Bug: Undo issue with array.push

[Shubhajit01]

I am currently using @legendapp/state version 3.0.0-beta.19, and facing a strange issue with arrays and undo.

Details -

• I am storing a list of items in the observable
• I push something to the observable array - todos$.items.push(todo). It gets added as expected and react renders the new item.
• When I invoke undo
  • It replaces the item with a null instead of making the array as empty.
  • But, the undo works perfect when I do something like todos$.items.set(pre => [...pre, todo]) instead of a push

This happens when there is only one element in the array and undo is called.

Reproduction Link - https://codesandbox.io/p/sandbox/w7yn9l

Am I missing something here, or is there some conditions before using undo?