extensions: Add a nerdfont.vim extension (#2741)

autoload/airline/extensions.vim

@@ -177,6 +177,11 @@ function! airline#extensions#load()
     call add(s:loaded_ext, 'netrw')
   endif
 
+  if get(g:, 'loaded_nerdfont', 0) && get(g:, 'airline#extensions#nerdfont#enabled', 1)
+    call airline#extensions#nerdfont#init(s:ext)
+    call add(s:loaded_ext, 'nerdfont')
+  endif
+
   " fzf buffers are also terminal buffers, so this must be above term.
   if exists(':FZF') && get(g:, 'airline#extensions#fzf#enabled', 1)
     call airline#extensions#fzf#init(s:ext)

autoload/airline/extensions/nerdfont.vim

@@ -0,0 +1,46 @@
+" MIT License. Copyright (c) 2026-2026 Wu Zhenyu et al
+" Plugin: https://github.com/lambdalisue/nerdfont.vim
+" vim: et ts=2 sts=2 sw=2
+
+scriptencoding utf-8
+
+if !get(g:, 'loaded_nerdfont', 0)
+  finish
+endif
+
+function! airline#extensions#nerdfont#fileformat() abort
+  if &fileformat ==# 'dos'
+    return nerdfont#platform#find('windows')
+  endif
+  if &fileformat ==# 'mac'
+    return nerdfont#platform#find('macos')
+  endif
+  if &fileformat ==# 'unix'
+    if has('unix')
+      return nerdfont#platform#find()
+    else
+      return nerdfont#platform#find('linux')
+    endif
+  endif
+endfunction
+
+function! airline#extensions#nerdfont#ffenc() abort
+  let expected = get(g:, 'airline#parts#ffenc#skip_expected_string', '')
+  let bomb     = &bomb ? '[BOM]' : ''
+  let noeolf   = &eol ? '' : '[!EOL]'
+  let ff       = strlen(&ff) ? '['.&ff.']' : ''
+  if expected is# &fenc.bomb.noeolf.ff
+    return ''
+  else
+    return &fenc.bomb.noeolf.' '.airline#extensions#nerdfont#fileformat()
+  endif
+endfunction
+
+function! airline#extensions#nerdfont#init(ext) abort
+  call airline#parts#define_function('ffenc', 'airline#extensions#nerdfont#ffenc')
+  call a:ext.add_statusline_func('airline#extensions#nerdfont#apply')
+endfunction
+
+function! airline#extensions#nerdfont#apply(...) abort
+  call airline#extensions#append_to_section('x', ' %{nerdfont#find()}')
+endfunction

autoload/airline/extensions/tabline/formatters/nerdfont.vim

@@ -0,0 +1,7 @@
+let g:airline#extensions#tabline#formatters#nerdfont#formatter = get(g:, 'airline#extensions#tabline#formatters#nerdfont#formatter', 'default')
+
+function! airline#extensions#tabline#formatters#nerdfont#format(bufnr, buffers) abort
+  " Call original formatter.
+  let originalFormatter = airline#extensions#tabline#formatters#{g:airline#extensions#tabline#formatters#nerdfont#formatter}#format(a:bufnr, a:buffers)
+  return originalFormatter . printf(' %s', nerdfont#find(bufname(a:bufnr)))
+endfunction

doc/airline.txt

@@ -955,6 +955,18 @@ neomake <https://github.com/neomake/neomake>
 * neomake warning >
   let g:airline#extensions#neomake#warning_symbol = 'W:'
 <
+-------------------------------------                   *airline-nerdfont*
+NerdFont <https://github.com/lambdalisue/nerdfont.vim>
+
+* enable/disable nerdfont integration >
+  let g:airline#extensions#nerdfont#enabled = 1
+<  default: 1
+
+* nerdfont's tabline formatter >
+  let g:airline#extensions#tabline#formatter = 'nerdfont'
+  let g:airline#extensions#tabline#formatters#nerdfont#formatter = 'default'
+<  default: 'default'
+
 -------------------------------------                   *airline-nerdtree*
 NerdTree <https://github.com/preservim/nerdtree.git>