fix(compile) schedule loading to after event

[AckslD]

As reported in AckslD/nvim-neoclip.lua#26 it seems that autocommands defined in config are called twice if plugin is loaded by an event. To reproduce one can try the following small example:

    use {
        '~/some_path',
        event = 'TextYankPost',
        config = function()
            local count = 0
            _G.test_handler = function()
                count = count + 1
                print('called', count, 'times')
            end
            vim.cmd([[autocmd TextYankPost * lua _G.test_handler()]])
        end,
    }

(where ~/some_path is some existing path)

If you compile this and yank something you will see called 2 times. Unless I'm mistaken this happens since the package (and config) is loaded while handling the event so the autocommand will be added and still executed. But also doautocmd is called which triggers the handler again.

This PR puts the loading in vim.schedule and will thus be handled after the event is "finished".

[wbthomason]

Thanks, and nice job tracking down this issue! I wonder if it might be better to instead use schedule_wrap on the definition of packer.load - if doing so has the same effect (which I expect it should) as this change, I prefer that approach as it's a bit cleaner. What do you think, @AckslD?

[AckslD]

@wbthomason Yeah that's cleaner indeed, however it does not seem to work at least in my setup and breaks other things. I guess because for other loading triggers (ft, keys etc) there is no corresponding doautocmd?

We could add another function somewhere (not sure where exactly) which is

schedule_load = vim.schedule_wrap(require("packer.load"))

which is only used when event is used?

Btw I have to give credit to @tjdevries and his video without which it would have taken me much longer to understand what was going on here :)

[wbthomason]

Hmm. schedule_wrap-ing packer.load does work in my testing, and doesn't appear to break things. To make sure we're on the same page, I'm modifying only this line:

packer.nvim/lua/packer/load.lua

Line 127 in 5972ba5

return load_wrapper

to read

return vim.schedule_wrap(load_wrapper)

which, with your example spec, prints "called 1 times" as expected (I can reproduce the issue if I don't use schedule_wrap).

Do you have an example of what this breaks for you? I didn't notice any breakage, but it's possible I just didn't test sufficiently extensively.

[AckslD]

@wbthomason Doing the change you mention above seems to break for me to lazy load by module. Does that work for you?

[wbthomason]

Hmm, that works for me. For example, my telescope config uses module loading:

    {
      'nvim-telescope/telescope.nvim',
      requires = {
        'nvim-lua/popup.nvim',
        'nvim-lua/plenary.nvim',
        'telescope-frecency.nvim',
        'telescope-fzf-native.nvim',
      },
      wants = {
        'popup.nvim',
        'plenary.nvim',
        'telescope-frecency.nvim',
        'telescope-fzf-native.nvim',
      },
      setup = [[require('config.telescope_setup')]],
      config = [[require('config.telescope')]],
      cmd = 'Telescope',
      module = 'telescope',
    },

and works as expected with this change. Do you have an example of what breaks for you?

[AckslD]

@wbthomason I think what breaks for me is that I have some plugins which gets loaded by module which are in turn called in the config of another plugin.

For example this is my lsp setup:

    use { -- lspconfig {{{
        'neovim/nvim-lspconfig',
        requires = {
            {'ray-x/lsp_signature.nvim', module = 'lsp_signature'},
            { -- {{{ null-ls
                'jose-elias-alvarez/null-ls.nvim',
                module = 'null-ls',
                config = 'require("plugin_settings.null_ls").config()',
            }, -- }}}
        },
        config = 'require("plugin_settings.lspconfig").config()',
    } -- }}}

which inside pluging_settings.lspconfig I call require('null-ls') which triggers the loading. Before and also with the submitted fix this works fine. However adding schedule_wrap(load_wrapper) gives the error:

Error in packer_compiled: /home/axel/.config/nvim/lua/plugin_settings/lspconfig.lua:143: module 'null-ls' not found:

Edit: Maybe it's cause I'm doing something wrong here which is not meant to be supported? I tried to also add wants but got the same error.

[AckslD]

@wbthomason any more thoughts on this? :)