refactor(#2886): multi instance: node group functions refactoring (#2959)

* move last_group_node to DirectoryNode

* move add BaseNode:as and more doc

* revert parameter name changes

* revert parameter name changes

* add Class

* move group methods into DN

* tidy group methods

* tidy group methods

* tidy group methods

* tidy group methods

* parent is DirectoryNode

* tidy expand all

* BaseNode -> Node

* move watcher to DirectoryNode

* last_group_node is DirectoryNode only

* simplify create-file

* simplify parent

* simplify collapse-all

* simplify live-filter

* style

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

@@ -5,6 +5,9 @@ local notify = require("nvim-tree.notify")
 
 local find_file = require("nvim-tree.actions.finders.find-file").fn
 
+local FileNode = require("nvim-tree.node.file")
+local DirectoryNode = require("nvim-tree.node.directory")
+
 local M = {}
 
 ---@param file string
@@ -29,35 +32,21 @@ 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)
-  end
-  local node_name_size = #(node.name or "")
-  return node.absolute_path:sub(0, -node_name_size - 1)
-end
-
 ---@param node Node?
 function M.fn(node)
-  local cwd = core.get_cwd()
-  if cwd == nil then
+  node = node or core.get_explorer() --[[@as Node]]
+  if not node then
     return
   end
 
-  if not node or node.name == ".." then
-    node = {
-      absolute_path = cwd,
-      name = "",
-      nodes = core.get_explorer().nodes,
-      open = true,
-    }
-  else
-    node = node:last_group_node()
+  local dir = node:is(FileNode) and node.parent or node:as(DirectoryNode)
+  if not dir then
+    return
   end
 
-  local containing_folder = get_containing_folder(node)
+  dir = dir:last_group_node()
+
+  local containing_folder = utils.path_add_trailing(dir.absolute_path)
 
   local input_opts = {
     prompt = "Create file ",