Bug with slot props variables

[wsjscss]

Repl

https://svelte.dev/repl?version=3.1.0&gist=0597c56d480e14ebe6b5aa7017dd7051

Problem

I try to expose value from <slot>, but get undefined

Solving methods

1. Create variable with export

// Cnt.svelte
<script>
    export let worldText = "world";
</script>

2. Create empty variable and store data later

// Cnt.svelte
<script>
    let worldText;
    worldText = "world"
</script>

Why I can't declare variable like usually?

let worldText = "world" 

[just214]

I might be wrong here, but I believe this is intentional to maintain a one-way data flow and the slot is only able to expose data that was passed down as props from the parent. Similar to the concept of scoped slots in Vue or render props in React.

[just214]

I was playing around with this again today and see what you mean. I am not sure the reason why you can't create a variable and define it's value in a one-liner. Perhaps it has something to do with the reactivity, but your guess is as good as mine. Hopefully someone will chime in soon and shed some light.

[TehShrike]

Well that's weird. I'm not sure why it breaks in that example but not in https://svelte.dev/examples#slot-props

[LostKobrakai]

The difference seems to be that scalar values don't work, but object (and maybe array, can't remember exactly) do.

[ktquez]

It's True, objects and arrays work

[Rich-Harris]

Fixed at last in 3.6.2, thank you! https://svelte.dev/repl/0597c56d480e14ebe6b5aa7017dd7051?version=3.6.2