From my view, I avoid using the wp editor at all. It doesn’t offer all the good things a IDE can provide.
If you have a local server running, you probably can access it. For example, in linux its usally on /var/www/localhost/htdocs/ but it varies a lot from distro to distro.
You can also use a IDE and push the modifications via ssh or ftp to your remote.
Without more details on your local environment, I can only suggest reading this: