defx close_tree like common file explorer.

example.vim

autocmd FileType defx call s:defx_setting()
function! s:defx_setting() abort
  nnoremap <silent><buffer><expr>h defx#do_action('call', 'DefxCloseTree')
  nnoremap <silent><buffer><expr>l defx#is_directory() ? defx#do_action('open_tree') . 'j' : defx#do_action('open', 'edit')
endfunction

function! DefxCloseTree(_)
  " candidate is opend tree?
  if defx#is_opened_tree()
    return defx#call_action('close_tree')
  endif
  
  " parent is root?
  let s:candidate = defx#get_candidate()
  let s:parent = fnamemodify(s:candidate['action__path'], s:candidate['is_directory'] ? ':p:h:h' : ':p:h')
  if s:trim_right(s:parent, '/') == s:trim_right(b:defx.paths[0], '/')
    return defx#call_action('cd', ['..'])
  endif
  
  " move to parent.
  call defx#call_action('search', s:parent)
  
  " if you want close_tree immediately, enable below line.
  " call defx#call_action('close_tree')
endfunction

function! s:trim_right(str, trim)
  return substitute(a:str, printf('%s$', a:trim), '', 'g')
endfunction