"class" on svelte:component doesn't seem to properly compile

[halvves]

Describe the bug

I'm fairly new to Svelte, so bear with me if this isn't really a bug, but if I try to pass a class to a component using <svelte:component />

1. The styles don't seem to compile
2. I get the "unused css selector" warning

I would expect to be able to pass a class to a component this way and everything compile per usual.

Reproduction

quick repro: https://svelte.dev/repl/d3b523dbff6c48c4b8ec9ec2f4eb3a0d

general idea:

<script>
  import CoolDivA from './CoolDivA.svelte';
	
  let selectedComponent = CoolDivA;
</script>

<svelte:component this={selectedComponent} class="c" />

<style>
  .c {
    color: red;
  }
</style>

Logs

No response

System Info

System:
    OS: macOS 12.2.1
    CPU: (10) arm64 Apple M1 Max
    Memory: 3.09 GB / 64.00 GB
    Shell: 5.8 - /opt/homebrew/bin/zsh
  Binaries:
    Node: 16.13.2 - /usr/local/bin/node
    npm: 8.1.2 - /usr/local/bin/npm
  Browsers:
    Chrome: 100.0.4896.88
    Firefox: 96.0.3
    Safari: 15.3

Severity

annoyance

[Conduitry]

class on any component (including <svelte:component>) is just another prop. It doesn't have anything to do with the HTML class attribute, and doesn't enter into styling.

[halvves]

Ah, I see. It looks like I'm just encountering another variation of #2870, and this is something not currently desired in svelte core. No worries! Thanks for the quick response! Seems this workaround may do the job for me.