mutable

What is the proper way to update a specific value inside an array without knowing its index?

I'm migrating to Valtio and I was doing it like so:

        receivedSpellReducer: (
            state: SpellState,
            payload: SerializedSpell,
        ): SpellState => ({
            ...state,
            spells: state.spells.map((spell) =>
                spell.id === payload.id