add Class

Author: alex-courtis

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

lua/nvim-tree/node/init.lua

@@ -1,13 +1,14 @@
 local git = require("nvim-tree.git")
 
+local Class = require("nvim-tree.class")
+
 ---TODO #2886
 ---TODO remove all @cast
 ---TODO remove all references to directory fields:
 
 ---Abstract Node class.
 ---Uses the abstract factory pattern to instantiate child instances.
----@class (exact) BaseNode
----@field private __index? table
+---@class (exact) BaseNode: Class
 ---@field type NODE_TYPE
 ---@field explorer Explorer
 ---@field absolute_path string
@@ -20,51 +21,17 @@ local git = require("nvim-tree.git")
 ---@field watcher Watcher?
 ---@field diag_status DiagStatus?
 ---@field is_dot boolean cached is_dotfile
-local BaseNode = {}
+local BaseNode = Class:new()
 
 ---@alias Node RootNode|BaseNode|DirectoryNode|FileNode|DirectoryLinkNode|FileLinkNode
 
----@param o BaseNode?
----@return BaseNode
-function BaseNode:new(o)
-  o = o or {}
-
-  setmetatable(o, self)
-  self.__index = self
-
-  return o
-end
-
 function BaseNode:destroy()
   if self.watcher then
     self.watcher:destroy()
     self.watcher = nil
   end
 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 BaseNode: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 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

lua/nvim-tree/renderer/decorator/init.lua

@@ -1,26 +1,16 @@
+local Class = require("nvim-tree.class")
+
 local HL_POSITION = require("nvim-tree.enum").HL_POSITION
 local ICON_PLACEMENT = require("nvim-tree.enum").ICON_PLACEMENT
 
 ---Abstract Decorator
 ---Uses the factory pattern to instantiate child instances.
----@class (exact) Decorator
----@field private __index? table
+---@class (exact) Decorator: Class
 ---@field protected explorer Explorer
 ---@field protected enabled boolean
 ---@field protected hl_pos HL_POSITION
 ---@field protected icon_placement ICON_PLACEMENT
-local Decorator = {}
-
----@param o Decorator|nil
----@return Decorator
-function Decorator:new(o)
-  o = o or {}
-
-  setmetatable(o, self)
-  self.__index = self
-
-  return o
-end
+local Decorator = Class:new()
 
 ---Maybe highlight groups
 ---@param node Node