svelte-kit preview ignores port and host in svelte.config.js

[keithlayne]

Describe the bug

Looking at https://github.com/sveltejs/kit/blob/master/packages/kit/src/cli.js#L167-L187 you can see from inspection that these two config entries will always be overwritten because the options are defaulted. svelte-kit dev doesn't share this problem because these options are not defaulted.

Reproduction

1. Create a new sveltekit project via npm create svelte foobar
2. Edit svelte.config.js and set config.kit.vite.preview.port to 3001
3. Run e.g. npm run preview

Logs

Output: 


  SvelteKit v1.0.0-next.357

  local:   http://localhost:3000
  network: not exposed

  Use --host to expose server to other devices on this network

System Info

System:
    OS: Linux 5.17 Pop!_OS 22.04 LTS
    CPU: (16) x64 AMD Ryzen 7 PRO 5850U with Radeon Graphics
    Memory: 1.02 GB / 15.02 GB
    Container: Yes
    Shell: 5.8.1 - /bin/zsh
  Binaries:
    Node: 16.13.1 - ~/.asdf/installs/nodejs/16.13.1/bin/node
    Yarn: 3.2.1 - ~/.asdf/shims/yarn
    npm: 8.1.2 - ~/.asdf/plugins/nodejs/shims/npm
    Watchman: 4.9.0 - /usr/bin/watchman
  Browsers:
    Chrome: 103.0.5060.53
    Firefox: 101.0.1
  npmPackages:
    @sveltejs/adapter-auto: next => 1.0.0-next.53 
    @sveltejs/adapter-static: ^1.0.0-next.34 => 1.0.0-next.34 
    @sveltejs/kit: next => 1.0.0-next.357 
    svelte: ^3.44.0 => 3.48.0 

Severity

annoyance

Additional Information

This is a mild annoyance but a trivial fix. The only reason this isn't a PR is because I don't see any obvious way to put tests around this. If you don't care, or can point me in the right direction, I'll send a PR.

I also saw the suggestion to stop using svelte-kit preview in favor of vite preview which looks like it would make this issue moot.

[keithlayne]

Looks like I've duped #5312 somewhat.