Fix wrong "slot" property warning (runtime)

[ZerdoX-x]

Repl with error: https://svelte.dev/repl/421c409d2bca424b97d18791f4af4c08?version=3.35.0
When you use slot property on component you get wrong warning.

Before submitting the PR, please make sure you do the following

• This message body should clearly illustrate what problems it solves.
• Ideally, include a test that fails without this PR but passes with it.

Tests

• Run the tests with npm test and lint the project with npm run lint

[ZerdoX-x]

Could anyone review this? Tell me if something wrong. This is my first pull request :)

[peopledrivemecrazy]

You are trying to use slot as a prop instead of how the slot is supposed to be used.

https://svelte.dev/repl/d6cc1555cae24c7b97185062e50363d4?version=3.35.0

AFAIK slot needs HTML inside them.

[ZerdoX-x]

You are trying to use slot as a prop instead of how the slot is supposed to be used.

@peopledrivemecrazy But in your REPL you are using slot as a regular prop. In REPL that I've provided I am using feature released in svelte some weeks ago.
I want to pass some component as slot's root element for another component.
Before update it was possible only to pass it with redundant wrapper:

<A>
  <span slot="slotname">
    <B />
  </span>
</A>

And now I am trying to use slotted components #1037 like this: (but I get warning)

<A>
  <B slot="slotname" />
</A>

Where slot property is used directly how it supposed to be used.

[ZerdoX-x]

I have updated my REPL with real usecase & naming and not just "A" and "B"

[stevenpwaters]

@peopledrivemecrazy #4556 introduced <Component slot="name" /> as sugar for wrapping the component in the new <svelte:fragment> custom element. There's a pending update to the docs as #6097.

To support this new shorthand pattern while avoiding the warning you'd need to export a (probably unused) slot prop on every component that you may end up using directly in a named slot. I think it's far more desirable for the warning to be disabled for this case, as with this PR.

So +1

[dummdidumm]

@tanhauhau this looks good to me. Could you take one more look and merge if it looks good to you, too?

[Conduitry]

Released in 3.39.0 - thank you!