need-check-nil depends on the define order

[phanen]

---@diagnostic disable: unused
local M = {}

---@generic T: table
---@param orig T
---@return T
local function deepcopy(orig)
	return orig
end

local f = function()
	---@type boolean, string[]
	local cond, lines
	if cond then
		lines = M.strip_cr(lines)
	end
	lines = deepcopy(lines)
	lines[#lines] = nil
end

---@param xs0 string[]
---@return string[]
function M.strip_cr(xs0)
	return xs0
end

return M

[phanen]

reproducable in this config: nvim --clean -u config.lua a.lua

vim.lsp.config("lua_ls", {
	cmd = { "emmylua_ls" },
	filetypes = { "lua" },
	root_markers = {
		".luarc.json",
		".emmyrc.json",
		".luacheckrc",
		".git",
	},
	workspace_required = false,
})
vim.lsp.enable("lua_ls")