chore: add type annotations and resolve LSP warnings (#2555)

* chore: add type annotations to (almost) all functions

* stylua

* Add classes for symlink nodes

* Replace deprecated `@vararg`

* Move node classes to `node` module

* Fix `Symlink*` classes

* add vim and libuv runtime for luals, qualify libuv types

* add scripts/luals-check, not quite ready for CI

* additional nil checks for git/init.lua and git/runner.lua

* additional nil checks for nvim-tree.lua

* wrap vim.cmd-as-a-function calls inside functions

* vim.tbl_filter predicate returns booleans

* Revert "add scripts/luals-check, not quite ready for CI"

This reverts commit c70229cad9.

* Add `MinimalNode` class in `marks` module

* Fix various LSP warnings

* stylua

* Fix `Explorer` class, update related annotations and add necessary checks

* Add missing annotations to `live-filter`

* Add temporary aliases for `uv.*` types

* Resolve remaining LSP warnings

* Revert changes not related to internal types

* Minor adjustments

* Update doc comments style

* Minor adjustments (pt. 2)

---------

Co-authored-by: Alexander Courtis <alex@courtis.org>

lua/nvim-tree/actions/fs/create-file.lua

@@ -8,6 +8,7 @@ local find_file = require("nvim-tree.actions.finders.find-file").fn
 
 local M = {}
 
+---@param file string
 local function create_and_notify(file)
   events._dispatch_will_create_file(file)
   local ok, fd = pcall(vim.loop.fs_open, file, "w", 420)
@@ -19,6 +20,8 @@ local function create_and_notify(file)
   events._dispatch_file_created(file)
 end
 
+---@param iter function iterable
+---@return integer
 local function get_num_nodes(iter)
   local i = 0
   for _ in iter do
@@ -27,6 +30,8 @@ local function get_num_nodes(iter)
   return i
 end
 
+---@param node Node
+---@return string
 local function get_containing_folder(node)
   if node.nodes ~= nil then
     return utils.path_add_trailing(node.absolute_path)
@@ -35,11 +40,18 @@ local function get_containing_folder(node)
   return node.absolute_path:sub(0, -node_name_size - 1)
 end
 
+---@param node Node|nil
 function M.fn(node)
+  local cwd = core.get_cwd()
+  if cwd == nil then
+    return
+  end
+
   node = node and lib.get_last_group_node(node)
   if not node or node.name == ".." then
     node = {
-      absolute_path = core.get_cwd(),
+      absolute_path = cwd,
+      name = "",
       nodes = core.get_explorer().nodes,
       open = true,
     }