Deeply reactive query result

[thomasballinger]

The React client doesn't do this either yet, but it would nice to provide fine-grained reactivity by diffing query results to produce a series of modifications on a deeply reactive Svelte object.

[thomasballinger]

I looked into this a little, something like https://github.com/benjamine/jsondiffpatch could be used. This could look like

• find undiffable types (maybe just ArrayBuffer?) and bail out to a full object update
• diff the unreactive versions of these objects
• apply that diff to the reactive object. jsondiffpatch provides one that might just work, or else reimplement the patcher.

We could use _id as the identity heuristic in arrays.

List views are the number one use case here, a first pass could operate only on query results that are arrays at the top level.

[thomasballinger]

TanStack query calls this "structural sharing," so it's sort of a normal thing to provide. Curious how svelte-query implements it.