Respect server.host variable in hot file

[jessarcher]

This PR adds support for Vite's server.host setting when writing the address to the hot file.

Fixes #23

[hailwood]

@jessarcher This resolves the issue if we've manually specified the host,
If we haven't though, we still end up with 127.0.0.1 while vite defaults to localhost.

Perhaps this small update would help?

const host = configHost ?? (serverAddress === '127.0.0.1' ? 'localhost' : serverAddress)

As an aside, I think we should also be setting server.hmr.host to the same value, otherwise hmr attempts to use whatever domain we loaded the site under in our browser (e.g. I access the site in dev at https://laravel.lndo.site so it's requesting `https://laravel.lndo.site/__vite_ping and attempting to open a websocket connection to wss://laravel.lndo.site:3000)

[jessarcher]

Ahh, I see.

I worry about specifying localhost manually as it seems like that has caused issues in the past with IPv4 and IPv6, where on some systems localhost will resolve to ::1, but in your code snippet Vite will only be listening on 127.0.0.1. See here for Vite's solution. Unless we implement a similar DNS resolution, it seems safer to use the IP address unless explicitly configured to be a hostname.

In terms of the __vite_ping thing, I don't think setting server.hmr.host will fix that as Vite 2 doesn't specify any hostname when making that request, so it will always go to the web server rather than the Vite server. This has been fixed in vitejs/vite#6819 but that only made it to Vite 3.

[hailwood]

Okay, I don't mind manually specifying localhost in my config, as long as the hot file picks that up (which is what the PR is currently doing) so good to go there.

Re the __vite_ping thing, I wonder if that's more a side effect I end up seeing if the websocket connection fails, which is why I don't see it when setting the hmr host?
Setting the hmr host definitely corrects the issue for the websocket connection heading to the wrong location though.
Again I don't mind manually specifying that in my config if you'd rather wait and see if anyone else reports it as an issue though (or is a non issue when we're using vite3) :)

[timacdonald]

I know this is part of a bigger story for @hailwood, but I like this PR in isolation. It makes sense that we respect a hard coded config when present.