Formatting on selection not possible in Lua

[rieje]

With the suggestion from the wiki, there's no effect when triggering format on selection in a Lua file with lua_ls. In normal mode, format applies to the full file as expected.

Formatting on selection works fine a buffer with with bashls running.

Minimal reproducible config:

init.lua:

vim.pack.add({ "https://github.com/neovim/nvim-lspconfig", "https://github.com/stevearc/conform.nvim" })
require("conform").setup({
  formatters_by_ft = {
    lua = { "stylua" },
    sh = { "shfmt" },
  },
  default_format_opts = {
    lsp_format = "fallback",
  },
})

vim.keymap.set("", "<space>f", function()
  require("conform").format({}, function(err)
    if not err then
      local mode = vim.api.nvim_get_mode().mode
      if vim.startswith(string.lower(mode), "v") then
        vim.api.nvim_feedkeys(vim.api.nvim_replace_termcodes("<Esc>", true, false, true), "n", true)
      end
    end
  end)
end, { desc = "Format code" })

vim.lsp.enable({ "bashls", "lua_ls" })

P.S. Is async required for the mapping? If not, I think it should be omitted and prefer defaults.