feat(explorer): file watcher when explorer is open

lua/snacks/explorer/watch.lua

@@ -0,0 +1,74 @@
+local M = {}
+
+local uv = vim.uv or vim.loop
+
+---@alias snacks.explorer.Watcher fun(path:string, opts:vim._watch.watch.Opts?, callback:vim._watch.Callback):fun()
+
+---@return snacks.explorer.Watcher?
+function M.watcher()
+  if not vim._watch then
+    return
+  end
+  if vim.fn.has("win32") == 1 or vim.fn.has("mac") == 1 then
+    return vim._watch.watch
+  elseif vim.fn.executable("inotifywait") == 1 then
+    return vim._watch.inotify
+  end
+  return vim._watch.watchdirs
+end
+
+local running = {} ---@type table<string, fun()>
+
+function M.abort()
+  for _, abort in pairs(running) do
+    abort()
+  end
+  running = {}
+end
+
+---@param cwd string
+function M.watch(cwd)
+  if running[cwd] then
+    return
+  end
+  local Tree = require("snacks.explorer.tree")
+  local watch = M.watcher()
+  if not watch then
+    return
+  end
+  M.abort()
+
+  local timer = assert(uv.new_timer())
+  local cancel = watch(cwd, {
+    uvflags = { recursive = true },
+  }, function(path)
+    -- handle deletes
+    while not uv.fs_stat(path) do
+      local p = vim.fs.dirname(path)
+      if p == path then
+        return
+      end
+      path = p
+    end
+    Tree:refresh(path)
+
+    -- batch updates and give explorer the time to update before the watcher
+    timer:start(100, 0, function()
+      local picker = Snacks.picker.get({ source = "explorer" })[1]
+      if picker and Tree:is_dirty(picker:cwd(), picker.opts) then
+        if not picker.list.target then
+          picker.list:set_target()
+        end
+        picker:find()
+      end
+    end)
+  end)
+  running[cwd] = function()
+    if not timer:is_closing() then
+      timer:close()
+    end
+    cancel()
+  end
+end
+
+return M