Real-time preview for props changes of JS components

• Assuming we can get the updated prop value client-side, we can update the preview by simply targeting the <astro-island> element for this component instance, and updating its props attribute. The Astro island will then automatically re-render itself client-side based on the new props.

I forget the details of how our undo/redo functionality is implemented exactly (and I see we're missing docs for it other than a one-liner 🫣), but … AFAICT this would then have to add Component Source-specific logic to perform undo+redo. It'd need to check every affected component instance when undoing/redoing, check if it's provided by the js ComponentSource plugin, and then perform this alternative.
And if and only if there's zero other component instances affected, then that's all that's needed. But if there's >=1 component instance from another component source that needs undoing/redoing, we still need to talk to the server, because the server can only update the entire preview, not a subset.

(And I bet there's more complications.)

Is there a reason we don't include the preview HTML in the undo stack? Thereby allowing all undo operations (regardless of what kinds of components are on the page) to optimistically render before the server response?

Fair question. I suspect because "memory usage will go through the roof".