can do it,
			-- then notify if neither can do it. The keybind is then universally ":Format", as this
			-- logic is run when formatter.nvim is run.
			function()
				local formatters = require("formatter.util").get_available_formatters_for_ft(vim.bo.filetype)
				if #formatters > 0 then
					print("formatted with formatter.nvim")
					return
				end
				local lsp_clients = vim.lsp.buf_get_clients()
				-- check if there are any LSP formatters
				for _, client in pairs(lsp_clients) do
					if client.server_capabilities.document_formatting then
						vim.lsp.buf.format()
						print("formatted with lsp")
						return
					end
				end
				print("no formatters found from formatter.nvim OR lsp")
			end,
		},
	},
})

I've also tried by only calling format(), same error:

-- ... unchanged code

		["*"] = {
			function()
                                 vim.lsp.buf.format()
			end,
		},

Expected behavior

That when running vim.lsp.buf.format() via formatter.nvim that the text is formatted without error.

+ Note: I ran formatter.nvim when editing a go file (i.e. not a filetype I'm targeting).

I am able to call vim.lsp.buf.format() manually in the file and format without error.
If I simply undo the formatting and try with formatter.nvim (via :Format or :FormatWrite) I get the above error.

Actual behaviour
The error is output, and when cleared with a keypress (confirming the error), the text formats correctly.

Additional context

This has been commented on before here: #260