[mini.files] Auto-expand empty & nested dirs

[iparnelly]

I wrote a quick autocommand to automatically traverse directories that are empty outside of a single nested directory.

Screen.Recording.2024-08-29.at.2.40.58.PM.mov

Directory Structure for demo above:

> tree

.
├── README.md
└── a
    └── b
        └── c
            ├── d
            │   └── e
            │       └── node.lua
            └── node.lua

6 directories, 3 files

Implementation

I basically just check if there is only 1 line in the buffer, and confirm that the entry is a directory. If it is, then I call go_in.

I'm not lua-fluent (or even vim-api fluent) so if there are any issues you see that this might run into, let me know!

I ran into a nice recursive loop situation, hence the vim.schedule. Otherwise, things are pretty straightforward.

Code:

vim.api.nvim_create_autocmd({ "User" }, {
  pattern = { "MiniFilesWindowOpen" },
  group = require("config.autocmds").create_augroup_name("minifiles_auto_expand"),
  callback = function(data)
    local bufnr = data.data.buf_id
    local line_count = vim.api.nvim_buf_line_count(bufnr)
    if line_count ~= 1 then
      return
    end

    local entry = require("mini.files").get_fs_entry(bufnr, 1)
    if entry and entry.fs_type == "directory" then
      vim.schedule(function()
        require("mini.files").go_in()
      end)
    end
  end,
})

Thanks

[echasnovski]

Thanks for sharing! This looks nice!

The way I'd approach this, though, is via custom mapping. This looks more robust than MiniFilesWindowOpen autocommand (mainly because it will also work when windows are still open). So something like this:

local expand_single_dir
expand_single_dir = vim.schedule_wrap(function()
  local is_one_dir = vim.api.nvim_buf_line_count(0) == 1 and (MiniFiles.get_fs_entry() or {}).fs_type == 'directory'
  if not is_one_dir then return end
  MiniFiles.go_in()
  expand_single_dir()
end)

local go_in_and_expand = function()
  MiniFiles.go_in()
  expand_single_dir()
end

vim.api.nvim_create_autocmd('User', {
  pattern = 'MiniFilesBufferCreate',
  callback = function(args) vim.keymap.set('n', 'l', go_in_and_expand, { buffer = args.data.buf_id }) end,
})

require('mini.files').setup({ mappings = { go_in = '' } })

Mapping's LHS can be change to be something other than l, which is mostly a matter of taste here.

[iparnelly]

Hey thanks for the feedback!

I didn't follow this though, can you expand?

mainly because it will also work when windows are still open

I'll take your word for it though. I ended up modifying your go_in_and_expand function to allow for passing in args to go_in() (e.g. {close_on_true})

local go_in_and_expand = function(...)
  local fs_entry = MiniFiles.get_fs_entry()
  if not fs_entry then
    return
  end

  MiniFiles.go_in(...)
  if fs_entry.fs_type == "directory" then
    expand_single_dir()
  end
end

vim.api.nvim_create_autocmd('User', {
  pattern = 'MiniFilesBufferCreate',
  callback = function(args) 
    vim.keymap.set("n", "l", function()
      go_in_and_expand({ close_on_file = true })
    end, { buffer = args.data.buf_id })
    vim.keymap.set("n", "L", function()
      go_in_and_expand()
    end, { buffer = args.data.buf_id })
  end,
})

[echasnovski]

I didn't follow this though, can you expand?

On what exactly? It creates a buffer-local mapping for every buffer inside 'mini.files' explorer. When that mapping is executed, it calls go_in() followed by a recursive "expand single directory" action. This is both more straightforward to reason about (for example, because it is executed on demand and not as a side effect of an autocommand) and should work in more cases (like when there is already an open window to the right which contains single directory; it will be skipped with this version and not skipped with MiniFilesWindowOpen autocommand).