chore(watchers): refactor events and make debouncer safe

- fs poll -> fs events
- make debouncer safe and fix diagnostics events

lua/nvim-tree/explorer/common.lua

@@ -43,6 +43,16 @@ function M.update_git_status(node, parent_ignored, status)
   end
 end
 
+function M.node_destroy(node)
+  if not node then
+    return
+  end
+
+  if node.watcher then
+    node.watcher:destroy()
+  end
+end
+
 function M.setup(opts)
   M.config = {
     git = opts.git,

lua/nvim-tree/explorer/init.lua

@@ -2,6 +2,7 @@ local uv = vim.loop
 
 local git = require "nvim-tree.git"
 local watch = require "nvim-tree.explorer.watch"
+local common = require "nvim-tree.explorer.common"
 
 local M = {}
 
@@ -33,22 +34,16 @@ function Explorer:expand(node)
   self:_load(node)
 end
 
-function Explorer.clear_watchers_for(root_node)
+function Explorer:destroy()
   local function iterate(node)
-    if node.watcher then
-      node.watcher:stop()
+    common.node_destroy(node)
+    if node.nodes then
       for _, child in pairs(node.nodes) do
-        if child.watcher then
-          iterate(child)
-        end
+        iterate(child)
       end
     end
   end
-  iterate(root_node)
-end
-
-function Explorer:_clear_watchers()
-  Explorer.clear_watchers_for(self)
+  iterate(self)
 end
 
 function M.setup(opts)

lua/nvim-tree/explorer/reload.lua

@@ -69,7 +69,12 @@ function M.reload(node, status)
   node.nodes = vim.tbl_map(
     update_status(nodes_by_path, node_ignored, status),
     vim.tbl_filter(function(n)
-      return child_names[n.absolute_path]
+      if child_names[n.absolute_path] then
+        return child_names[n.absolute_path]
+      else
+        common.node_destroy(n)
+        return nil
+      end
     end, node.nodes)
   )
 

lua/nvim-tree/explorer/watch.lua

@@ -46,7 +46,7 @@ function M.create_watcher(absolute_path)
   end
 
   log.line("watcher", "node start '%s'", absolute_path)
-  Watcher.new {
+  return Watcher.new {
     absolute_path = absolute_path,
     interval = M.interval,
     on_event = function(opts)