move add BaseNode:as and more doc

Author: alex-courtis

lua/nvim-tree/actions/moves/item.lua

@@ -78,7 +78,7 @@ local function expand_node(node)
     ---@cast node DirectoryNode
     -- Expand the node.
     -- Should never collapse since we checked open.
-    node:expand_or_collapse()
+    node:expand_or_collapse(false)
   end
 end
 
@@ -102,7 +102,7 @@ local function move_next_recursive(what, skip_gitignored)
   end
   if node_init:is(DirectoryNode) and valid and not node_init.open then
     ---@cast node_init DirectoryNode
-    node_init:expand_or_collapse()
+    node_init:expand_or_collapse(false)
   end
 
   move("next", what, skip_gitignored)

lua/nvim-tree/node/directory.lua

@@ -128,6 +128,7 @@ function DirectoryNode:last_group_node()
   return node
 end
 
+---@param toggle_group boolean
 function DirectoryNode:expand_or_collapse(toggle_group)
   toggle_group = toggle_group or false
   if self.has_children then

lua/nvim-tree/node/init.lua

@@ -42,23 +42,29 @@ function BaseNode:destroy()
   end
 end
 
----From plenary
----Checks if the object is an instance
+---Object is an instance of class
 ---This will start with the lowest class and loop over all the superclasses.
----@param self BaseNode
----@param T BaseNode
+---@param class table
 ---@return boolean
-function BaseNode:is(T)
+function BaseNode:is(class)
   local mt = getmetatable(self)
   while mt do
-    if mt == T then
+    if mt == class then
       return true
     end
     mt = getmetatable(mt)
   end
   return false
 end
 
+---Return object if it is an instance of class, otherwise nil
+---@generic T
+---@param class T
+---@return `T`|nil
+function BaseNode:as(class)
+  return self:is(class) and self or nil
+end
+
 ---@return boolean
 function BaseNode:has_one_child_folder()
   return #self.nodes == 1 and self.nodes[1].nodes and vim.loop.fs_access(self.nodes[1].absolute_path, "R") or false
@@ -202,7 +208,6 @@ function BaseNode:group_empty_folders()
   local is_root = not self.parent
   local child_folder_only = self:has_one_child_folder() and self.nodes[1]
   if self.explorer.opts.renderer.group_empty and not is_root and child_folder_only then
-    ---@cast self DirectoryNode -- TODO #2886 move this to the class
     self.group_next = child_folder_only
     local ns = child_folder_only:group_empty_folders()
     self.nodes = ns or {}