perf(files): async find using fs_opendir

Switched to fs_opendir, as fs_scandir isn't asynchronous

Also may fix #127

lua/neotest/lib/file/find.lua

@@ -1,10 +1,11 @@
-local uv = vim.loop
+local async = require("neotest.async")
+local uv = async.uv
 local M = {}
 local lib = require("neotest.lib")
 
-local ignored = vim.tbl_add_reverse_lookup({
-  "node_modules",
-})
+local async_opendir = async.wrap(function(path, entries, cb)
+  return vim.loop.fs_opendir(path, cb, entries)
+end, 3)
 
 --- Find all files under the given directory.
 --- Does not search hidden directories.
@@ -18,27 +19,45 @@ function M.find(root, opts)
   local dirs_to_scan = {}
 
   local paths = {}
-  local dir, dir_handle = "", uv.fs_scandir(root)
+  local dir = ""
+  local max_entries = 1000
+  local err, dir_handle = async_opendir(root, max_entries)
+  assert(not err, err)
   while dir_handle or #dirs_to_scan > 0 do
     if not dir_handle then
       dir = table.remove(dirs_to_scan, 1)
-      dir_handle = uv.fs_scandir(dir)
+      err, dir_handle = async_opendir(dir, max_entries)
+      assert(not err, err)
     end
 
-    local name, path_type = uv.fs_scandir_next(dir_handle)
-    local rel_path = name and (dir == "" and name or (dir .. sep .. name))
+    local iter_dir = function()
+      local pending = {}
+      return function()
+        if #pending == 0 then
+          err, pending = uv.fs_readdir(dir_handle)
+          assert(not err, err)
+          if not pending then
+            uv.fs_closedir(dir_handle)
+            dir_handle = nil
+            return nil
+          end
+        end
+        return table.remove(pending)
+      end
+    end
 
-    if not name then
-      dir_handle = nil
-    elseif
-      path_type == "directory"
-      and name:sub(1, 1) ~= "."
-      and not ignored[name]
-      and (not filter_dir or filter_dir(name, rel_path, root))
-    then
-      dirs_to_scan[#dirs_to_scan + 1] = rel_path
-    elseif path_type == "file" then
-      paths[#paths + 1] = (root .. sep .. rel_path)
+    for entry in iter_dir() do
+      local name, path_type = entry.name, entry.type
+      local rel_path = name and (dir == "" and name or (dir .. sep .. name))
+      if
+        path_type == "directory"
+        and name:sub(1, 1) ~= "."
+        and (not filter_dir or filter_dir(name, rel_path, root))
+      then
+        dirs_to_scan[#dirs_to_scan + 1] = rel_path
+      elseif path_type == "file" then
+        paths[#paths + 1] = (root .. sep .. rel_path)
+      end
     end
   end
   return paths