feat: add exclude filter list (#878)

doc/nvim-tree-lua.txt

@@ -338,6 +338,11 @@ Here is a list of the options available in the setup call:
       type: `{string}`
       default: `{}`
 
+  - |filters.exclude|: list of directories or files to exclude from filtering
+    (will always be shown)
+      type: `{string}`
+      default: `{}`
+
 *nvim-tree.trash*
 |trash|: configuration options for trashing
 

lua/nvim-tree.lua

@@ -441,7 +441,8 @@ local DEFAULT_OPTS = {
   },
   filters = {
     dotfiles = false,
-    custom_filter = {}
+    custom_filter = {},
+    exclude = {}
   },
   git = {
     enable = true,

lua/nvim-tree/populate.lua

@@ -5,6 +5,7 @@ local utils = require'nvim-tree.utils'
 
 local M = {
   ignore_list = {},
+  exclude_list = {},
   is_windows = vim.fn.has('win32') == 1
 }
 
@@ -122,6 +123,12 @@ end
 local function should_ignore(path)
   local basename = utils.path_basename(path)
 
+  for _, entry in ipairs(M.exclude_list) do
+    if path:match(entry) then
+      return false
+    end
+  end
+
   if M.config.filter_dotfiles then
     if basename:sub(1, 1) == '.' then
       return true
@@ -353,6 +360,8 @@ function M.setup(opts)
     filter_dotfiles = opts.filters.dotfiles,
   }
 
+  M.exclude_list = opts.filters.exclude
+
   local custom_filter = opts.filters.custom
   if custom_filter and #custom_filter > 0 then
     for _, entry in pairs(custom_filter) do