Simple (a.k.a. hack) bridge that calls out to format-js-cli.
This formats JS and adds require and import type for flow that are used in
the file. See the original source code in the nuclide repo.
You can add the following settings to your vimrc:
" Set any built in classes that will be ignored
let g:formatjs_builtins='Promise,setTimeout'
" Set any built in types that will be ignored
let g:formatjs_builtintypes='Promise,ReactClass'
" Any aliases to use, format is in csv pairs
let g:formatjs_aliases='Original,NewName'