SOCKS Proxy support?

[jfahrenkrug]

It's difficult for me to find out whether or not make-fetch-happen (and by extension npm) fully supports SOCKS proxies (esp. 5 and 5h).

socks5h:// would be great, so that DNS requests could be handled on "the other side" of the proxy. This would make the following possible:

• working with private npm registries that only exist inside of a corporate network
• connecting to that corporate network through an SSH tunnel which is locally exposed as a SOCKS proxy

I do see SOCKS mentioned here https://github.com/zkat/make-fetch-happen/pull/28/files but I haven't been able to successfully run npm commands through a SOCKS proxy. Any help is appreciated, thanks!