Merge 51327677ac79241919d0ca367cfadc7a6df25e93 into a494ce1c64a2637719a5c1339abf19ec7c48089c

runtime/doc/filetype.txt

@@ -794,6 +794,13 @@ To enable the recognition of Markdown comments each time after removing
 re-source "javaformat.vim" for Vim versions greater than `8.2.1397`: >
 	runtime autoload/javaformat.vim
 <
+JAVASCRIPT						*ft-javascript-plugin*
+
+To enable prettier formatting of JavaScript files, set the following variable
+in your vimrc: >
+
+	let g:javascript_formatter = 'prettier'
+
 JSON-FORMAT						*ft-json-plugin*
 
 JSON filetype can be extended to use 'formatexpr' and "json.FormatExpr()"

runtime/doc/tags

@@ -7452,6 +7452,7 @@ ft-inform-syntax	syntax.txt	/*ft-inform-syntax*
 ft-java-plugin	filetype.txt	/*ft-java-plugin*
 ft-java-syntax	syntax.txt	/*ft-java-syntax*
 ft-javascript-omni	insert.txt	/*ft-javascript-omni*
+ft-javascript-plugin	filetype.txt	/*ft-javascript-plugin*
 ft-jq-syntax	syntax.txt	/*ft-jq-syntax*
 ft-json-plugin	filetype.txt	/*ft-json-plugin*
 ft-json-syntax	syntax.txt	/*ft-json-syntax*

runtime/ftplugin/javascript.vim

@@ -70,8 +70,23 @@ let &l:define =
             \ .. '\|^\s*\(export\s\+\|export\s\+default\s\+\)*\(var\|let\|const\|function\|class\)'
             \ .. '\|\<as\>'
 
+if !empty(get(g:,'javascript_formatprg', ''))
+augroup formatprgsJavaScript
+  autocmd! * <buffer>
+  autocmd ShellFilterPost <buffer> if v:shell_error | execute 'echom "shell filter returned error " . v:shell_error . ", undoing changes"' | undo | endif
+  if g:javascript_formatprg ==# 'prettier'
+    autocmd BufWinEnter <buffer> ++once let &l:formatprg =
+              \ executable('prettier') ? 'prettier' : 'npx prettier' .
+              \ ' --stdin-filepath=%:S --parser=javascript ' .
+              \ (&textwidth > 0 ? '--print-width=' . &textwidth : '') .
+              \ ' --tab-width=' . &l:shiftwidth . (&expandtab ? '' : '--use-tabs') . ' --'
+  endif
+augroup END
+endif
+
 let b:undo_ftplugin =
             \ "setl fo< ofu< com< cms< sua< su< def< pa<"
+            \ .. !empty(g:javascript_formatprg) ? " fp<" : ""
             \ .. "| unlet! b:browsefilter b:match_ignorecase b:match_words"
 
 let &cpo = s:cpo_save