More documentation about non working reactivity

[GauBen]

Describe the bug

I often hear from other developers having issues with reactive statements doing nothing. For instance:

<script>
	export let data; // We use sveltekit
	
	$: me = data.me;
	$: hasThing = me.things.length > 0

	setContext('hasThing', hasThing); // hasThing is always undefined??
</script>

This won't work, and this behavior is documented:

https://svelte.dev/docs#component-format-script-3-$-marks-a-statement-as-reactive

I feel that this documentation is a bit underwhelming considering how often I hear about this problem.

What could help:

• A compiler warning
• A dedicated tutorial page
• A dedicated block in the documentation, around https://svelte.dev/docs#component-format-script-3-$-marks-a-statement-as-reactive
• An eslint rule
• You name it

Reproduction

Logs

No response

System Info

-

Severity

annoyance