Lazy loading Packer itself

[dcampos]

I'm trying to load Packer itself lazily. My spec looks like the following:

local function init_packer()
    vim.cmd('packadd packer.nvim')
    require('packer').startup({
        function(use)
            use { 'wbthomason/packer.nvim', opt = true }
        end,
        config = {
            compile_path = vim.fn.stdpath('data') .. '/plugin/packer_compiled.lua',
        }
    })
end

It's working ok, but when I open packer_compiled.lua, it looks like Packer is adding a packadd packer.nvim itself:

-- Automatically generated packer.nvim plugin loader code

if vim.api.nvim_call_function('has', {'nvim-0.5'}) ~= 1 then
  vim.api.nvim_command('echohl WarningMsg | echom "Invalid Neovim version for packer.nvim! | echohl None"')
  return
end

vim.api.nvim_command('packadd packer.nvim')
...

As I understand it, that defeats the purpose of lazy loading Packer. Is that the intended behavior or am I missing something here? Should I create an issue?

[dcampos]

I've come to the conclusion that it is intended behavior, because Packer has to be present in runtimepath in order to load other plugins. Also, I think lazy loading Packer isn't that big of an advantage, as it doesn't set up anything unless I call packer.startup().

Anyway, what I'm doing right now is setting up the commands myself and only calling packer.startup() when I run one of them. The relevant part of my Packer config is below.

local function init_packer()
  vim.cmd('packadd packer.nvim')
  require('packer').startup({
    function(use)
      use { 'wbthomason/packer.nvim', opt = true }
      -- ...
    end,
    config = {
      compile_path = vim.fn.stdpath('data') .. '/site/plugin/packer_compiled.lua',
    }
  })
end

local function lazy_packer()
  return setmetatable({}, {
    __index = function(_, key)
      init_packer()
      return require('packer')[key]
    end,

    __newindex = function(_, key, value)
      init_packer()
      require('packer')[key] = value
    end,
  })
end

_G._lazy_packer = lazy_packer()

vim.api.nvim_exec([[
  command! -nargs=* -complete=customlist,v:lua._lazy_packer.plugin_complete PackerInstall lua _lazy_packer.install(<f-args>)
  command! -nargs=* -complete=customlist,v:lua._lazy_packer.plugin_complete PackerUpdate lua _lazy_packer.update(<f-args>)
  command! -nargs=* -complete=customlist,v:lua._lazy_packer.plugin_complete PackerSync lua _lazy_packer.sync(<f-args>)
  command! PackerClean lua _lazy_packer.clean()
  command! PackerCompile packadd packer.nvim | lua _lazy_packer.compile()
  command! -nargs=+ -complete=customlist,v:lua._lazy_packer.loader_complete PackerLoad | lua _lazy_packer.loader(<q-args>)
]], false)