Bug with `solid-js/store` and `solid-primitives/history`
I ran into a bug and reproduced it in this stackblitz. For some reason with this configuration of the store object like this:
{ [key: number]: { image: { id: number } | undefined; } } the history object is starting to resurrect it incorrectly, like skipping the state (see in the video)
My guess is that the reconcile function is not working correctly, but I could be wrong
https://stackblitz.com/edit/solidjs-templates-jzapxh?file=src%2Ftest-todo.comopnent.tsx4 Replies
Digging deeper, it seems that the problem is in
structuredClone function
No, it's exactly a problem in the reconcile function.Okay, I don't get it at all now. It's acting really weird in general.
https://stackblitz.com/edit/solidjs-templates-88j7ru?file=src%2Ftest-todo.comopnent.tsx
I am now 100% sure that the bug is in the
reconcile function.
I was able to reproduce it here:
https://stackblitz.com/edit/typescript-fcz5m5?file=index.tsSonyStone
StackBlitz
solid-js/store reconcile bug - StackBlitz
Blank starter project for building TypeScript apps.
reconcile is always hard to follow, but I think the reason is that you reset the result to an empty object by doing
reconcile(start)(result). if result is {} the next reconcile has to reuse the whole object to fill the 0 property, so if you do reconcile(first) and reconcile(second), 0 will be assigned from first, and then that will be merged with second and the object mutated.
I think the general design with stores is that they mutate the source, so you need to clone the assigned object every time you assign it if you want to keep it untouched.
Although that is a bit annoying when doing undo history I guess.
if you need to copy when storing and copy when reconciling.
One could definitely write a smarter reconcile that clones the assigned objects, if that would be worth it.