Fix HMR on .localhost domains

[canac]

↪️ Pull Request

Fix HMR on .localhost domains (e.g. https://project.localhost).

Fixes #7490

💻 Examples

Before, it was trying to connect to the HMR websocket over the ws:// protocol, even though https://project.localhost is a secure domain. Now, it correctly uses the wss:// protocol.

🚨 Test instructions

Set up a project on https://project.localhost. An easy way is with caddy.

brew install caddy
printf "project.localhost {\n\treverse_proxy localhost:1234\n}\n" > $HOMEBREW_PREFIX/Caddyfile
brew services start caddy
parcel src/index.html # start a parcel project on port 1234
open https://project.localhost

Verify that the HMR websocket connection is made to wss://project.localhost/, not ws://project.localhost/

✔️ PR Todo

• Added/updated unit tests for this change
• Filled out test instructions (In case there aren't any unit tests)
• Included links to related issues/PRs

[mischnic]

This isn't specific to *.localhost though, right? It's really any domain containing "localhost" somewhere

[canac]

This isn't specific to *.localhost though, right? It's really any domain containing "localhost" somewhere

That's correct. It's the same issue with hostnames like localhost.corp.com, 127.0.0.123, and 120.0.0.0. I just encountered it on .localhost domains.