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

Author: alex-courtis

lua/nvim-tree.lua

@@ -125,7 +125,7 @@ function M.place_cursor_on_node()
   if not node or node.name == ".." then
     return
   end
-  node = node:get_parent_of_group()
+  node = node:get_parent_of_group() or node
 
   local line = vim.api.nvim_get_current_line()
   local cursor = vim.api.nvim_win_get_cursor(0)

lua/nvim-tree/actions/finders/find-file.lua

@@ -43,6 +43,7 @@ function M.fn(path)
       return node.absolute_path == path_real or node.link_to == path_real
     end)
     :applier(function(node)
+      ---@cast node DirectoryNode
       local incremented_line = false
       if not node.group_next then
         line = line + 1

lua/nvim-tree/actions/fs/clipboard.lua

@@ -7,6 +7,8 @@ local notify = require("nvim-tree.notify")
 
 local find_file = require("nvim-tree.actions.finders.find-file").fn
 
+local DirectoryNode = require("nvim-tree.node.directory")
+
 ---@enum ACTION
 local ACTION = {
   copy = "copy",
@@ -219,7 +221,7 @@ end
 function Clipboard:do_paste(node, action, action_fn)
   if node.name == ".." then
     node = self.explorer
-  else
+  elseif node:is(DirectoryNode) then
     node = node:last_group_node()
   end
   local clip = self.data[action]

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 ",

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

@@ -6,6 +6,8 @@ local notify = require("nvim-tree.notify")
 
 local find_file = require("nvim-tree.actions.finders.find-file").fn
 
+local DirectoryNode = require("nvim-tree.node.directory")
+
 local M = {
   config = {},
 }
@@ -120,7 +122,9 @@ function M.fn(default_modifier)
       return
     end
 
-    node = node:last_group_node()
+    if node:is(DirectoryNode) then
+      node = node:last_group_node()
+    end
     if node.name == ".." then
       return
     end

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/actions/moves/parent.lua

@@ -1,6 +1,7 @@
 local view = require("nvim-tree.view")
 local utils = require("nvim-tree.utils")
-local core = require("nvim-tree.core")
+
+local DirectoryNode = require("nvim-tree.node.directory")
 
 local M = {}
 
@@ -9,33 +10,32 @@ local M = {}
 function M.fn(should_close)
   should_close = should_close or false
 
+  ---@param node Node
   return function(node)
-    local explorer = core.get_explorer()
-    node = node:last_group_node()
-    if should_close and node.open then
-      node.open = false
-      if explorer then
-        explorer.renderer:draw()
+    local dir = node:as(DirectoryNode)
+    if dir then
+      dir = dir:last_group_node()
+      if should_close and dir.open then
+        dir.open = false
+        dir.explorer.renderer:draw()
+        return
       end
-      return
     end
 
-    local parent = node:get_parent_of_group().parent
+    local parent = (node:get_parent_of_group() or node).parent
 
     if not parent or not parent.parent then
       return view.set_cursor({ 1, 0 })
     end
 
-    local _, line = utils.find_node(core.get_explorer().nodes, function(n)
+    local _, line = utils.find_node(parent.explorer.nodes, function(n)
       return n.absolute_path == parent.absolute_path
     end)
 
     view.set_cursor({ line + 1, 0 })
     if should_close then
       parent.open = false
-      if explorer then
-        explorer.renderer:draw()
-      end
+      parent.explorer.renderer:draw()
     end
   end
 end

lua/nvim-tree/actions/tree/modifiers/collapse-all.lua

@@ -3,6 +3,8 @@ local core = require("nvim-tree.core")
 local lib = require("nvim-tree.lib")
 local Iterator = require("nvim-tree.iterators.node-iterator")
 
+local DirectoryNode = require("nvim-tree.node.directory")
+
 local M = {}
 
 ---@return fun(path: string): boolean
@@ -36,8 +38,9 @@ function M.fn(keep_buffers)
   Iterator.builder(explorer.nodes)
     :hidden()
     :applier(function(n)
-      if n.nodes ~= nil then
-        n.open = keep_buffers == true and matches(n.absolute_path)
+      local dir = n:as(DirectoryNode)
+      if dir then
+        dir.open = keep_buffers and matches(dir.absolute_path)
       end
     end)
     :recursor(function(n)

lua/nvim-tree/actions/tree/modifiers/expand-all.lua

@@ -2,6 +2,8 @@ local core = require("nvim-tree.core")
 local Iterator = require("nvim-tree.iterators.node-iterator")
 local notify = require("nvim-tree.notify")
 
+local DirectoryNode = require("nvim-tree.node.directory")
+
 local M = {}
 
 ---@param list string[]
@@ -15,7 +17,7 @@ local function to_lookup_table(list)
   return table
 end
 
----@param node Node
+---@param node DirectoryNode
 local function expand(node)
   node = node:last_group_node()
   node.open = true
@@ -36,6 +38,7 @@ end
 local function gen_iterator()
   local expansion_count = 0
 
+  ---@param parent DirectoryNode
   return function(parent)
     if parent.parent and parent.nodes and not parent.open then
       expansion_count = expansion_count + 1
@@ -44,12 +47,14 @@ local function gen_iterator()
 
     Iterator.builder(parent.nodes)
       :hidden()
+    ---@param node DirectoryNode
       :applier(function(node)
         if should_expand(expansion_count, node) then
           expansion_count = expansion_count + 1
           expand(node)
         end
       end)
+    ---@param node DirectoryNode
       :recursor(function(node)
         return expansion_count < M.MAX_FOLDER_DISCOVERY and (node.group_next and { node.group_next } or (node.open and node.nodes))
       end)
@@ -61,11 +66,16 @@ local function gen_iterator()
   end
 end
 
+---Expand the directory node or the root
 ---@param node Node
 function M.fn(node)
   local explorer = core.get_explorer()
-  node = node.nodes and node or explorer
-  if gen_iterator()(node) then
+  local parent = node:as(DirectoryNode) or explorer
+  if not parent then
+    return
+  end
+
+  if gen_iterator()(parent) then
     notify.warn("expansion iteration was halted after " .. M.MAX_FOLDER_DISCOVERY .. " discovered folders")
   end
   if explorer then

lua/nvim-tree/api.lua

@@ -10,6 +10,7 @@ local keymap = require("nvim-tree.keymap")
 local notify = require("nvim-tree.notify")
 
 local DirectoryNode = require("nvim-tree.node.directory")
+local RootNode = require("nvim-tree.node.root")
 
 local Api = {
   tree = {},
@@ -137,9 +138,9 @@ Api.tree.change_root = wrap(function(...)
 end)
 
 Api.tree.change_root_to_node = wrap_node(function(node)
-  if node.name == ".." then
+  if node.name == ".." or node:is(RootNode) then
     actions.root.change_dir.fn("..")
-  elseif node.nodes ~= nil then
+  elseif node:is(DirectoryNode) then
     actions.root.change_dir.fn(node:last_group_node().absolute_path)
   end
 end)
@@ -210,13 +211,13 @@ local function edit(mode, node)
 end
 
 ---@param mode string
----@return fun(node: table)
+---@return fun(node: Node)
 local function open_or_expand_or_dir_up(mode, toggle_group)
+  ---@param node Node
   return function(node)
     if node.name == ".." then
       actions.root.change_dir.fn("..")
     elseif node:is(DirectoryNode) then
-      ---@cast node DirectoryNode
       node:expand_or_collapse(toggle_group)
     elseif not toggle_group then
       edit(mode, node)

lua/nvim-tree/class.lua

@@ -0,0 +1,40 @@
+---Generic class, useful for inheritence.
+---@class (exact) Class
+---@field private __index? table
+local Class = {}
+
+---@param o Class?
+---@return Class
+function Class:new(o)
+  o = o or {}
+
+  setmetatable(o, self)
+  self.__index = self
+
+  return o
+end
+
+---Object is an instance of class
+---This will start with the lowest class and loop over all the superclasses.
+---@param class table
+---@return boolean
+function Class:is(class)
+  local mt = getmetatable(self)
+  while mt do
+    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 Class:as(class)
+  return self:is(class) and self or nil
+end
+
+return Class