Document $$props

[Rich-Harris]

Looks like we missed this?

[Conduitry]

It's sort of shoehorned into https://svelte.dev/tutorial/spread-props - which is probably as much as it needs to be mentioned in the tutorial - but yup needs somewhere more referency

[reinink]

Yes, was going to recommend this! I found it by browsing around in the tutorial section.

[Conduitry]

We only have one special magic global like this now, which does make deciding where to put this a bit tricky. A new number/bullet under <script>? And entirely new subsection under 'Component format'? If we do add more magic globals (like $$slots for example), would these all go in the same place and would that make it less awkward to have a new section somewhere?

[mindrones]

To me this belongs to https://svelte.dev/docs#1_export_creates_a_component_prop.

I would append a paragraph similar to the phrase used in the tutorial, like:

The variable $$props can be used to reference all the props that were passed into a component, including the ones that weren't declared with export.

Eventually I'd also add the recommendation in a blockquote:

It's not generally recommended, as it's difficult for Svelte to optimise, but it's useful in rare cases.