fix(#1555): incorrect exe highlight in Windows filesystem from WSL (#1557)

lua/nvim-tree/explorer/node-builders.lua

@@ -4,6 +4,7 @@ local watch = require "nvim-tree.explorer.watch"
 
 local M = {
   is_windows = vim.fn.has "win32" == 1,
+  is_wsl = vim.fn.has "wsl" == 1,
 }
 
 function M.folder(parent, absolute_path, name)
@@ -24,9 +25,19 @@ function M.folder(parent, absolute_path, name)
   }
 end
 
-function M.is_executable(absolute_path, ext)
+function M.is_executable(parent, absolute_path, ext)
   if M.is_windows then
     return utils.is_windows_exe(ext)
+  elseif M.is_wsl then
+    if parent.is_wsl_windows_fs_path == nil then
+      -- Evaluate lazily when needed and do so only once for each parent
+      -- as 'wslpath' calls can get expensive in highly populated directories.
+      parent.is_wsl_windows_fs_path = utils.is_wsl_windows_fs_path(absolute_path)
+    end
+
+    if parent.is_wsl_windows_fs_path then
+      return utils.is_wsl_windows_fs_exe(ext)
+    end
   end
   return uv.fs_access(absolute_path, "X")
 end
@@ -37,7 +48,7 @@ function M.file(parent, absolute_path, name)
   return {
     type = "file",
     absolute_path = absolute_path,
-    executable = M.is_executable(absolute_path, ext),
+    executable = M.is_executable(parent, absolute_path, ext),
     extension = ext,
     fs_stat = uv.fs_stat(absolute_path),
     name = name,

lua/nvim-tree/explorer/reload.lua

@@ -86,7 +86,7 @@ function M.reload(node, status)
       else
         local n = nodes_by_path[abs]
         if n then
-          n.executable = builders.is_executable(abs, n.extension or "")
+          n.executable = builders.is_executable(n.parent, abs, n.extension or "")
           n.fs_stat = fs_stat_cached(abs)
         end
       end

lua/nvim-tree/utils.lua

@@ -10,6 +10,7 @@ local M = {
 }
 
 M.is_windows = vim.fn.has "win32" == 1 or vim.fn.has "win32unix" == 1
+M.is_wsl = vim.fn.has "wsl" == 1
 
 function M.path_to_matching_str(path)
   return path:gsub("(%-)", "(%%-)"):gsub("(%.)", "(%%.)"):gsub("(%_)", "(%%_)")
@@ -171,8 +172,11 @@ end
 ---@return boolean
 function M.is_windows_exe(ext)
   if not M.pathexts then
-    local PATHEXT = vim.env.PATHEXT or ""
-    local wexe = vim.split(PATHEXT:gsub("%.", ""), ";")
+    if not vim.env.PATHEXT then
+      return false
+    end
+
+    local wexe = vim.split(vim.env.PATHEXT:gsub("%.", ""), ";")
     M.pathexts = {}
     for _, v in pairs(wexe) do
       M.pathexts[v] = true
@@ -182,6 +186,44 @@ function M.is_windows_exe(ext)
   return M.pathexts[ext:upper()]
 end
 
+--- Check whether path maps to Windows filesystem mounted by WSL
+-- @param path string
+-- @return boolean
+function M.is_wsl_windows_fs_path(path)
+  -- Run 'wslpath' command to try translating WSL path to Windows path.
+  -- Consume stderr output as well because 'wslpath' can produce permission
+  -- errors on some files (e.g. temporary files in root of system drive).
+  local handle = io.popen('wslpath -w "' .. path .. '" 2>/dev/null')
+  if handle then
+    local output = handle:read "*a"
+    handle:close()
+
+    return string.find(output, "^\\\\wsl$\\") == nil
+  end
+
+  return false
+end
+
+--- Check whether extension is Windows executable under WSL
+-- @param ext string
+-- @return boolean
+function M.is_wsl_windows_fs_exe(ext)
+  if not vim.env.PATHEXT then
+    -- Extract executable extensions from within WSL.
+    -- Redirect stderr to null to silence warnings when
+    -- Windows command is executed from Linux filesystem:
+    -- > CMD.EXE was started with the above path as the current directory.
+    -- > UNC paths are not supported. Defaulting to Windows directory.
+    local handle = io.popen 'cmd.exe /c "echo %PATHEXT%" 2>/dev/null'
+    if handle then
+      vim.env.PATHEXT = handle:read "*a"
+      handle:close()
+    end
+  end
+
+  return M.is_windows_exe(ext)
+end
+
 function M.rename_loaded_buffers(old_path, new_path)
   for _, buf in pairs(a.nvim_list_bufs()) do
     if a.nvim_buf_is_loaded(buf) then