Adding options in create() - Ex - Default Comparison - shallow.

[astrarudra]

Hi,

So here is the idea -
Currently, we need to import and use useShallow everywhere -

const { nuts, honey } = useBearStore(
  useShallow((state) => ({ nuts: state.nuts, honey: state.honey })),
)

Instead why not allow an option for the user to set a default comparison in create.
And then override if nessesary.

const useBearStore = create((set) => ({
  bears: 0,
  increasePopulation: () => set((state) => ({ bears: state.bears + 1 })),
  removeAllBears: () => set({ bears: 0 }),
}), {
  equality: shallow
})

Idea is from Zundo. It takes in equality: shallow on initiation.
Also, having options wil help in extensibility - we can add more options in future.

[dai-shi]

That's exactly what createWithEqualityFn does. Maybe we should update the docs. cc @dbritto-dev

[astrarudra]

Oh - any example of this createWithEqualityFn ?
Thanks - this is great!

[dbritto-dev]

@astrarudra sure

import { createWithEqualityFn, shallow  } from 'zustand/traditional'

const store = createWithEqualityFn((...args) => ({ ...  }), shallow)

[dai-shi]

from 'zustand/traditional'

[astrarudra]

shallow is not in 'zustand/traditional'

[dai-shi]

import { createWithEqualityFn } from 'zustand/traditional'
import { shallow } from 'zustand/shallow'