fix(#1720): .git watch only FETCH_HEAD, HEAD, HEAD.lock, config, index (#1732)

* fix(#1720): .git watch only HEAD, config and index

* fix(#1720): .git watch only FETCH_HEAD, HEAD, HEAD.lock, config, index

Author: alex-courtis

lua/nvim-tree/explorer/watch.lua

@@ -77,7 +77,7 @@ function M.create_watcher(absolute_path)
   end
 
   M.uid = M.uid + 1
-  return Watcher:new(absolute_path, callback, {
+  return Watcher:new(absolute_path, nil, callback, {
     context = "explorer:watch:" .. absolute_path .. ":" .. M.uid,
   })
 end

lua/nvim-tree/git/init.lua

@@ -11,6 +11,16 @@ local M = {
   cwd_to_project_root = {},
 }
 
+-- Files under .git that should result in a reload when changed.
+-- Utilities (like watchman) can also write to this directory (often) and aren't useful for us.
+local WATCHED_FILES = {
+  "FETCH_HEAD", -- remote ref
+  "HEAD", -- local ref
+  "HEAD.lock", -- HEAD will not always be updated e.g. revert
+  "config", -- user config
+  "index", -- staging area
+}
+
 function M.reload()
   if not M.config.git.enable then
     return {}
@@ -149,7 +159,7 @@ function M.load_project_status(cwd)
       end)
     end
 
-    watcher = Watcher:new(utils.path_join { project_root, ".git" }, callback, {
+    watcher = Watcher:new(utils.path_join { project_root, ".git" }, WATCHED_FILES, callback, {
       project_root = project_root,
     })
   end

lua/nvim-tree/watcher.lua

@@ -58,7 +58,7 @@ function Event:start()
     else
       log.line("watcher", "event_cb '%s' '%s'", self._path, filename)
       for _, listener in ipairs(self._listeners) do
-        listener()
+        listener(filename)
       end
     end
   end)
@@ -101,14 +101,15 @@ function Event:destroy(message)
   Event._events[self._path] = nil
 end
 
-function Watcher:new(path, callback, data)
-  log.line("watcher", "Watcher:new '%s'", path)
+function Watcher:new(path, files, callback, data)
+  log.line("watcher", "Watcher:new '%s' %s", path, vim.inspect(files))
 
   local w = setmetatable(data, Watcher)
 
   w._event = Event._events[path] or Event:new(path)
   w._listener = nil
   w._path = path
+  w._files = files
   w._callback = callback
 
   if not w._event then
@@ -123,8 +124,10 @@ function Watcher:new(path, callback, data)
 end
 
 function Watcher:start()
-  self._listener = function()
-    self._callback(self)
+  self._listener = function(filename)
+    if not self._files or vim.tbl_contains(self._files, filename) then
+      self._callback(self)
+    end
   end
 
   self._event:add(self._listener)