Execute Lua code with Nvim-Lua (like luafile %)

[RayJameson]

Hello @CRAG666
Thank you for your wonderful plugin, my workflow wouldn't be the same without it.
I would like to extend plugin functionality with my idea:

Problem:
When I run lua code I can use something like:

require("code_runner").setup {
    filetype = {
        lua = "lua",
    },
}

and it works fine, but it uses system binary for running code and if you want to run nvim-lua interpretator you should use luafile % but output of this command is ugly and you can't do anything with it like move around/copy etc.

I wrote function and command for it to make it look better so I wonder if you would like to make it default for running Lua code since LuaJit comes with Nvim natively.

Also it would be useful because you can run NeoVim functions like this

I don't have experience for writing plugins and would appreciate some guidance if you like my idea.

My Lua function:

---Run Lua code like `luafile %` but in new window instead of default output
---@param fargs table Getting this argument from command call like `BetterLuaFile` /path/to/file default: %
---@param orientation "horizontal"|"vertical" Orientation of created window
---@param size integer Size of created window
---@param focus boolean Focus created window
local function better_luafile(fargs, orientation, size, focus)
  local file = fargs[1] or "%"
  orientation = orientation or "horizontal"
  size = size or 15
  focus = focus or true
  local error = vim.log.levels.ERROR
  -- Get code run output
  local original_window_number = vim.api.nvim_get_current_win()
  local code_run_output = vim.fn.execute(("luafile %s"):format(file))
  local code_output_table = vim.split(code_run_output, "\n", {})
  -- Make new window
  if orientation == "horizontal" then
      vim.cmd(("%i split"):format(size))
  elseif orientation == "vertical" then
      vim.cmd(("%i vsplit"):format(size))
  else
      local error_msg = ("Wrong orientation settings: '%s'\nShould be 'vertical' or 'horizontal'"):format(
          orientation
      )
      vim.schedule(function() vim.notify(error_msg, error, { title = "BetterLuafile" }) end)
      return
  end
  local new_window_number = vim.api.nvim_get_current_win()
  -- Create new and set buffer in just created window
  local new_buffer_number = vim.api.nvim_create_buf(false, true)
  vim.api.nvim_win_set_buf(new_window_number, new_buffer_number)
  -- Write code_output_table to new buffer
  vim.api.nvim_buf_set_lines(new_buffer_number, 0, -1, false, code_output_table)
  -- Disable number and relativenumber for better look
  vim.api.nvim_win_set_option(new_window_number, "number", false)
  vim.api.nvim_win_set_option(new_window_number, "relativenumber", false)
  -- Prevent edit as we only outputting information
  vim.api.nvim_buf_set_option(new_buffer_number, "modifiable", false)
  -- Focus on original window if needed
  if not focus then
      vim.api.nvim_set_current_win(original_window_number)
  end
end
vim.api.nvim_create_user_command(
  "BetterLuafile",
  function(opts) better_luafile(opts.fargs, "horizontal", 15, true) end,
  { nargs = "?" }
)

[CRAG666]

@RayJameson Could you show me a screenshot showing me what that code does?

[RayJameson]

@CRAG666 Sure, here is comparison:

luafile %

"better" luafile %

[CRAG666]

Pleace PR